Shalizi on Saletan

by Henry on November 30, 2007

This has been another episode of what Cosma said

In my first post about this, I said that there were two possible interpretations of Saletan’s actions: that he didn’t know that the ideas he was spread were crap, or that he did, but spread them anyway to advance an agenda. Saying that the second interpretation was more charitable wasn’t just a joke. Sadly, this partial mea culpa supports the first interpretation, that of incompetence. To put it in “shorter William Saletan” form, what he is saying is: I am shocked — shocked! — to discover that the people who devote their careers to providing supposedly-scientific backing for racist ideas are, in fact, flaming racists. And he does seem to be shocked, though it is hard (as Yglesias says) to see why, logically, he should strain out those gnats he displays for our horrified inspection while swallowing the camel of group inferiority (and telling his readers that camel is really great and the coming thing). This indicates a level of incompetence as a reporter and researcher that is really quite stunning …

But let me back up a minute to the bit about relying on “peer review and rebuttals to expose any relevant issue”. There are two problems here. One has to do with the fact that, as I said, it is really very easy to find the rebuttals showing that Rushton’s papers, in particular, are a tragic waste of precious trees and disk-space. For example, in the very same issue of the very same journal as the paper by Rushton and Jensen which was one of Saletan’s main sources, Richard Nisbett, one of the more important psychologists of our time, takes his turn banging his head against this particular wall. Or, again, if Saletan had been at all curious about the issue of head sizes, which seems to have impressed him so much, it would have taken about five minutes with Google Scholar to find a demonstration that this is crap. So I really have no idea what Saletan means when he claimed he relied on published rebuttals — did he think they would just crawl into his lap and sit there, meowing to be read? If I had to guess, I’d say that the most likely explanation of Saletan’s writings is that he spent a few minutes with a search engine looking for hits on racial differences in intelligence, took the first few blogs and papers he found that way as The Emerging Scientific Consensus, and then stopped. But detailed inquiry into just how he managed to screw up so badly seems unprofitable.

{ 156 comments }

1

Grand Moff Texan 11.30.07 at 9:02 pm

[raises hand]

Um, does this mean that those of us who rejected this racist pseudo-science (again) aren’t “creationists” in Saletan’s mind?

Oh, that’s right: I don’t care.
.

2

Kieran Healy 11.30.07 at 9:49 pm

Cue the emergence of the second line of pseudo-serious handwringing, which is something like “Well, OK, it _may_ be that in _this_ case there is no merit to the claims Saletan was making and he really didn’t know what he was talking about at all; but just look at how _angry_ his critics got — surely we don’t want to live in a world where someone who raised these questions of Race and IQ would be risking their reputation and livelihood simply for _raising_ them, oh behold the terrible state of our discourse on race where a seemingly respectable person can’t talk out their ass in public for even a few minutes without someone who knows something about the topic irritably correcting them, for shame.”

3

Uncle Kvetch 11.30.07 at 10:02 pm

Kieran, when Sullivan posts that paragraph on his blog tomorrow, I hope you demand royalties.

4

Jim Harrison 11.30.07 at 10:30 pm

The notion that IQ correlates with race (= black people are unintelligent) is far easier to process than the scientifically defensible alternate views that reflect the complexity of the real world. Since most people, especially most conservative commentators, aren’t especially bright and almost none of them are scientifically literate, the Bell Curve thesis has built-in staying power.

5

Grand Moff Texan 11.30.07 at 10:41 pm

Whoa! As usual, the deeper I dig, the dirtier it gets:

To get a flavor of what New Century stands for, check out its publications on crime (“Everyone knows that blacks are dangerous”) and heresy (“Unless whites shake off the teachings of racial orthodoxy they will cease to be a distinct people”).

A “distinct people”? In what way are the various white-skinned people of the world a “distinct people”?

Weird, weird people.
.

6

Rickm 11.30.07 at 10:42 pm

Well then, if whitey is not a distinct people, then they’ve already lost.

7

Walt 11.30.07 at 10:49 pm

What amazes me is that this whole brouhaha has actually lowered my opinion of the racist side. On further examination, every piece of empirical evidence that the black-people-are-genetically-stupid brought up turned out to be either fatally flawed, or torn out of context.

8

Stuart 11.30.07 at 11:44 pm

What amazes me is that this whole brouhaha has actually lowered my opinion of the racist side.

Interesting that is even feasible by this point in time.

9

roger 12.01.07 at 1:03 am

The moral to the Saletan story has nothing to do with “race science” or IQ, it seems to me, but with the persistent trivilization of racism. I would bet that Saletan would indignantly reject the suggestion that he is a racist. And the reason he’d reject it is because he doesn’t ‘feel’ racist. Racism has become a matter of feeling or taste – it is like the question of whether you like chocolate or not. And thus, the systematic social aspect of racism gets nicely covered up, as it is reduced to a matter of private language, of the “heart” – that favorite of Bush’s organs. Saletan and Douthat and Sullivan, who have all expressed their belief that black people are mentally inferior, work at two pretty important media spots. Undoubtedly their attitude – which is that we are on the brink of discovering black people are inherently inferior, just give ‘race science’ another fifty years – leaks into the attitude in the office. Or might even reflect it. And that no doubt will feed into the work report on some ‘inferior’ black hire.

Imagine the difference in the reception of the article if Saletan had pressed the point, say, that doing an audit of the neurological damage done to black children by an oppressive white society was strong evidence for the case that the U.S. owed hundreds of billions of dollars in remuneration to African Americans. You could have pulled out the same bourgeois tests and made that point. But the same people who weep, figuratively, at the idea that calling people racist when they are racist is gonna prevent us from having one of those grand old scientific and objective discussion of race differences would, of course, pipe a different tune – one of outrage! It is the same outrage that you can squeeze out of them by mentioning affirmative action – even though they seem less than outraged that their white American ancestors benefited from affirmative action, otherwise known as the Jim Crow system, for one hundred years after the more oppressive slave system was overthrown.

10

Brett Bellmore 12.01.07 at 2:07 am

I agree that we are witnessing the trivialization of racism. But in the sense that the accusation is coming to be leveled at people who simply aren’t doing anything reprehensible. They’re not advocating discrimination, they’re not prejudiced against individuals, they’re not burning crosses or lynching anybody. They’re simply seriously entertaining ideas that make some people uncomfortable. Uncomfortable, in spite of the fact that the conclusions they draw from these ideas aren’t particularly bad.

This is trivializing racism in the sense that it’s robbing racism of it’s sting; Racism, so stripped of everything offensive, ceases to be anything to be ashamed of.

11

Kieran Healy 12.01.07 at 2:15 am

They’re simply seriously entertaining ideas that make some people uncomfortable.

In this case Brett, they are simply seriously entertaining ideas that are demonstrably unsupported by the evidence, and this makes some people very annoyed.

12

kid bitzer 12.01.07 at 2:21 am

ideas that have been debunked repeatedly; ideas that have been used to support slavery, genocide, apartheid, and a host of atrocities; ideas that almost destroyed this country; ideas that still poison the politics of america to this day.

yeah, weird; i wonder why people get so uncomfortable when brave people treated this thoroughly discredited notions as though they deserve serious consideration.

next up: why can’t i get my synagogue to start a reading group on the protocols of the elders of zion? all i want to do is to seriously entertain some ideas that make some people uncomfortable.

i’m so brave; why are they persecuting me?

13

partiot 12.01.07 at 2:39 am

Listen, I am sick and tired of these gentle responses to racists like Saletan. A bullet to the back of the head would be a measured, reasonable response.

14

Barry 12.01.07 at 3:06 am

In this case Brett, they are simply seriously entertaining ideas that are demonstrably unsupported by the evidence, and this makes some people very annoyed, you lying racist Bell Curvist wh*reson.

Corrected.

15

c.l. ball 12.01.07 at 5:10 am

did he think they would just crawl into his lap and sit there, meowing to be read?

A wonderful metaphor (more evocative if you have a cat).

That said, Brett has a point: it’s a shame no one talks about the nice racists, the ones who care.

16

Brett Bellmore 12.01.07 at 5:11 am

Who could possibly dispute the force of your logic, Barry? The crystalline clarity of it has struck me speechless!

Oh, wait, that’s Henry’s ban, not your logic…

17

Maurice Meilleur 12.01.07 at 1:01 pm

So true, #15. I think it’s a shame we tar the good racists and the bad racists with the same brush. This is so unjust to those racists who use their racism to do good in the world, like fighting for racial harmony and justice.

Oh, yeah, and we apparently also are including uncritically in our condemnations the racists who are too chickensh*t openly to claim the logical conclusions of their premises. Like William Saletan, maybe, and Andrew Sullivan. Or Brett.

18

David Kane 12.01.07 at 1:07 pm

Kieran claims that these “ideas” are “demonstrably unsupported by the evidence.” Good to know! Crooked Timber would contribute much more to scholarly discussion if, instead of ex cathedra pronouncements like that, it hosted, say, a seminar on the topic. Kieren and Henry may think that those on the other side are all blithering idiots, but you won’t catch someone as informed as Shalizi making those sorts of generalizations.

Format? Easy. Start with Jason Malloy’s essay on Watson. Invite whoever you like to comment. (dsquared has thoughts.) Allow Malloy to respond. You can be sure that folks like Razib and others from Gene Expression will chime in. Wide open debate follows. Many views are presented. Science marches forward.

Could this happen at Crooked Timber? I have my doubts. Henry and Kieran already know the truth. Why discus? Someone like John Quiggin seems more open-minded.

Oh, and the question of head/brain sizes is a fun place to start. Facts are stubborn things and all. Pick a thousand people at random of the same race (or different races). Measure their head size using a tape measure or their brain size using an MRI. Give them an IQ test. You think that the correlation between those two vectors will be zero?

No need to look that up! After all, this is probably one of those “ideas” that Kieran has assured us is “demonstrably unsupported by the evidence.”

19

lemuel pitkin 12.01.07 at 2:05 pm

Pick a thousand people at random of the same race (or different races). Measure their head size using a tape measure

Whee! Sounds like someone has a fun summer project al lined up.

20

jdkbrown 12.01.07 at 3:12 pm

I suggest we measure heads in areas where the mortality rate is negative.

21

LizardBreath 12.01.07 at 3:23 pm

Kieren and Henry may think that those on the other side are all blithering idiots, but you won’t catch someone as informed as Shalizi making those sorts of generalizations.

Hasn’t Shalizi just written a series of detailed posts, linked here, explaining his basis for believing the other side are all behaving like blithering idiots? I’m not getting what you want additionally here.

22

Ray 12.01.07 at 3:25 pm

Pick a thousand people at random of the same race (or different races). Measure their head size using a tape measure or their brain size using an MRI. Give them an IQ test. You think that the correlation between those two vectors will be zero?

We should probably find someone good at statistics to work out that last bit.

23

David Kane 12.01.07 at 3:28 pm

LOL!

I know that I should be insulted by jdkbrown, but, that comment had me laughing out loud, as the kids say.

And, by the way, lots more fun stuff coming out about Lancet in the next few months. Stay tuned! For those who care, I also have a partial response to Kieran’s critique from last year. If I ever get around to a full reply, I will pass along the link.

24

Steve 12.01.07 at 3:29 pm

Hasn’t Shalizi just written a series of detailed posts, linked here, explaining his basis for believing the other side are all behaving like blithering idiots? I’m not getting what you want additionally here.

I’m sure David wants to muddy the waters with a series of borderline plausible arguments that he’ll keep setting up as people knock them down, just like he did with his enormously disingenuous (and irresponsible, as it included accusations of academic misconduct) carping about the Lancet Iraq casualty study.

25

s.e. 12.01.07 at 3:35 pm

Watson’s also the schmuck who tramped through a fields of experimental crops developed by a female researcher at Cold Spring, ruing the experiment.
Maybe history should revisit the Rosalind Franklin case again.

26

robertdfeinman 12.01.07 at 4:33 pm

As others have pointed out the unexamined axiom is that there is a valid meaning for “race”.

In the US a great number of the “black” population has some “white” ancestors as well. There was a PBS program about this where well-known people had their DNA tested. The results surprised many of them.

So trying to correlate anything to race is really a variation of the “just one drop” form of racism that has existed in the country for several centuries.

At an earlier time this was the subject of much discussion. There are even two semi-fictional novels on the subject:
“The Marrow of Tradition” by Charles Chesnutt and
“The Autobiography of an Ex-Colored Man” by James Weldon Johnson.

Apparently Krugman’s recent book is timely after all, racism is alive and well in the US as he argues.

27

Kieran Healy 12.01.07 at 4:33 pm

Hasn’t Shalizi just written a series of detailed posts, linked here, explaining his basis for believing the other side are all behaving like blithering idiots? I’m not getting what you want additionally here.

LB, what David Kane wants here is what he always wants, which is to show up as if we don’t already know about his past record, pretend that he’s arguing in good faith, demand that others do his research and analysis for him, and then complain that those others are being unreasonable and dogmatic when they decline to play on the grounds that he has already long ago burned up any credibility he might have had as an interlocutor.

Kieran claims that these “ideas” are “demonstrably unsupported by the evidence.” … Kieren and Henry may think that those on the other side are all blithering idiots, but you won’t catch someone as informed as Shalizi making those sorts of generalizations.

The other thing he does, incidentally, is to ignore qualifying clauses such as “In this case …” in my 11 above. But like I say, we have been here before.

28

cosma 12.01.07 at 4:37 pm

David (@18): the study you propose has (at least) one obvious confounder, which even someone like Vincent Sarich can see pretty plainly. When he did a study that was not so confounded, the correlation between brain size and IQ scores turned out to be trivial. (This was part of my second post on Saletan’s idiocy; for some reason this comment box doesn’t like a direct link to the paper.) As for correlations between brain sizes and ethnic groups, the huge problems there are brought out in another paper I linked to, a link contained in the part of my post Henry quoted above. Kindly follow the links.

The more time I spend on this, the more convinced I become that the race-and-IQ crowd are all blithering idiots; but I admit I have serious intellectual arrogance issues, so that opinion should perhaps be discounted.

29

cosma 12.01.07 at 4:56 pm

15: more evocative if you have a cat

This, comrade ball, is no coincidence.

30

cosma 12.01.07 at 4:59 pm

Kieran (@2): Matt McIrvin recently gave a good description of this phenomenon; what prompted him, I couldn’t say.

31

Bill Gardner 12.01.07 at 5:10 pm

Friends, hear an elder’s wisdom. The same ideas about genes and race come up aqgain and again. The resurgence is never based on new data. It is a troll phenomenon. Competing with each other on who can be more hysterical in denouncing racism (spare me, #13) won’t prevent the next iteration of Jensen/Murray/Saletan. The point has been made, now let’s stop feeding the trolls.

Very occasionally, someone has something new to say (Sandra Scarr back in the day, Flynn, Turkheimer). Otherwise this is all deeply tedious.

32

Kevin Donoghue 12.01.07 at 5:34 pm

Cosma: “The more time I spend on this, the more convinced I become that the race-and-IQ crowd are all blithering idiots….”

Surely that’s part of their charm, indeed part of the reason why you do spend time on this?

I gather from the comments on Matt Y’s thread that one prominent researcher speculates that homosexuality is an infection caught from sheep. Apparently some sheep exhibit behaviour similar to that seen in homo sapiens (excuse the pun). I haven’t got around to reading the paper, so I don’t know whether the author considers the possibility that it was the sheep who caught the infection from men and turned gay as a result.

Hopefully Andrew Sullivan will ensure that this theory is widely publicised, in the interests of science.

33

roger 12.01.07 at 5:51 pm

Brett at 10,

There’s an interesting twist to your representation of Saletan’s project. On the one hand, you represent Saletan as doing nothing reprehensible, but simple advocating an open investigation of IQ differences between races. On the other hand, you seem to want to close off another open investigation, which is the one connecting Saletan’s interest and evident skewing of his data to the legacy and function of institutional racism. I can’t see how you can close off the second investigation unless you are claiming that racism is entirely defined by feeling – thus, if Saletan doesn’t preface his remarks by some statement that he hates black people, then he can’t be a racist. Racism, on this interpretation, is an entirely subjective thing, and we can believe self reporting on it 100 percent.

I don’t buy that. And I think that it is curious that no media outlet ever investigates its own atmosphere and attitudes. Slate might be all too willing to float a series of articles as nutty as Saletan’s (by nutty, I mean that Saletan is evidently so unfamiliar with ‘race science’ that he had never heard of Rushton before – which is a little like publishing a study of WWII and admitting never to have heard of, say, Himmler before. He merely had to go into Slate’s own archives to find salient information). This is from a piece on “How to Deal with Fringe Academics in 2000:

“But MacDonald! It’s not as if all he ever did to link himself up with neo-Nazis was testify a week ago Monday at the David Irving trial. (By the way, John, while on the stand he cited his executive positions at HBES as proof, in part, of his solid professional standing in the field.) MacDonald has created a body of work in which he advances several ideas barely distinguishable from those used not long ago to justify the mass murder of the Jews. In that work, he claims to be building on the ideas of respected scholars. His work has been recognized by many in the scholarly establishment, such as David Sloan Wilson and MacDonald’s editor, Seymour Itzkoff. (Of course, MacDonald also thanks in his acknowledgments other fringe scholars, such as J. Phillippe Rushton, the Canadian who believes that brain size correlates to intelligence.)”

Here would be bravery indeed – what, for instance, is the effect on the hiring practices at the Atlantic magazine of the fact that two of their most prominent contributors, Andrew Sullivan and Ross Douthat, think that it is scientifically proven that blacks are mentally inferior to whites? Now of course you might claim that Sullivan and Douthat are model laboratory workers, objective to the max, simply jotting down the data and coming to fearless conclusions. I don’t know. If I was told that the person I was working with had objectively come to the conclusion that cannibalism is a healthy and necessary adjunct of the human diet, I’d be a little leery of working around him when nobody else was in the office late at night. Humans have the darndest nack for extrapolating rational beliefs onto human behaviors.

So here’s a challenge for brave, contrarian Slate: an article exploring the possibility, mind you, that Slate is institutionally bigoted, starting with Saletan, going through the editing process, looking at the network of writers that are normally contracted to do pieces there, and going through the hiring policy. Maybe they could get David Kane to make an alternate study of the ratio between head size and racism quotient. Xenophobia might be a genetically determined trait!

34

dsquared 12.01.07 at 5:59 pm

Crooked Timber would contribute much more to scholarly discussion if, instead of ex cathedra pronouncements like that, it hosted, say, a seminar on the topic

As with the late Calvin Coolidge’s ability to help a party swing, Kane, you could contribute much to scholarly discussion simply by leaving it.

35

cw 12.01.07 at 6:47 pm

This is my new theory on this issue. I already posted this at MY, but since it is such a great theory I am posting it here too so that you too can benefit from my wisdom.

I think we have to look at the race/IQ phenomena in terms of political ideology.

I think a certain type of conservative mind likes the idea of races with differing abilites. It means that the current state of the world is the result of genetics, that the competition amongst the races has been fair. This absolves a lot past wrongs. It is an anwer to all that liberal poitical correctness. It justifies their position of privilegde. (That these conservatives are also restating ALL the arguments (including penis size and uncontrlled sexuality) that the white man made during the colonialist era to justify the taking of all the goodies, is something I find kind of disturbing. But that’s another topic).

So becasue of this, certain types of conservative minds get really interested in proving this thesis. They spend all their time on it. It bocomes an advocation. The problem is they bring thier biases into a field that is hugely ripe for bias mistakes. The design of cross cultural ability tests, the design of human studies, the interpretation of statistics, all are areas that historically have had a high number of bias mistakes. So they go into these studies with a bias and they find what they are looking for and then– with a telling lack of scientific discipline, they make all kinds of unwarrented extrapolations, hypothosis, guesses, bets.

This could also be true on the liberal side.

The point is, that not only is the science very ambiguous, complicated, and greatly supceptable to bias mistkes, we also have to deal with the effects of political ideology and human nature. A wise person would refrain from making statements about race and IQ either way at this point.

36

Rickm 12.01.07 at 6:53 pm

CW-

Or, if one felt like deviating from the unbearably boring ‘pox on both your houses’ viewpoint, one could simply point out that all the scientists doing this type of work are hacks, that their studies are deeply flawed and quickly rebutted, and that for hundreds and hundreds of years white people have attempted to prove their innate superiority over dark people, and have yet to present a shred of credible evidence. I’d said they had their chance.

37

David Kane 12.01.07 at 7:41 pm

I am sorry that Kieran does not believe that I argue in good faith. Is there anyone who disagrees with him on the topic of either Lancet/Iraq or IQ/Race who, in his opinion, does argue in good faith? If he gives me some specific examples, then perhaps I can improve my behavior. But, my suspicion is that, at least on these issues, there is perfect union of the two sets: those-that-disagree-with-Kieran and those-that-argue-in-bad-faith. Counter examples welcome.

38

baa 12.01.07 at 7:46 pm

Hasn’t Shalizi just written a series of detailed posts, linked here, explaining his basis for believing the other side are all behaving like blithering idiots? I’m not getting what you want additionally here.

I think a back-and-forth with critics would be very illuminating. At least it would be to me. One main thrust of Shalizi’s post on heritability (and I should say here that there is much in that very good post) is that performing estimates of heritability is exceptionally challenging. This is true for IQ as much as for any complex trait. This seems true enough. Yet, if one looks in the literature, one will find people doing heritability estimates for complex traits. Most of these studies have nothing to do with IQ, and still less to do with the race and IQ issues that make the topic so radioactive. It’s not my field, but I’d like to know what a defender of heritability estimates would say, and what that back and forth sounds like.

The discussion on cato unbound between Flynn et al. may not be a perfect model, but it’s pretty useful. It’s also interesting that neither Flynn nor Ceci believe their opponents are idiots, blithering or otherwise.

39

LizardBreath 12.01.07 at 8:03 pm

One main thrust of Shalizi’s post on heritability (and I should say here that there is much in that very good post) is that performing estimates of heritability is exceptionally challenging.

I am very, very far from being an expert or even reasonably fluent in these issues, so someone should correct me to the extent the following is garbled. But I think the point is something much more like that linking estimates of heritability to a vernacular conception of what percentage of some personal quality is genetically determined and therefore unchangeable is not just difficult, in the sense of being hard to measure, but not conceptually reasonable. The number of fingers on your hands is, in that vernacular conception, almost entirely genetically determined. But over a population, the heritability of that number is going to be very low — almost all the variation in number of fingers is going to be environmental (chainsaw accidents) rather than having anything to do with the number of fingers your parents had.

40

LizardBreath 12.01.07 at 8:19 pm

Whoops, I left that unfinished. The upshot, therefore, is not that ‘heritability’ of IQ is necessarily impossible to determine, but that statistical measures of ‘heritability’ in a given population don’t tell us anything at all toward answering the question we’re interested in — to what extent is IQ immune to environmental influences? Heritability doesn’t answer that question for you, not even poorly or incompletely.

41

baa 12.01.07 at 8:20 pm

That’s exactly the type of issue I’d like to hear back and forth on. How should Joe Layman like myself interpret the estimates from the Intelligence: Knowns and Unknowns report?

42

Seth Finkelstein 12.01.07 at 8:22 pm

“Amusingly”, you could probably find clusters of environmental variation of number-of-fingers that passed statistical tests for heritability – as in, if someone works in an industry where accidents are common, there’s a significant probability their parents or other members of their family also do.

One could then proclaim that finger-loss must be heavily genetic, so stringent workplace safety regulations are liberals unwilling to face the hard truths of life.

43

Russell L. Carter 12.01.07 at 8:25 pm

So I follows me the link open minded baa kindly supplies and what with all that important back and forth I end up here (scroll down to the concluding paragraphs):

Take, for example, health care. Patients differ enormously in intelligence level, and these differences have life and death consequences for them. Individuals of lower health literacy, or IQ, are less likely to seek preventive care even when it is free, use curative care effectively when they get it, understand and adhere to treatment regimens, or avoid health-damaging behavior. They have worse health, more accidental injuries, higher health costs, and die sooner—regardless of income, insurance coverage, or quality of health care. Health care matters, as do material resources and motivation, but mental resources matter too. They are critical in the prevention and self-management of chronic illnesses such as diabetes and heart disease. Health self-care is an increasingly complex life-long job for all of us, which becomes even more complex as we age and experience more health problems.

It overstates only slightly to say that health care providers currently pay no attention to patient differences in the ability to learn and understand. As health literacy researchers have shown, however, a sizeable fraction of patients in urban hospital outpatient clinics are unable to understand an appointment slip (when to come back), a label indicating how to take four pills a day, or, among their insulin-dependent diabetic patients, the signs of low (or high) sugar and what action to take to bring their blood sugar back under control. Do proportionately more blacks have such problems? Yes, many more. Is that a reason to continue ignoring or disputing individual and group differences in g?

Takes the concept of driving-while-black to a whole nutha level. Gosh, ya think the concept could have some general application? Think of the possibilities!

Because everyone knows only black people are stupid and it’s a good thing stupid people are black because how would you know a white person was stupid if it was possible for a white person to be stupid? Now I just have to figure what to do with those darn oversmart yellow people.

44

Walt 12.01.07 at 8:28 pm

Baa: Cosma links to two papers that provide detailed summaries of the existing literature. They are written as replies to papers that advance the genetic-race-IQ hypothesis, so you can read the original papers as well. I read through some of the literature in the wake of Saletan’s article, and I was astonished at exactly how weak the evidence for the genetic race-IQ connection was.

45

Russell L. Carter 12.01.07 at 8:30 pm

GRRRRRR! The preview showed both paragraphs as blockquoted! I swear it did. Anyway, the excerpt is both paragraphs (ending with “…diferences in g”, in case it’s not clear. My Original Racist Yahoo Content should be discernable, I hope.

46

LizardBreath 12.01.07 at 8:34 pm

41: Well, one place to start is to note that Shalizi’s argument about ‘heritability’ — not so much that it’s immeasurable, but that it’s not a valid descriptor of ‘the degree to which IQ is immutable’, which is how people tend to use it, is conventional among those arguing that there is no good data tending to establish that group differences in measured average IQ are genetically caused and immutable. Again, I’m no expert, but in a fair amount of lay reading on the subject, I’ve seen various forms of the same argument made convincingly.

You could, on your own, try to follow that argument (Shalizi’s got his IQ posts collected on his site under that tag), and then go looking for refutations that would explain why people who rely on the equation of heritability with immutability don’t accept its validity.

47

cosma 12.01.07 at 8:43 pm

baa @ 41: The 1995 APA report is not, sadly, all that reliable. One the subject of test bias, it repeats a common, but definitely fallacious, argument. On heritability, it pulls together numbers from studies which used the common models, whose assumptions are just wacky, e.g., assuming that the fact that twins spend nine months together in utero has no effect. (No, really.) So my advice would be that Joe Layman is better off ignoring that report, as well-intentioned but technically weak, than attempting to sort through it.

You’re quite right that the problems of trying to estimate heritability are not confined to IQ. Things are a bit better when one is interested in the effects of specific genes, but even then there are huge issues with population structure, and checking that the models are right, which are usually just ignored, if they are even grasped. There are few substitutes for controlled breeding and rearing experiments, or (better yet) being able to actually modify the organisms’ genes and see how that alters developmental mechanisms.

48

cosma 12.01.07 at 8:54 pm

I should add that there is a single value for the heritability of any trait only if some quite strict assumptions hold; otherwise, the fraction of variance in the trait associated with genetic differences will depend on other variables, even within a single population. Turkheimer and co., for example, fitted a model where a (very crude) measure of socio-economic status was allowed to modify the effects of genetic inputs and family environment, and found that the effective heritability of IQ was next to zero at low status, rising to about 0.8 at high statuses. So you should be extremely suspicious of anyone who tries to tell you that the heritability of IQ has any particular value. (And, of course, similarly for other traits.)

49

baa 12.01.07 at 9:26 pm

These comments — and thanks very much to LB, walt, and cosma — are exactly the types of things I would like to see illuminated by a back and forth.

To LB’s point, I can, of course, go to the papers
and try to piece the argument together. I don’t want to that. One reason is because I’m lazy. But a second, more creditable reason is that in my experience a person not steeped in a literature or discipline does himself no favors if he tries to get to the bottom of contentious issues via direct analysis. Sometimes it works out, but it’s just as easy to fixate on the wrong aspects of problems, solve the wrong equations, overlook the totality of evidence, etc. I could read the literature and pose criticisms of the twin studies, or criticisms of the criticism, ad infinitum. But what I really want is to hear is what, e.g., Stephen Ceci would say in defense of that consensus statement, and how a critic would respond, etc. Often, after a couple of rounds of this, Joe Layman is really in a better position.

50

LizardBreath 12.01.07 at 9:56 pm

49: Well, that’s the beauty of the internet — these things don’t need to be formally set up. Cosma can put up his posts that set forth why he thinks that arguments which that there’s good reason to think that that group differences in measured average IQ are genetically caused and immutable are poorly founded, and then someone who disagrees with them can link and refute. I guess the next step is to find someone you think of as credible in this regard who disagrees, and see if you can convince them to link and refute.

51

baa 12.01.07 at 10:19 pm

50: Sure. But activation energy is key here, hence the value of a set forum, etc.

Also, it would be clarifying to know what points are really at issue. Just as an example, I don’t get the sense that anyone within shouting distance of the mainstream claims IQ is immutable. I do get the sense, by contrast, that many researchers believe that, despite limitations, meaningful conclusions about heritability can be drawn from twin studies. It would be useful (to me, at least) to have a unifying set of questions or subjects for debate. That’s the type of focus the back and forth of blog-talk doesn’t usually do as good a job providing.

52

LizardBreath 12.01.07 at 10:31 pm

I’d say a useful subject for the debate you want would be this from Saletan’s original article:

Tests do show an IQ deficit, not just for Africans relative to Europeans, but for Europeans relative to Asians. Economic and cultural theories have failed to explain most of the pattern, and there’s strong preliminary evidence that part of it is genetic.

That is, the really controversial part of the discussion of IQ is differences in average scores between ethnic groups, and specifically the claim that there is good evidence that those differences are due to genetic differences between the groups. The problem with CT setting up a useful forum on the topic (aside from the fact that neither you nor I hands out assignments to the posters here) is that I don’t know, offhand, and don’t know that the CT posters know either, of reasonable people with relevant subject matter expertise who will defend Saletan’s statement.

53

eudoxis 12.01.07 at 10:35 pm

In summary, “intelligence” can’t be defined, much less measured, genetic variance can’t be differentiated from phenotypic variance, heritability of quantitative traits is impossible to determine and, even when methods for QTL analysis exist, biostatisticians won’t know how to use them.

Let’s hope that environmental influences on “intelligence”, once defined, will be a simple matter to elucidate.

54

jre 12.01.07 at 11:33 pm

Crooked Timber would contribute much more to scholarly discussion if, instead of ex cathedra pronouncements like that, it hosted, say, a seminar on the topic.

Is it possible? Is David Kane really going to venture boldly into a whole new field of incompetence?

Pick a thousand people at random of the same race (or different races). Measure their head size using a tape measure or their brain size using an MRI. Give them an IQ test. You think that the correlation between those two vectors will be zero?

Yes!

I am sorry that Kieran does not believe that I argue in good faith.

Yeah — c’mon, what’s wrong with you guys? Give David Kane a chance.
I, for one, eagerly await Race and IQ: the Case for Fraud.

55

dsquared 12.02.07 at 12:21 am

Pick a thousand people at random of the same race (or different races). Measure their head size using a tape measure or their brain size using an MRI. Give them an IQ test. You think that the correlation between those two vectors will be zero?

I was meaning to mention that the word “vectors” here is being used in a sense which leaves it very much an open question whether Kane knows what it means.

56

Zarquon 12.02.07 at 1:34 am

A 1-dimensional array of numbers such as [20.2 20.5 ...] can be called a vector. DK is not using the word incorrectly.
See http://en.wikipedia.org/wiki/Row_vector
The measurements he talks about would result in two lists of numbers which could be called vectors.
(Not that this makes anything else he says correct)

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David Kane 12.02.07 at 1:44 am

There seems to be some interest in a good-faith back-and-forth, let me do my bit. I’ll address these to Cosma, who I have had useful interactions with over the years, but others should feel free to chime in (even dsquared, who seems much less his usual happy warrior self lately).

Cosma,

1) Thanks for your response. You think that Razib and friends are “blithering idiots”? Just want to clarify . . . I think one of the most helpful services you can provide is to indicate those on the other “side” who are most worth reading.

2) I am making an empirical claim. Take a 1,000 random people (all Japanese from Tokyo or whites from Salt Lake City or the first 1,000 you meet walking down the street in NYC). Measure their brain size with an MRI. Give them an IQ test. Are those two vectors correlated? (dsquared should feel free to chime in with his words of wisdom on “vectors.”)

I am no expert in this literature, but I am pretty sure that the answer is Yes. (And I don’t mind trying to bait the CT crowd (i.e., jre in 54) into asserting that it is No.) Now, nothing in particular follows from this empirical fact, but science starts with observations of the world around us. If we can’t first agree on the facts as they are, we aren’t going to make much progress.

This fact, if true, does not imply that IQ tests (or MRIs) are useful or the correlation between the two is real or spurious or genetic. But it often seems to me that small, concrete facts are the place to start the conversation.

Why start here? Cosma mentions the “issue of head sizes.” Is this one of the things that Cosma disputes or not? (Again, this has no necessary connection to race.)

The other reason I start here is that, I think, Cosma is wrong to insist that family is a “confounder” in studies of the relationship between brain size and IQ. I disagree. Consider the relationship between height and basketball success. There is no doubt that this is correlated. Pick a thousand people at random. The taller are more likely to exhibit basketball success (whether because of genes or environment is irrelevant).

But, if we follow the suggestion of the article that Cosma links to, then we would “control” for family by only looking at the, say, sibling pairs. Given two siblings, is the taller always the better basketball player? No! (Or at least, a zero correlation wouldn’t surprise me.) If that isn’t obvious, I would be happy to walk through why. Short answer: most of the variation in height associated with basketball skill is between families, not within them.

Similarly, most of the variation in brain size associated with IQ is between families, not within them.

If CT were to host a forum, it could also start with Cosma essays (rather than Malloy’s). I suspect that I could round about some Gene Expression people to reply.

But, again, that might be a little too wide-open a discussion for the likes of Henry, Kieran and dsquared. I bet that Cosma would be up for it though.

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John Emerson 12.02.07 at 1:47 am

So anyway, what is Kane’s status at at IQSS? Google tells me that he’s got a Harvard Political Economy PhD and is an Institute Fellow at IQSS, and that he is “chairing a panel on mortality in Iraq and the Lancet surveys for the August 2008 Joint Statistical Meetings [of the American Statistical Association] in Denver, Colorado.”

As an Institute Fellow he seems to need an IQSS sponsor and not much more. What does he need to chair at the ASA Joint Statistical Meetings?

I say this because I think that Kane’s credentials and affiliations make it seem that maybe he knows what he’s doing. If he doesn’t, it would seem that IQSS and the ASA might want to do something about it. He drags their name into arguments, and by now it would seem that they should either back him or disavow him.

I have no credentials at all, but I don’t claim them and don’t present myself as a technical expert the way Kane does. At this point Kane’s affiliations and credentials are all that he has as far as I’m concerned.

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David Kane 12.02.07 at 3:41 am

Well done, John Emerson. I sometimes make fun of CT for being the Little Green Footballs of the academic left. You are upholding that fine tradition. Think the comparison with LGF is unfair? Check out comment 13. Nothing like a “bullet to the back of the head” to encourage open-minded discussion.

By the way, has anyone read the article in an anthropology journal that Cosma links to above? (Nothing wrong with anthropologists of course! I just generally look to neuroscientists and psychologists when I am interested in things like brain mass and IQ. Maybe that’s just me!)

Anyway, skim the article. Read Rushton’s reply and then the author’s response. Good stuff!

For the record, I am not a fan of Rushton or of this IQ/race stuff. But I am a believer in IQ and genetics. Tall people have tall children and smart people have smart children, on average. Don’t believe me? Let’s discuss!

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John Emerson 12.02.07 at 4:21 am

Glad to hear from you, David! For me, the only scraps of credibility you have are your affiliations with IQSS and the ASA and your Harvard degree.

The title “Fellow” doesn’t always amount to anything, and I don’t know anything about IQSS or about the APA’s standards for vetting panelists. But if these are reputable organizations with high standards, you gain credibility. On the other hand, if you’re a fraud and a troll, as many have suggested, then these groups lose credibility. So which is it? What do those organizations have to say about the quality your work on the Lancet study? It strikes me that both you and they have an interest in settling this question.

I do not understand medicine and must trust my doctor, and furthermore must rely on accreditation organizations to tell me if a doctor is competent and honest, and in the same way I don’t understand statistics and depend on IQSS and the APA to assure me that you’re competent and honest. But my informal sources, D^2 and others here, assure me that you’re not competent and honest. SO I’d like to know what the ASA and the IQSS have to say. I don’t see how you have a problem with this. Do you regard it as snitching for us to ask your sponsors whether they stand behind your work? Do you think of the ASA and IQSS as cops?

At this point, I have to think one of two things. 1.) Either you or D^2 is incompetent or a fraud. Or 2.) statistics isn’t an exact technical science at all, but just a form of expert advocacy like law, where interested parties do what they can to to get the results they want within rules which are by no means strict. I do not think that your sponsoring organizations would be happy with the latter conclusion, so I think that it’s in their interest to decide whether they endorse your work or not. And in fact, it’s in your interest for them to say that yes, they do indeed endorse your work.

What’s LGFish about that?

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David Kane 12.02.07 at 4:44 am

1) ASA and Harvard have contact information on their websites. Feel free to call them.

2) I do not think that the only two options are that either dsquared or I are dishonest and incompetent. I certainly don’t think that dsquared is. And, I hope, when he’s feeling less emotional, he would grant the same to me. People of good faith disagree all the time, on scientific and other matters.

3) And, to repeat myself, the way to make progress on these sorts of disputes is to talk about them. If Crooked Timber doesn’t want to host such a forum, then that probably should tell you something. If they don’t want to host it, I would be happy to. Or pick another forum.

4) I think that the central problem here is the Cosma’s posts (especially on heritability and g) are 95% perfectly correct. His only “mistakes” — meaning things I think are wrong (and which weren’t even mentioned in those posts) — have been to more recently claim (implicitly, at least) that IQ and brain size have nothing to do with another. That’s just wrong. (Now, again, nothing about race/IQ necessarily follows from that, but we need to start with the facts.) But, the problem with Cosma’s posts is that, while 95%+ true, they are not responsive to the claims made by people like Malloy. But folks not steeped in the details don’t see that. They think that Cosma has refuted Malloy (and others) when, in fact, he hasn’t even engaged them. (I don’t know whether Cosma would agree or disagree with that claim.)

It’s as if Cosma came along and wrote 20,000 words proving that the sky is blue. Indeed, the sky is blue! But that tells you little about IQ and genetics and, especially, race.

By focusing on a small but specific part of the debate — i.e., is brain size correlated with IQ? — I am trying to cajole the two sides (or at least the CT side) to engage in the debate rather than whistling a Shalizi tune as they stroll on past the graveyard of their preconceptions. Wish me luck!

5) I understand that you may not understand statistics. No worries. That is another reason for focusing a specific data rather than principal factors. Are people with big brains smarter? Let’s start there.

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John Emerson 12.02.07 at 4:49 am

I do not think that the only two options are that either dsquared or I are dishonest and incompetent. I certainly don’t think that dsquared is.

During the Lancet debates, especially (a more significant debate than this one, in my opinion), you were repeatedly accused of mishandling statistics (especially by D^2, IIRC). This was not an emotional one-time thing on his part. It seems pretty clear than someone has to be wrong.

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Walt 12.02.07 at 4:59 am

Incompetence is a strong word, David, but it’s clear from the Lancet argument that you don’t understand frequentist statistics. You wasted the time of a lot of people who tried to explain to you what you didn’t understand, when finally it dawned on people that understanding was not high on your list of priorites where Roberts, et al is concerned.

On the big brains question, one of Cosma’s links addresses it. In the nineteenth century, it was observed that “Mongoloid” heads were smaller than Caucasian heads. In the twentieth century, this correlation has reversed. Correlation itself is a very weak argument for causality (I’m sure that the correlation across time between the average IQ and the current world record in the 50 meter dash is pretty respectable). The one study that tried to measure direct causation (I forgot how they did this exactly) found no causation.

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David Kane 12.02.07 at 5:11 am

Two replies:

John: During the Lancet debates, dsquared claimed that the confidence intervals for the crude mortality rates estimates were bootstrapped. He made this claim repeated and vociferously. He was wrong. (Don’t recall if he ever acknowledged that error or thanked me for pointing it out.) Does that make him incompetent or dishonest? No! He just made a mistake. I made several myself. (The next draft of my paper will have those corrected.) That’s how science moves forward.

Walt: I have explained above why Cosma’s citation to a within-family lack of an IQ-brain size correlation is unresponsive. I have suggested that you read (or at least skim) the second paper that Cosma’s links to but then read closely Rushton’s reply and the author’s (pathetic) response. If you don’t think that Rushton clearly wins on the issue of an IQ-brain size correlation (ignoring the race stuff) then we can get into the details. But, on that point, Rushton seems obviously right to me.

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rrp 12.02.07 at 5:16 am

@61 Malloy contends that IQ scores in sub-Saharan Africa are lower.

Shalizi (among others) have shown the problems with measuring intelligence by means of these tests.

The rest of Malloy’s work on the gene expression page seems to be rants about the unwillingness of people to accept the reality of races and not a little shrieking about political correctness (Larry Summer’s name was invoked). Neither of these issues are in any way germane to Shalizi’z excellent work dissecting Saletan, et al.

I was not around for the Lancet Study interchanges, so I don’t fully comprehend the history, but it’s far from clear what you’re trying to do here Mr. Kane. There’s no good science on correlations between brain size and intelligence (and yes, you would expect an anthropologist to weigh in on this, as measuring skulls has long been part of their discipline). But if you want the neuroscientist’s take on it.

Any program that seeks to relate brain weight, cranial capacity, or some other measure of overall brain size to individual performance ignores the reality of the brain’s functional diversity. Thus, quite apart from the political or ethical probity of attempts to measure “intelligence” by brain size, by the yardstick of modern neuroscience (or simple common sense), this approach will inevitably generate more heat than light. A more rational approach to the issue, which has become feasible in the last few years, is to relate the size of measurable regions of known function (the primary visual cortex, for example) to the corresponding functions (visual performance), as well as to cellular features such as synaptic density and dendritic arborization. These correlations have greater promise for functional validity, and less pretense of judgment and discrimination.

This took me maybe 30 seconds to find.

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Dan S. 12.02.07 at 6:51 am

. If I was told that the person I was working with had objectively come to the conclusion that cannibalism is a healthy and necessary adjunct of the human diet, I’d be a little leery of working around him when nobody else was in the office late at night.

Caucasians – the other white meat.

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dsquared 12.02.07 at 11:44 am

I certainly don’t think that dsquared is. And, I hope, when he’s feeling less emotional, he would grant the same to me

Nevergunnahappen, Kane. You accused good scientists of fraud on the basis of no evidence at all. You played me for a sucker by asking for comments on a paper you’d already distributed (and were apparently planning to put my name on as if I’d refereed it). You continually wasted everyone’s time at Deltoid. And now you’re back, insinuating but failing to back up some cockamamie bullshit about racial inferiority. It takes very little emotional effort for me to continue to dislike you, and given the above, I am likely to consider the 3 calories a day well spent for the forseeable future.

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blah 12.02.07 at 12:29 pm

David Kane happens to be right about the correlation between MRI measured brain size and IQ. The correlation improves as you move from measuring the gross volume of the brain to recording volumetric measurements of individual brain compartments (now possible with high resolution MRI).

There is a rapidly expanding literature on the topic by now, but here are a few representative cites.

Haier et al., reviewed in Nature:
http://www.nature.com/news/2004/040721/full/news040719-11.html

The researchers divided the brain into sections and imaged the amount of grey matter in each one. Grey matter is a diffuse network of brain regions thought to be involved in information processing. It is rich in nerve cell bodies and looks grey to the naked eye.

They found that people with high IQ scores had significantly more grey matter in 24 of the regions than people with lower scores. Many of the areas, which are spread throughout the brain, are known to be related to memory, attention and language. Their results are reported online in Neuroimage 1.

Haier believes that different aspects of intelligence might depend on the amount of grey matter in these different brain regions. “This may be why one person is quite good at mathematics and not so good at spelling, and another person, with the same IQ, has the opposite pattern of abilities,” he says.

Nature Reviews Neuroscience 2004

http://www.loni.ucla.edu/~thompson/PDF/nrn0604-GrayThompson.pdf

Neurobiological determinants of intelligence as measured by IQ:

1. Posterior lesions often cause substantial decreases in IQ. Duncan and colleagues suggested that the frontal lobes are involved more in Gf and goal-directed behaviour than in Gc (Fig. 2). In addition, Gf is compromised more by damage to the frontal lobes than to posterior lobe…
2. MRI-based studies estimate a moderate correlation between brain size and intelligence of 0.40 to 0.51
3. g was significantly linked to differences in the volume of frontal grey matter, which were determined primarily by genetic factors… the volume of frontal grey matter had additional predictive validity for g even after the predictive effect of total brain volume was factored out
4. Only one region is consistently activated during three different intelligence tasks when compared to control tasks…The surface features of the tasks differed (spatial, verbal, circles) but all were moderately strong predictors of g (g LOADING; range of r, 0.55–0.67), whereas control tasks were weaker predictors of g (range of r, 0.37–0.41). Neural activity in several areas, measured by a positron emission tomography (PET) scan, was greater during high-g than low-g tasks.
5. Speed and reliability of neural transmission are related to higher intelligence (reviewed in Refs 15,20). Early neuroimaging studies using PET found that intelligence correlated negatively with cerebral glucose metabolism during mental activity54 (for a review, see Ref. 55), leading to the formulation of a ‘neural efficiency’ hypothesis…
6. Gf is mediated by neural mechanisms that support the executive control of attention during working memory…greater event-related neural activity in many regions, including the frontal, parietal and temporal lobes, dorsal anterior cingulate and lateral cerebellum. Crucially, these patterns were most distinct during high-interference trials, even after controlling for behavioural performance and for activity on low-interference trials within the same regions
7. RAPM scores obtained outside the scanner predicted brain activity in a single left parietal/temporal region, and not in the frontal lobes.
8. An exploratory fMRI study60 (n = 7) indicated that parietal areas are involved in inspection time tasks, specifically Brodmann area (BA) 40 and the ventrolateral prefrontal cortex (BA47) but not the dorsolateral prefrontal cortex

Behavioral Genetics of IQ:

1. Monozygotic twins raised separately following adoption show a correlation of 0.72 for intelligence
2. For 48 identical twin pairs separated in early infancy and reared apart, Bouchard et al.83 found remarkably high between-twin correlations for verbal scores on the WAIS (0.64) and for the first principal component of special mental abilities (0.78)
3. Psychometric g has been shown to be highly heritable in many studies, even more so than specific cognitive abilities (h2 = 0.62, Ref. 87 compare with Ref. 88; h2 = 0.48, Ref. 89; h2 = 0.6–0.8, Refs 90,91)…
4. Intriguingly, the influence of shared family environments on IQ dissipates once children leave home — between adult adoptive relatives, there is a correlation of IQ of -0.01

Molecular Genetics of IQ:

1. Chorney et al.104 discovered an allelic variation in a gene on chromosome 6, which codes for an insulin-like growth factor-2 receptor (IGF2R), that was linked with high intelligence…
2. Later studies identified a second IQ-related polymorphism in the IGF2R gene, and others in the cathepsin D (CTSD) gene, in the gene for an acetylcholine receptor (CHRM2)106, and in a HOMEOBOX GENE (MSX1) that is important in brain development107, 108.
3. Influence of each polymorphism was minimal — variants of CHRM2 accounted for a range of only 3–4 IQ points, whereas different forms of CTSD accounted for about 3% of the variation between people…None of these associations has yet been replicated by other research groups
4. Some patients with microcephaly also possess the ASPM mutation, indicating that a shortened version of the gene might lead to the development of fewer cerebral neurons and a smaller head.
5. Polymorphism in the human brain-derived neurotrophic factor (BDNF) gene is associated with impaired performance on memory tests
6. Catechol-O-methyltransferase (COMT) gene influences the activation of working memory circuits. COMT polymorphisms seem to be highly specific to some prefrontal cortex-dependent tasks in children.
7. Dopamine receptor (DRD4) and monoamine oxidase A (MAOA) polymorphisms are associated with differences in performance and brain activity during tasks that involve executive attention

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Maurice Meilleur 12.02.07 at 2:19 pm

I don’t want to rain on the parades of people who think playing statistical whack-a-mole with people like Kane and blah is fun. But the problem is not in the statistics; it’s in the premise of the claims about intelligence and heritability in the first place.

I am a political theorist, not a statistician, but I did study enough statistics in grad school to remember this precept: garbage in, garbage out. Statistical tests of unsound hypotheses are meaningless.

Arguments for the group level and heritability of intelligence all rest on the notion that there is one quality of human beings that we can call intelligence, a quality we can describe precisely enough to make the question ‘who is more intelligent?’ nontrivial and specifiable, and that we can measure precisely enough (the variable ‘g’) that we can compare people and groups of people to one another to see who’s ‘more intelligent’, or that we can correlate with physiological characteristics (genetic potential or expression, fetal development, brain chemistry, or whatever else).

I appreciate that Cosma and others, people with a lot more statistical prowess than I have, can find methodological holes in arguments based on these premeses large enough to drive through. But the better and more fundamental approach would be to ask: what exactly do we mean by ‘intelligence’, and why should we be so invested in its being one thing? Because until you can answer that question, all statistical bets are off.

Speaking only about what I’ve read by people trying to answer this question, and about conversations I’ve had with acquaintances, students, and colleagues about it, here are the two things I find to be true:

1. That there is no way of saying ‘what intelligence is’, certainly not to the extent that statistical tests would require, that is both specifiable and nontrivial. A myriad of qualities and combinations of qualities count as ‘intelligence’. The best I could imagine ever doing is to offer a long list of traits that in that context bear a family resemblance to one another, and that vary in their importance according to their contingent relevance to circumstances and specific problems needing to be solved.

2. That as people who insist against the manifest weakness of their claims that there is such a thing as intelligence understood as it would have to be for ‘g’ to make sense continue to push their arguments, they invariably demonstrate that their conclusion is something they reached independently of and at least in part prior to those arguments. That is, they are not interested really in contemplating intelligence. They are interested to show that intelligence has to be something specific, measurable, and heritable, such that you can say with certainty and the blessings of the NSF that these people over here are intelligent, and these people over here are not, and that’s just the way they are.

This does not mean they are racist, necessarily, though too many of them are. And it is significant that their conclusions about what intelligence is and what groups have it and don’t have it mirror socially-widespread predispositions about both, and involve all sorts of ascription and category errors. (Exactly who, for example, are ‘Asians’? Or ‘African-Americans’?)*

The more I encounter these claims that ‘intelligence’ is best understood as something like ‘g’, and the more I see them rehearsed and renewed in the face of devastating critique, the more certain I am that they are, strictly speaking, bullshit. I mean that in Harry Frankfurt’s sense: they are finally unconcerned with the difference between truth and falsehood, at least as far as their substance is concerned. They are meaningful only in light of the self-image or interests of the claimant, or the intervention in public policy they are meant to advance.

The late Neil Postman had it about right: humans have any number of ways of being intelligent, but they are not nearly as inventive when it comes to ways of being stupid.

* It is also true, by the way, that the conclusions of many people concerned to argue against them are also ones they reached independently of and at least in part prior to their arguments. But the strength of a position does not depend on the intellectual integrity of those who oppose it.

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blah 12.02.07 at 2:22 pm

Also, this link reviews about 20 different studies of MRI measured brain volume vs. IQ. See the third page for citations.

http://books.google.com/books?hl=en&lr=&id=q7ENd_Rnb5UC&oi=fnd&pg=PA93&dq=%22within+family%22+%22brain+size%22&ots=zL8A-Tz4Aj&sig=zka6SaJfzcJN2imJn57req0pqjo

In total 858 people had brain volumes measured by 12 different first authors, with overall weighted regression coefficient around .40.

So the relationship between MRI measured brain volume and IQ is pretty solid.

Note that the 1999 study which Shalizi cites by Schoenemann et al. is included in this analysis. That study is interesting as it found the same .45 between family correlation of IQ vs. brain size, but no *within* family correlation between IQ and brain size.

However, if you note their remarks on pages 4936 of the pdf (http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=18335), they note that the older siblings in their study had on average IQs which were .57 SDs higher than those of the younger siblings — and that the sibling pairs which differed in age by more than 4 years (and hence likely had *less* similar shared environments) had a positive albeit modest relationship (r=.22, P = .054) between WF delta brain volume and WF delta IQ. So it appears that shared environment may be depressing the WF/brain volume correlation.

Additionally, the more recent Gignac et al. article also reports a different data set which *does* show the within family relationship.

Finally, the Schoenemann et al. results are plausibly consistent with a model in which a set of variants which is an upstream determinant of larger brains and higher IQ is inherited together. As a simple model, let F, G, BV, and IQ be random variables representing (1) an index which differs for each family, (2) the number of these variants (assume they are additive and equal for now), (3) MRI measured brain volume, and (4) Raven’s measured IQ.

Then it is quite reasonable to set up a model in which:

1) $P(BV,IQ)$ \neq $P(BV)P(IQ)$
2) $P(G|F)$ is much narrower than $P(G)$ (i.e. the mutual information $I(G;F)$ is quite high relative to the entropy $H(G)$), such that measuring $F$ gives you a good proxy for $G$
3) Finally, $P(BV,IQ|F) \approx P(BV,IQ|G) = P(BV|G)P(IQ|G)$. That is, knowing the family gives you a strong clue about genotype, which in turn turns the BV/IQ relationship to mush.

To visualize this, think about Figure 2a in the Schoenemann paper except add a third axis which goes into the page that measures F, which ranges in this case from 1 to 36.

If F is truly correlated with G, then we have the problem of cryptic stratification, which is a well known bugaboo in the genetics literature; see for example the Pima Indian study or this review (there are lots of more recent ones)

http://cebp.aacrjournals.org/cgi/content/full/11/6/505

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freshlysqueezedcynic 12.02.07 at 2:44 pm

If Crooked Timber doesn’t want to host such a forum, then that probably should tell you something.

Yes, it does. It tells me that the people at Crooked Timber really don’t want to give legitimacy to some racist cranks who really, really want to say “By the way, these blacks are inferior because they’re black”. And really, I feel that is as it should be.

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Brett Bellmore 12.02.07 at 2:51 pm

“and found that the effective heritability of IQ was next to zero at low status, rising to about 0.8 at high statuses.”

More or less what you’d expect if there was a significant genetic component present: It’s the old “hammer blow to the head trumps genes” thing: People of poor socio-economic status provide nurture which varies all over the place, and at it’s worst completely overwhelms any genetic influence, while people of high socio-economic status tend to provide more uniformly good nurture. With the nurture component maxed out, only nature is left to account for differences, so heritablity is high.

But, of course, providing a uniformly positive nurturing environment for children of all socio-economic statuses IS among our goals, isn’t it? So we are, like it or not, aiming to create a world where heritablity of intelligence is very high.

The interesting thing, from my perspective, is that research indicates that bad nurture, in the sense of sub-optimal prenatal nutrition, is the rule, not the exception. Very few potential mothers are gobbling choline and omega 3 fatty acid suplements throughout their fertile years, for instance. Or being chelated to remove heavy metals from their systems.

It seems likely that we could produce a nutritional supplement beverage, based on current research, and provide it at subsidized prices, to huge benefit, and given the facts on the ground, most of that benefit would go to the lower socio-economic groups, particularly blacks. And it wouldn’t be particularly expensive.

I’d suggest that the government not directly produce it, (Bleah!) but instead just provide some kind of subsidy for any beverage which met the requirements. That would probably result in it tasting better, and having a better advertising campaign.

In the mean while, any liberal foundation that felt like actually, you know, doing something to benefit the poor, is capable of doing this on it’s own, and given the economics of scale, private foundations could probably finance the whole thing quite handily.

I now, based on past experience, await being declared a KKK loving racist whore-son for this suggestion. ;)

73

Alex 12.02.07 at 2:54 pm

David, have you ever considered that perhaps you ought to start on some smaller, incremental projects and build up from there? After all, demonstrating that a) you are part of a master race and b) it’s possible to bomb the hell out of a country, invade it, and then have a civil war without killing anyone are some pretty hefty propositions. Couldn’t you turn to, say, improving teaching at IQSS, or something?

74

SG 12.02.07 at 3:15 pm

Alex, your project b) is actually pretty easy compared to project b*): bomb a country and in so doing resurrect the dead, which is what David Kane aims to prove with his crazy fun statistical arguments. It’s only a small step from there to completing project a*): showing that black people have negative IQs.

It’s all the rage at Harvard these days, don’t you know?

75

cosma 12.02.07 at 3:18 pm

No, David, I would not be game for that sort of debate. I try not to do things which implicitly legitimize blithering idiots with pernicious views, and on this and related topics that’s exactly what the GNXP crew are. Malloy’s essay definitely falls into this category. (No, I am not going to write a point-by-point rebuttal.) On a much higher intellectual level, Richard Herrnstein was a real scientist, whose work on the “matching law” was a real contribution to behavioral learning theory; at the same time, in these matters he was a destructive blithering idiot.

Now, as for whether brain volume is correlated with IQ, there are a number of studies which claim this for various samples; the reported correlation coefficients range from slightly negative to around 0.6. Lieberman, in the paper from Current Anthropology I linked to, gives a value of 0.24 from averaging various then-published studies. Averaging correlation coefficients like that is painful to watch, but that’s the kind of statistics Rushton does, so, like Lieberman says, take it up with him. (Incidentally: David, meet the science of physical anthropology; physical anthropology, meet David Kane; the two of you are going to get on like a house on fire, I just know it.) None of them seem to use especially large or especially well-designed samples, but I nonetheless would not be terribly surprised, or at all troubled, if one found a positive correlation in a representative sample of the general population, as such correlations could arise through a large number of processes.* After all, if I took a representative sample of American cities and towns, I would flabbergasted if I didn’t find a positive correlation between the number of inhabitants employed as investment-fund managers and the number employed as prostitutes.

Coming up with correlated quantities is easy. The interesting question is whether they are spurious, or whether they might indicate some actual causal link between the quantities. I have been taking this as obvious, which I guess left a rhetorical opening to make it seem like I was saying there was no such correlation. If one is actually interested in learning about how the world works, one tries to eliminate confounders. (Surely, David, in your day job you pay attention to whether correlations are spurious or not?) Spend a moment drawing the graphical model for your basketball example, and you’ll see that if being taller really makes you better at playing basketball, then the correlation will still show up in a within-family design. (If you do not know how to manipulate graphical models, start with Pearl’s book on causality.) Some spurious correlations will survive this sort of design (again, draw the graph), but if it disappears under this, then it was spurious. Lo: the correlation between brain size and IQ largely, but not entirely, disappears. Conclusion: the correlation is at least largely spurious. (Similarly, I’d expect the correlation between fund-managers and hookers to mostly go away, once one compared cities of equal size.) Moral: on the interesting question, which is the causal one, Rushton is wrong. So, David, on the basis of what evidence do you think that there is a causal connection between brain size and IQ in modern populations?

In general, this conversation has been going on for a long time. Pretending that we’re all starting from scratch here seems pointless and unprofitable. In particular, pretending that various participants haven’t assembled histories, and that the history of the genes-IQ-and-race crowd has been anything to be proud of, is crazy. In very particular, if you want much more out of me, David, you’re going to have to start paying my consulting rates, with a surcharge for the toxic and tedious nature of the work.

*: The Nature Reviews Neuroscience paper that blah links to above claims that the correlation is at the 0.4 to 0.5 level, in support of which it cites two papers from the early 1990s, and a meta-analysis from Nguyen and McDaniel from 2000. It does not discus the possibility of spurious correlation. The papers from the 1990s don’t either — Schoenemann et al.’s paper came out in 2000. I can’t find Nguyen and McDaniel’s paper, but McDaniel went on to publish (http://dx.doi.org/10.1016/j.intell.2004.11.005) a meta-analysis by himself in Intelligence in 2005 . (For David’s edification, McDaniel is a professor of human resources.) The meta-analytic procedure there is curious to behold — is he even giving more weight to studies with more samples? — but in the end comes out with a value of 0.33. McDaniel tosses Schoenemann et al. study into the pile, without any indication that its point was not to just come up with this correlation coefficient, and without any discussion anywhere, that I could find, of the possibility of confounding, which is to say of whether this correlation (assuming that there even is a single value for it) is anything more than an artifact.

76

SG 12.02.07 at 3:19 pm

Brett can you explain to me how the modern problems which beset the western world are actually a function of IQ? It seems like the fundamentals of modern social health, for example – clean water, public transport, preventing overcrowding, basic hygiene – were all discovered and practiced by people whose IQ was lower today than the supposed gap between black and white IQs. How is this small gap meant to explain the big difference in health and social outcomes between black and white Americans? And how does it explain the relative lack of such differences in other countries (e.g. the UK).

I mean, do you really think Zimbabwe’s problems would be solved if everyone there was on average 15 IQ points smarter? And if so, how can you explain World War 2, which occurred between people who you think are smarter? Or, for that matter, the Iraq war?

Framing this in terms of helping black people seems like concern trolling at its very best, to me…

77

Alex 12.02.07 at 3:34 pm

SG: Yes, that’s a good point. As I remarked at the time, there’s only one way of making more people and it’s more fun than reading David Kane.

What would be interesting, however, would be to reframe the entire project of IQ. What about a stupidity quotient? Intelligence is very difficult to define and highly context-dependent; stupidity seems much easier to recognise programmatically.

Admittedly unsystematic empirical observation appears to suggest that SQ is highly decorrelated with typical indices of social status and attainment, and has essentially no correlation at all with race or ethnicity; stupidity is common in all social groups.

And no-one can deny that the world would be a better place if everyone was 10 points less stupid.

78

Kevin Donoghue 12.02.07 at 3:36 pm

David Kane happens to be right about the correlation between MRI measured brain size and IQ.

Maybe so, but the cortical gyral patterns are determined primarily by non genetic factors. (Or so I’m told. I’ll let Cosma handle the toxic and tedious stuff.) What bugs me is that the implications of the racist model are so hard to square with my everyday experience. The Chinese have bigger heads than the Irish? Are you shitting me?

79

SG 12.02.07 at 3:58 pm

Alex, I think I read your link to that stupidity-filtering software a while back. I think a more sophisticated system needs to be applied to academic work before peer review, but only people with a very low SQ could design it. Such people would surely have heads even bigger than David Kane’s…

Kevin, I’m sure Brett can tell you that the cortical gyral patterns create a signature pattern of lumps on the skull which are very closely correlated with intelligence, and easily read by any suitably trained expert. As a bonus, they predict criminality!

80

Alex 12.02.07 at 5:01 pm

I have some sympathy with the Stupidfilter.org people, but I think their methodology is flawed. Personally, I have a memetic model of stupid; stupid beliefs lead us to stupid actions, as we can see from the well-known phenomenon that individuals’ stupidity changes over time. We are all occasionally stupid; the stupid can cease to be stupid.

It’s the killer memes that do it; I would imagine the stupidity test as being more a collection of statements the subject must agree or disagree with.

81

blah 12.02.07 at 6:07 pm

So, David, on the basis of what evidence do you think that there is a causal connection between brain size and IQ in modern populations?

I hope you won’t mind if I pipe up here!

1) We can’t do truly causal experiments in humans, but we can in mice. Mice have successfully served as models for many neurological systems, including Alzheimer’s, so neurological studies on them are fair game for extrapolation to humans.

http://www.pnas.org/cgi/content/abstract/97/13/7657?ck=nck

Enhanced learning after genetic overexpression of a brain growth protein
Aryeh Routtenberg*, Isabel Cantallopsdagger , Sal Zaffuto, Peter SerranoDagger , and Uk Namgung§

Cresap Neuroscience Laboratory, Departments of Psychology and Neurobiology, Institute for Neuroscience, Northwestern University, 2029 Sheridan Road, Evanston, IL 60208

Edited by James L. McGaugh, University of California, Irvine, CA, and approved April 10, 2000 (received for review February 8, 2000)

Ramón y Cajal proposed 100 years ago that memory formation requires the growth of nerve cell processes. One-half century later, Hebb suggested that growth of presynaptic axons and postsynaptic dendrites consequent to coactivity in these synaptic elements was essential for such information storage. In the past 25 years, candidate growth genes have been implicated in learning processes, but it has not been demonstrated that they in fact enhance them. Here, we show that genetic overexpression of the growth-associated protein GAP-43, the axonal protein kinase C substrate, dramatically enhanced learning and long-term potentiation in transgenic mice. If the overexpressed GAP-43 was mutated by a Ser right-arrow Ala substitution to preclude its phosphorylation by protein kinase C, then no learning enhancement was found. These findings provide evidence that a growth-related gene regulates learning and memory and suggest an unheralded target, the GAP-43 phosphorylation site, for enhancing cognitive ability.

2) Brain size correlates with g across primate species

http://www.pnas.org/cgi/content/abstract/99/7/4436

Social intelligence, innovation, and enhanced brain size in primates
Simon M. Reader* and Kevin N. Laland

Department of Zoology, University of Cambridge, High Street, Madingley, Cambridge CB3 8AA, United Kingdom

Communicated by Paul R. Ehrlich, Stanford University, Stanford, CA, January 24, 2002 (received for review August 23, 2001)

Despite considerable current interest in the evolution of intelligence, the intuitively appealing notion that brain volume and “intelligence” are linked remains untested. Here, we use ecologically relevant measures of cognitive ability, the reported incidence of behavioral innovation, social learning, and tool use, to show that brain size and cognitive capacity are indeed correlated. A comparative analysis of 533 instances of innovation, 445 observations of social learning, and 607 episodes of tool use established that social learning, innovation, and tool use frequencies are positively correlated with species’ relative and absolute “executive” brain volumes, after controlling for phylogeny and research effort. Moreover, innovation and social learning frequencies covary across species, in conflict with the view that there is an evolutionary tradeoff between reliance on individual experience and social cues. These findings provide an empirical link between behavioral innovation, social learning capacities, and brain size in mammals. The ability to learn from others, invent new behaviors, and use tools may have played pivotal roles in primate brain evolution.

http://www.springerlink.com/content/g517026182uhh034/

Primate Intelligence
Handbook of Paleoanthropology

Richard Byrne

Brain size has traditionally been employed as a measurable proxy for species intelligence. Using allometric scaling of brain size relative to body size shows the biological cost suffered from investment in brain tissue. Shifts in diet type are the engine permitting increased investment in brain tissue because higher energy diets allow a larger brain at any given body size. Relative brain size, however, confounds effects of gut size required for particular diets with effects of brain size required for enhanced cognitive function. In contrast, the absolute size of brain parts specialized for particular functions gives evidence of the computational power of those systems. Correlational analyses strongly imply that demands of social complexity, rather than difficulties associated with frugivory or embedded foods, led to evolutionary increase in simian primate brain size. Primate brain expansion has largely involved neocortex, and among living primates, neocortex size predicts frequency of use of tactical deception and of innovative responses. These capacities likely rely on extensive memory for social information, but there is evidence (only) among great apes for understanding how systems work, whether social or technical. Representational understanding may derive from the ability to parse complex behavior, allowing imitative learning of elaborate new skills.

3) Modern MRI studies have moved beyond gross brain size/IQ correlations — that is absolutely established at this point in the field, with 37+ studies (see e.g 12 different groups listed on page 3 of this link) and only one negative result, by Tramo & Gazzaniga. Researchers have moved beyond to measurements of individual cognitive regions. This paper from 2004 and the following recent review by Haier et al (dedicated issue of Behavior and Brain Sciences just a few months ago) goes through a lot of the evidence.

http://today.uci.edu/news/release_detail.asp?key=1187

Human intelligence determined by volume and location of gray matter tissue in brain

Single ‘intelligence center’ in brain unlikely, UCI study also finds

Irvine, Calif. , July 19, 2004

General human intelligence appears to be based on the volume of gray matter tissue in certain regions of the brain, UC Irvine College of Medicine researchers have found in the most comprehensive structural brain-scan study of intelligence to date.

The study also discovered that because these regions related to intelligence are located throughout the brain, a single “intelligence center,” such as the frontal lobe, is unlikely.

Richard Haier, professor of psychology in the Department of Pediatrics and long-time human intelligence researcher, and colleagues at UCI and the University of New Mexico used MRI to obtain structural images of the brain in 47 normal adults who also took standard intelligence quotient tests. The researchers used a technique called voxel-based morphometry to determine gray matter volume throughout the brain which they correlated to IQ scores. Study results appear on the online version of NeuroImage.

Previous research had shown that larger brains are weakly related to higher IQ, but this study is the first to demonstrate that gray matter in specific regions in the brain is more related to IQ than is overall size. Multiple brain areas are related to IQ, the UCI and UNM researchers have found, and various combinations of these areas can similarly account for IQ scores. Therefore, it is likely that a person’s mental strengths and weaknesses depend in large part on the individual pattern of gray matter across his or her brain.

“This may be why one person is quite good at mathematics and not so good at spelling, and another person, with the same IQ, has the opposite pattern of abilities,” Haier said.

And see here, especially Figure 2

http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=1305784

“Is there a biology of intelligence which is characteristic of the normal human nervous system?” Here we review 37 modern
neuroimaging studies in an attempt to address this question posed by Halstead (1947) as he and other icons of the last century
endeavored to understand how brain and behavior are linked through the expression of intelligence and reason. Reviewing studies
from functional (i.e., functional magnetic resonance imaging, positron emission tomography) and structural (i.e., magnetic
resonance spectroscopy, diffusion tensor imaging, voxel-based morphometry) neuroimaging paradigms, we report a striking
consensus suggesting that variations in a distributed network predict individual differences found on intelligence and reasoning
tasks.
We describe this network as the Parieto-Frontal Integration Theory (P-FIT). The P-FIT model includes, by Brodmann areas
(BAs): the dorsolateral prefrontal cortex (BAs 6, 9, 10, 45, 46, 47), the inferior (BAs 39, 40) and superior (BA 7) parietal lobule, the
anterior cingulate (BA 32), and regions within the temporal (BAs 21, 37) and occipital (BAs 18, 19) lobes. White matter regions
(i.e., arcuate fasciculus) are also implicated. The P-FIT is examined in light of findings from human lesion studies, including missile
wounds, frontal lobotomy/leukotomy, temporal lobectomy, and lesions resulting in damage to the language network (e.g., aphasia),
as well as findings from imaging research identifying brain regions under significant genetic control. Overall, we conclude that
modern neuroimaging techniques are beginning to articulate a biology of intelligence. We propose that the P-FIT provides a
parsimonious account for many of the empirical observations, to date, which relate individual differences in intelligence test scores
to variations in brain structure and function. Moreover, the model provides a framework for testing new hypotheses in future
experimental designs.

82

blah 12.02.07 at 6:10 pm

So, David, on the basis of what evidence do you think that there is a causal connection between brain size and IQ in modern populations?

1) We can’t do truly causal experiments in humans, but we can in mice. Mice have successfully served as models for many neurological systems, including Alzheimer’s, so neurological studies on them are fair game for extrapolation to humans.

http://www.pnas.org/cgi/content/abstract/97/13/7657?ck=nck

Enhanced learning after genetic overexpression of a brain growth protein
Aryeh Routtenberg*, Isabel Cantallopsdagger , Sal Zaffuto, Peter SerranoDagger , and Uk Namgung§

Cresap Neuroscience Laboratory, Departments of Psychology and Neurobiology, Institute for Neuroscience, Northwestern University, 2029 Sheridan Road, Evanston, IL 60208

Edited by James L. McGaugh, University of California, Irvine, CA, and approved April 10, 2000 (received for review February 8, 2000)

Ramón y Cajal proposed 100 years ago that memory formation requires the growth of nerve cell processes. One-half century later, Hebb suggested that growth of presynaptic axons and postsynaptic dendrites consequent to coactivity in these synaptic elements was essential for such information storage. In the past 25 years, candidate growth genes have been implicated in learning processes, but it has not been demonstrated that they in fact enhance them. Here, we show that genetic overexpression of the growth-associated protein GAP-43, the axonal protein kinase C substrate, dramatically enhanced learning and long-term potentiation in transgenic mice. If the overexpressed GAP-43 was mutated by a Ser right-arrow Ala substitution to preclude its phosphorylation by protein kinase C, then no learning enhancement was found. These findings provide evidence that a growth-related gene regulates learning and memory and suggest an unheralded target, the GAP-43 phosphorylation site, for enhancing cognitive ability.

2) Brain size correlates with g across primate species

http://www.pnas.org/cgi/content/abstract/99/7/4436

Social intelligence, innovation, and enhanced brain size in primates
Simon M. Reader* and Kevin N. Laland

Department of Zoology, University of Cambridge, High Street, Madingley, Cambridge CB3 8AA, United Kingdom

Communicated by Paul R. Ehrlich, Stanford University, Stanford, CA, January 24, 2002 (received for review August 23, 2001)

Despite considerable current interest in the evolution of intelligence, the intuitively appealing notion that brain volume and “intelligence” are linked remains untested. Here, we use ecologically relevant measures of cognitive ability, the reported incidence of behavioral innovation, social learning, and tool use, to show that brain size and cognitive capacity are indeed correlated. A comparative analysis of 533 instances of innovation, 445 observations of social learning, and 607 episodes of tool use established that social learning, innovation, and tool use frequencies are positively correlated with species’ relative and absolute “executive” brain volumes, after controlling for phylogeny and research effort. Moreover, innovation and social learning frequencies covary across species, in conflict with the view that there is an evolutionary tradeoff between reliance on individual experience and social cues. These findings provide an empirical link between behavioral innovation, social learning capacities, and brain size in mammals. The ability to learn from others, invent new behaviors, and use tools may have played pivotal roles in primate brain evolution.

http://www.springerlink.com/content/g517026182uhh034/

Primate Intelligence
Handbook of Paleoanthropology

Richard Byrne

Brain size has traditionally been employed as a measurable proxy for species intelligence. Using allometric scaling of brain size relative to body size shows the biological cost suffered from investment in brain tissue. Shifts in diet type are the engine permitting increased investment in brain tissue because higher energy diets allow a larger brain at any given body size. Relative brain size, however, confounds effects of gut size required for particular diets with effects of brain size required for enhanced cognitive function. In contrast, the absolute size of brain parts specialized for particular functions gives evidence of the computational power of those systems. Correlational analyses strongly imply that demands of social complexity, rather than difficulties associated with frugivory or embedded foods, led to evolutionary increase in simian primate brain size. Primate brain expansion has largely involved neocortex, and among living primates, neocortex size predicts frequency of use of tactical deception and of innovative responses. These capacities likely rely on extensive memory for social information, but there is evidence (only) among great apes for understanding how systems work, whether social or technical. Representational understanding may derive from the ability to parse complex behavior, allowing imitative learning of elaborate new skills.

3) Modern MRI studies have moved beyond gross brain size/IQ correlations — that is absolutely established at this point in the field, with 37+ studies (see e.g 12 different groups listed on page 3 of this link) and only one negative result, by Tramo & Gazzaniga. Researchers have moved beyond to measurements of individual cognitive regions. This paper from 2004 and the following recent review by Haier et al (dedicated issue of Behavior and Brain Sciences just a few months ago) goes through a lot of the evidence.

http://today.uci.edu/news/release_detail.asp?key=1187

Human intelligence determined by volume and location of gray matter tissue in brain

Single ‘intelligence center’ in brain unlikely, UCI study also finds

Irvine, Calif. , July 19, 2004

General human intelligence appears to be based on the volume of gray matter tissue in certain regions of the brain, UC Irvine College of Medicine researchers have found in the most comprehensive structural brain-scan study of intelligence to date.

The study also discovered that because these regions related to intelligence are located throughout the brain, a single “intelligence center,” such as the frontal lobe, is unlikely.

Richard Haier, professor of psychology in the Department of Pediatrics and long-time human intelligence researcher, and colleagues at UCI and the University of New Mexico used MRI to obtain structural images of the brain in 47 normal adults who also took standard intelligence quotient tests. The researchers used a technique called voxel-based morphometry to determine gray matter volume throughout the brain which they correlated to IQ scores. Study results appear on the online version of NeuroImage.

Previous research had shown that larger brains are weakly related to higher IQ, but this study is the first to demonstrate that gray matter in specific regions in the brain is more related to IQ than is overall size. Multiple brain areas are related to IQ, the UCI and UNM researchers have found, and various combinations of these areas can similarly account for IQ scores. Therefore, it is likely that a person’s mental strengths and weaknesses depend in large part on the individual pattern of gray matter across his or her brain.

“This may be why one person is quite good at mathematics and not so good at spelling, and another person, with the same IQ, has the opposite pattern of abilities,” Haier said.

And see here, especially Figure 2

http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=1305784

“Is there a biology of intelligence which is characteristic of the normal human nervous system?” Here we review 37 modern
neuroimaging studies in an attempt to address this question posed by Halstead (1947) as he and other icons of the last century
endeavored to understand how brain and behavior are linked through the expression of intelligence and reason. Reviewing studies
from functional (i.e., functional magnetic resonance imaging, positron emission tomography) and structural (i.e., magnetic
resonance spectroscopy, diffusion tensor imaging, voxel-based morphometry) neuroimaging paradigms, we report a striking
consensus suggesting that variations in a distributed network predict individual differences found on intelligence and reasoning
tasks.
We describe this network as the Parieto-Frontal Integration Theory (P-FIT). The P-FIT model includes, by Brodmann areas
(BAs): the dorsolateral prefrontal cortex (BAs 6, 9, 10, 45, 46, 47), the inferior (BAs 39, 40) and superior (BA 7) parietal lobule, the
anterior cingulate (BA 32), and regions within the temporal (BAs 21, 37) and occipital (BAs 18, 19) lobes. White matter regions
(i.e., arcuate fasciculus) are also implicated. The P-FIT is examined in light of findings from human lesion studies, including missile
wounds, frontal lobotomy/leukotomy, temporal lobectomy, and lesions resulting in damage to the language network (e.g., aphasia),
as well as findings from imaging research identifying brain regions under significant genetic control. Overall, we conclude that
modern neuroimaging techniques are beginning to articulate a biology of intelligence. We propose that the P-FIT provides a
parsimonious account for many of the empirical observations, to date, which relate individual differences in intelligence test scores
to variations in brain structure and function. Moreover, the model provides a framework for testing new hypotheses in future
experimental designs.

83

Barry 12.02.07 at 6:18 pm

“I now, based on past experience, await being declared a KKK loving racist whore-son for this suggestion. ;)”

Posted by Brett Bellmore

It’s not the stupidest thing that you’ve ever posted here, nor the most evil, nor the most dishonest. Which is pretty back-handed praise on my part, but no less than you deserve.

Brett, let me explain myself – not for you, but for any others who are unaware of your history here.

Brett has repeatedly made a whole boatload of comments on the various ‘race and IQ’ threads. In those many, many comments, he’s posted nothing new, just reheated junk science, and many greasy arguments that he’s not *actually* arguing for the thesis of racial inferiority of blacks. After watching him do this on two or three previous threads, he lost the benefit of the doubt with me.

Brett has also posted lots of dishonest right-wing comments here and on Obidiian wings; he has a history, and does not come into any thread with a clean toga, so to speak.

84

Bill Gardner 12.02.07 at 6:59 pm

there is no way of saying ‘what intelligence is’, certainly not to the extent that statistical tests would require, that is both specifiable and nontrivial.

Be aware that if that were so, you would similarly not be able to conduct statistical tests on variables measuring ‘depression’, ‘health’, ‘quality of life’, or even seemingly more tangible things such as ‘pulmonary function’. The big problem in this research is not semantics or even psychometrics. Whatever IQ tests measure, it would be big news if it were heritable in the way that Rushton, for example, wants to claim. The problem, as I see it, is in the unrealistic assumptions ( = simplistic theory about the role of genes in development) that underlies the standard calculation of heritability.

Strongly recommend that folks read Flynn, Turkheimer, and William Dickens. From Flynn and Dickens

How could solid evidence show both that environment was so feeble (kinship studies) and yet so potent (IQ gains over time)?

Dickens has proposed a model that we believe solves the paradox. It assumes that people who have an advantage for a particular trait will become matched with superior environments for that trait; and that genes can derive a great advantage from this because genetic differences are persistent. A genetic advantage remains with you throughout life, while environmental differences tend to come and go, unless sustained by the steady pressure of genes.

Take those born with genes that make them a bit taller and quicker than average. When they start school, they are likely to be a bit better at basketball. The advantage may be modest but then reciprocal causation between the talent advantage and environment kicks in. Because you are better at basketball, you are likely to enjoy it more and play it more than someone who is bit slow or short or overweight. That makes you better still. Your genetic advantage is upgrading your environment, the amount of time you play and practice, and your enhanced environment in turn upgrades your skill. You are more likely to be picked for your school team and to get professional coaching.

Thanks to genes capitalizing on the powerful multiplying effects of the feedback between talent and environment, a modest genetic advantage has turned into a huge performance advantage. Just as small genetic differences match people with very different environments, so identical genes tend to produce very similar environments—even when children are raised in separate homes.

In other words, kinship studies of basketball, no matter whether they involved people with identical genes or different genes, would underestimate the potency of environmental factors. Playing, practicing, being on a team, coaching, all of these would be credited to genes—simply because differences in them tend to accompany genetic differences between individuals. Genes might seem to account for as much as 75 percent of variance across individuals in basketball performance. If someone showed that the present generation was far more skilled at basketball than the last (as indeed they are), Jensen’s math would prove that it was impossible. It would show that those aspects of environment that are not correlated with genes (which is all that environment gets credit for in kinship studies) were very feeble. So feeble that the present generation would have to be within the top one percent of the last in terms of quality of environment for basketball.

85

Bill Gardner 12.02.07 at 7:01 pm

Sorry that it wasn’t clear, but everything below the link in the post above is actually a quote from Flynn and Dickens summary of their work on the Brookings website.

86

David Kane 12.02.07 at 7:02 pm

1) A while ago in comment time, baa wrote:

I think a back-and-forth with critics would be very illuminating. At least it would be to me.

Alas, you aren’t going to find that at Crooked Timber. If Henry and Kieran and dsquared actually had to confront the scientific literature, as outlined by blah above, their heads would explode. Can’t have that! Better for them to keep to drive-by sniping.

2) I understand Cosma’s desire to avoid this debate. Most days, I feel the same way myself! Indeed, part of my wants to suggest that he should spend less time on this stuff and more time on his academic work. Then again, there is clearly a niche for the super-smart-statistician-who-beats-up-on-guys-like-Rushton in the academic ecosystem. Cosma has a choice. He can either write super long essays that almost all his supporters won’t understand and who will sleep better at night having read them. Or, he can spend the same about of time having an open-forum debate with someone like blah. The choice is his.

3) I only entered this particular debate because Cosma was trying to pull a fast one, and the CT crowd is too eager to believe him. Cosma claimed that “the issue of head sizes” is “crap.” Now, he wisely does not make clear what about head sizes is crap and the CT crowd wanted to believe that it all was. So, I entered the fray with a specific question about the empirical world. Much derision followed. But now, even Cosma (I think) grants that I was correct. If you (or me or Henry or Kieran or dsquarted) walks outside and measures the brain size and IQ of 1,000 random people, those vectors — Still looking forward to your lecture on that topic, dsquared! — will be correlated. Hooray! We have learned something now about the world as it is.

4) And that is, perhaps, all that I have energy for today. Cosma now wants to claim that this correlation — which 90%+ of the CT community was even unaware of, was likely to assume was “crap” on the basis of Cosma’s misleading links — is “spurious.” Perhaps it is! Let’s have a discussion. There is a great deal of peer-reviewed scientific literature relevant to the debate. Shall we dive in?

5) Minor point: Cosma’s recommends Pearl. I am much more a Rubin Causal Model man myself, but to each his own.

6) Cosma writes:

So, David, on the basis of what evidence do you think that there is a causal connection between brain size and IQ in modern populations? … In very particular, if you want much more out of me, David, you’re going to have to start paying my consulting rates, with a surcharge for the toxic and tedious nature of the work.

I’ll make a deal. I don’t have to pay your consulting rates and you don’t have to pay mine!

But, I am happy to answer your questions as long as you like. For all my complaints, I like the CT comment-reading community and am pleased to do my part to education people like baa.

I do not think that it makes much sense to ask about a “causal” connection between brain size and IQ. (See the Rubin Causal Model link above.) I’ll add more on that if you want to read it.

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Alex 12.02.07 at 7:11 pm

For all my complaints, I like the CT comment-reading community and am pleased to do my part to education people like baa.

We’ve made it! The self-satirising comment. What a breakthrough.

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roger 12.02.07 at 7:46 pm

Since Neanderthals had a larger cranial capacity than homo sapiens, and the paleological evidence is that early homo sapiens had a larger cranial capacity than contemporary ones, I guess the IQ renaissance was about 50,000 years ago.

One of the great things about the racist meme of head size as a target for some wierd gene mutation that favored white skins whereever they are is that it is a two-fer – after all, women, being shorter, are going to have a smaller head size too. Great! You can get your racist and your sexist party on!

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dsquared 12.02.07 at 7:53 pm

If Henry and Kieran and dsquared actually had to confront the scientific literature, as outlined by blah above, their heads would explode.

Please consider yourself pre-emptively banned from any thread I post in future, Kane.

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adam 12.02.07 at 8:03 pm

Folks, Saletan is Imus for the middlebrow set. The point of his column is to get page views. To that end he traffics in sex, race, and violence (just read his human nature column!).

While his writing persona is “serious thinker” aka “wanker-tradionalist”, I doubt he had any real intellectual committent to the ideas he was pushing. He just wanted the attention one gets for saying something controversial.

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David Kane 12.02.07 at 8:29 pm

That’s the spirit dsquared! The choir awaits your future sermons.

By the way, perhaps you could outline for other commentators who seek to avoid your wrath what your criteria are for banning. Since I (almost always) avoid foul language and ad hominem, I guess that you must not like, what? The arguments themselves?

Enjoy the echo chamber. Crooked Timber is the Little Green Footballs of the academic left. Not that there is anything wrong with that!

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philosopher 12.02.07 at 8:52 pm

“By the way, perhaps you could outline for other commentators who seek to avoid your wrath what your criteria are for banning. Since I (almost always) avoid foul language and ad hominem…”

That Kane thinks that _these_ are somehow the unpardonable intellectual sins speaks volumes as to just how utterly clueless about real academic discourse he is. How about, e.g., repeatedly mangling other people’s work, and a demonstated commitment to ignoarance about the arguments of one’s interlocutors (both of which are in patent evidence in the snippet of his that dsquared quoted above)?

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Walt 12.02.07 at 9:04 pm

That long comment by David Kane is his arguing style in a microcosm. He picks on some mostly-irrelevant point, construes the comments explaining “that’s irrelevant” or “you’re misunderstanding the statistics” as proving that other people are trying to commit fraud, and then flounces off to pick on some other irrelevant point.

David _always_ ignores the relevant arguments. _Always_. For example, he ignored my 50-meter-dash/average-IQ analogy, because hey, it completely eviscerates his argument. Instead, he tries to twist Cosma’s words into “pulling a fast one”. It’s hard to judge, though. Cosma is clearly talking about cause-and-effect, since lots of variables are correlated with each other without proving much of anything. Does David not understand this, or he is just pretending not to understand it for the purposes of confusing the reader? I had the exact same question after the Lancet brouhaha. Though maybe the correlation between incompetence and malice is over 0.50.

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Kevin Donoghue 12.02.07 at 9:31 pm

David Kane: But now, even Cosma (I think) grants that I was correct.

So what’s the answer to my question? Do the Chinese have bigger heads than the Irish or don’t they?

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baa 12.02.07 at 9:31 pm

I don’t know what offenses against commenting decency David Kane is alleged to have committed in the past. I have found his comments here — along with those of Cosma and blah in particular — quite helpful. So thanks to everyone, and I’m sorry if my requests for more information here furthered bad feeling.

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LizardBreath 12.02.07 at 9:51 pm

blah in particular

Seriously? Blah’s comments look like irrelevant smoke-blowing to me. Could you tell me what you found helpful about them — that is, as a layperson, what you didn’t know or understand before blah’s comment that you now do know or understand?

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baa 12.02.07 at 10:26 pm

Could you tell me what you found helpful about them

Sure, lots of avenues of research of which I wasn’t aware. To take one specific area, it seems like there is more support for (and more work on) connections between brain anatomy and function than I had thought.

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Walt 12.02.07 at 10:28 pm

Baa, were you persuaded by David’s accusations that Cosma was trying to pull a fast one?

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LizardBreath 12.02.07 at 10:32 pm

more support for (and more work on) connections between brain anatomy and function than I had thought.

Okay, I guess if you weren’t aware that the physical structure of the brain and its connection to intellectual function was an active area of research, sure,that would be something you could have picked up from blah’s comments. But he didn’t actually say anything relevant to, say, Saletan’s claims that there was strong preliminary evidence for a genetic component to the differences in average tested IQ scores between various ethnic groups, or if he did, I missed it.

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Henry 12.02.07 at 10:38 pm

David – as you yourself might say, “excellent comments!”:http://scienceblogs.com/deltoid/2007/08/robert_chung_on_david_kane.php. Except that they’re not. Given your track record of dishonesty, blatant hackery &c&c&c, I can’t be arsed putting up with you anymore, and I’m going with dsquared. Consider yourself permanently banned from commenting on my threads.

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John Emerson 12.02.07 at 10:43 pm

Troll motherfuckers always congratulate themselves for avoiding “language” and insults.

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John Emerson 12.02.07 at 10:47 pm

Per David’s query about Robert Chung in the thread Henry linked, can we be sure that “dsquared” is really Daniel Davies? And not some imposter?

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Walt 12.02.07 at 10:48 pm

That’s like saying if we found someone hiding out in Argentina who confessed to being Hitler that they would be lying. No one would admit to being dsquared other than the real article.

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Bill Gardner 12.02.07 at 11:12 pm

baa:

Differences in intellectual performance will correspond to differences in neuroanatomy. I can’t say whether the studies people have cited here have actually found this. But we will eventually find this.

That has nothing to do with whether the causes of those differences in performance or neuroanatomy are innate or environmental.

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blah 12.02.07 at 11:54 pm

But he didn’t actually say anything relevant to, say, Saletan’s claims that there was strong preliminary evidence for a genetic component to the differences in average tested IQ scores between various ethnic groups, or if he did, I missed it.

Hi lizardbreath, I actually was steering well clear of that issue. The post’s focus was only responding to this question:

on the basis of what evidence do you think that there is a causal connection between brain size and IQ in modern populations?

I thought it would be interesting to bring together some recent research of relevance. There is a lot of work now on the specific brain regions correlated with g! Very exciting field, I think!

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jre 12.03.07 at 12:22 am

By the way, perhaps you could outline for other commentators who seek to avoid your wrath what your criteria are for banning.

Hmmm … Well, on the chance that D2 has some better use for his time than explaining himself on this one, how about we let one of the groundlings have a whack?

When you publish a post accusing other researchers of fraud, and your own site’s moderator removes it, saying that “[t]he tone is unacceptable, the facts are shoddy, and the ideas are not endorsed by myself, the other authors on the sidebar, or the Harvard IQSS.”, that’s a clue.

When you publish a technical critique of a mortality study, using the term “CMR” 118 times, and it subsequently turns out that you do not know how to calculate a CMR, that’s another clue. And it retains its cluelessness even if Michelle Malkin thinks that critique is an original and significant contribution to the literature.

When you wade into this thread with a breathtakingly stupid comment about head size and IQ, then receive multiple replies to the effect that Cosma Shalizi’s entire argument has whizzed past you without even ruffling your hair, that is yet another clue.

And when, carrying all this baggage, you have the eye-popping chutzpah to say something like “If Henry and Kieran and dsquared actually had to confront the scientific literature, as outlined by blah above, their heads would explode.”, you have shown yourself to be far beyond clue-resistant; in fact your armor cannot be penetrated by any clue known to the art.

This, I think, is why Henry and Kieran and D2 have lost patience with you. It is not because your every contribution actually subtracts from the discussion (although it does); it is, rather, because you seem to be convinced that every one of your pseudo-insights is Galilean in its heroism, and watching this display is embarrassing to all concerned.

Now, all the above may not be how Henry and Kieran and D2 feel at all — I’m just guessing. Speaking for myself, I’ll admit to a certain perverse hope that Cosma Shalizi will actually spend some time on you. Another clue: restock your Bactine before that happens.

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LizardBreath 12.03.07 at 12:27 am

And of course, the discovery of genetically determined differences in neuroanatomy that correspond to differences in intellectual performance, if such are discovered (which doesn’t seem unlikely), still doesn’t get us anywhere near strong evidence that differences in average tested IQ between ethnic groups correspond to genetically determined differences between members of those ethnic groups.

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Dan S. 12.03.07 at 12:29 am

2) Brain size correlates with g across primate species

This is a very interesting statement.

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jdkbrown 12.03.07 at 12:43 am

I’ll second dan s. How do they get the chimpanzees to sit still long enough to take the tests? Do they have very small pencils for the tarsirs and very large ones for the orangutans? Do the gorillas sign their answers?

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Down and Out of Sài Gòn 12.03.07 at 12:48 am

I didn’t find “blah”‘s comments that helpful. It looks like he cut-and-pasted a couple of abstracts, bold-faced some sentences, and called it a post.

As a few people have indicated – most of us have time constraints. If someone appears unable to distinguish between content which is superfluous, and and content which is not, then I can’t be bothered reading. It’s like a squid squirting ink – a lot of substance intended to obscure.

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Mitchell Young 12.03.07 at 1:35 am

assuming that the fact that twins spend nine months together in utero has no effect.

Twin studies typically study both monozygotic and fraternal twins, thus controlling directly for in utero effects.

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LizardBreath 12.03.07 at 1:36 am

105: Yeah, but you still didn’t say anything relevant to establishing a “causal connection between brain size and IQ in modern [human]populations”; you simply quoted a bunch of extracts from very marginally related papers. If there’s any proposition that you expected a reader to be persuaded of by your comment, I was unable to discern what that proposition might be.

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baa 12.03.07 at 2:27 am

If there’s any proposition that you expected a reader to be persuaded of by your comment, I was unable to discern what that proposition might be.

I don’t want to speak for blah, but my sense was he was trying to support this claim:

David Kane happens to be right about the correlation between MRI measured brain size and IQ.

Which in turn supported this one from Kane:

His only “mistakes”—- meaning things I think are wrong (and which weren’t even mentioned in those posts)—- have been to more recently claim (implicitly, at least) that IQ and brain size have nothing to do with another. That’s just wrong. (Now, again, nothing about race/IQ necessarily follows from that, but we need to start with the facts.)

Certainly, there appears to be more to this hypothesis than I imagined before reading this thread. As you note — and as Kane noted — we can stipulate that there’s a correlation between brain size and IQ and be nowhere near evidence one way or another on the ‘radioactive’ questions.

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LizardBreath 12.03.07 at 3:14 am

Hrm. So the bits about mice and differences in brain size between different primate species weren’t in support of anything particular?

I (again, as a layperson) couldn’t tell you if the purported correlation between brain size and IQ within a population stands up (I don’t see why it wouldn’t, given that there’s a pretty well established correlation between height and IQ). But such a correlation isn’t any more suggestive of a genetic explanation for differences between average IQ test scores among different ethnic groups than the correlation with height is.

Your initial wish that people would pin down what’s actually being argued is a good one. Where the claim being argued is Saletan’s assertion that I quoted in 52, arguments that don’t tend to either support or refute that assertion don’t add much of anything to the discussion.

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Mitchell Young 12.03.07 at 7:42 am

http://cat.inist.fr/?aModele=afficheN&cpsidt=4080169

“The issue of the connection between brain size and intelligence has long been of interest to psychology. A review of past research using external head size measures as estimates of internal brain size indicates that head size-IQ correlations are typically in the order of r = 0,10 to 0.30 (mean r = 0.194). Today, a more direct and accurate measure of brain size is afforded by the advent of magnetic resonance imaging (MRI). In the present study the relationship between brain size (measured via MRI), head size, and intelligence was examined in a sample of 40 healthy, right-handed females (ages 20 to 30 years). Whereas head size correlated r = 0.109 (NS) with full scale IQ, brain size and IQ correlated r = 0.395 (P

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Mitchell Young 12.03.07 at 8:39 am

Put simply, the problem is that any group of quack scholars with a shared delusion can put together a journal, dub each other peer reviewers, and go on their cheerful way by endorsing each others’ work for their journal

But of course the Journal of Psych and Public Policy (the source of Saletan’s article) is published by the APA — not a small group of “quack” scholars. Dr. Shalizi also fails to note the rebuttals to the rebuttal which shows Nisbett’s (in particular) critique to be quite ineffective — relying on studies 30 plus years old. Finally he distinctly downplays Jensen and ignores Gottfried, concentrating his attack on the (admittedly) baggage laden Rushton. Nice rhetorical , or even better ‘heresthetic’ technique (after Riker). But hardly a dispassionate dissection of the evidence.

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Mitchell Young 12.03.07 at 8:41 am

Gottfredson vice Gottfried

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Kevin Donoghue 12.03.07 at 11:04 am

Mitchell,

I don’t think “a sample of 40 healthy, right-handed females” can be regarded as a fair test of David Kane’s claim – which is one of the most outlandish claims I have seen in this area, and that’s saying something. Kane’s contention is that in a random sample of the same race (or different races), measuring head size using a tape measure there will be a positive correlation between head size and IQ.

It doesn’t matter, apparently, if the women with the small heads are Japanese and the men with the big heads are Dutch. In Kane’s model only size matters.

I’ll say this for him – he’s not afraid to look the ghost of Karl Popper in the eye.

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Mitchell Young 12.03.07 at 12:57 pm

I am not addressing David Kane’s claim. I am addressing the general claim, put forward by Prof. Shalizi and others, that there is no or even weak evidence for correlation of brain size and IQ , and that there is no evidence for correlation of IQ with geographically distinct population groups, i.e. races. And that those who study such things are ‘blithering idiots’. There is evidence, read all the Psychology and Public Policy papers, Rushton and Jensen, the critiques, the rebuttals to critiques. Please also note who are the fundamentalists here — the environmentarians. The genetic determinsts are perfectly willing to grant environmental effects have a large part to play in developing IQ.

BTW the use of a group of ‘healthy, right-handed females’ controls for several variables experimentally — the kind of thing that social scientists must do through large sames and statistical methods.

I will admit the ‘within family’ study gives me pause. However, I have my doubts about it — first I couldn’t find an ‘N’ for pairs of siblings in the study. Maybe I am missing it. Second the ‘age corrections’ for brain size seem shakey. The group could be washing out variance right there.

Here is a twin study regarding brain size.[note the comparison of monozygote (MZ -- 'identical') twins and dizygote (DZ-'frateral') twins. That's the control for in utero effects!]

http://www.mitpressjournals.org/doi/abs/10.1162/089892900561850?cookieSet=1&journalCode=jocn

“Although it is well known that there is considerable variation among individuals in the size of the human brain, the etiology of less extreme individual differences in brain size is largely unknown. We present here data from the first large twin sample (N=132 individuals) in which the size of brain structures has been measured. As part of an ongoing project examining the brain correlates of reading disability (RD), whole brain morphometric analyses of structural magnetic response image (MRI) scans were performed on a sample of adolescent twins. Specifically, there were 25 monozygotic (MZ) and 23 dizygotic (DZ) pairs in which at least one member of each pair had RD and 9 MZ and 9 DZ pairs in which neither member had RD. We first factor-analyzed volume data for 13 individual brain structures, comprising all of the neocortex and most of the subcortex. This analysis yielded two factors (“cortical” and “subcortical”) that accounted for 64% of the variance. We next tested whether genetic and environmental influences on brain size variations varied for these two factors or by hemisphere. We computed intraclass correlations within MZ and DZ pairs in each sample for the cortical and subcortical factor scores, for left and right neocortex, and for the total cerebral volume. All five MZ correlations were substantial (r’s=.78 to .98) and significant in both samples, as well as being larger than the corresponding DZ correlations, (r’s=0.32 to 0.65) in both samples. The MZ-DZ difference was significant for 3 variables in the RD sample and for one variable in the smaller control sample. These results indicate significant genetic influences on these variables. The magnitude of genetic influence did not vary markedly either for the 2 factors or the 2 hemispheres. There was also a positive correlation between brain size and full-scale IQ, consistent with the results of earlier studies. The total cerebral volume was moderately correlated (r=.42, p

120

Alex 12.03.07 at 1:16 pm

You are Brett or David and I claim my prize.

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Kevin Donoghue 12.03.07 at 1:31 pm

note the comparison of monozygote (MZ—‘identical’) twins and dizygote (DZ-’frateral’) twins. That’s the control for in utero effects!

I take it that an MZ twin shares a uterus with an MZ twin, while a DZ twin shares a uterus with a DZ twin. It’s not at all clear to me how that facilitates controlling for in utero effects.

By the way, I do appreciate the links, but since you are providing them it isn’t necessary to paste chunks of text from them.

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goatchowder 12.03.07 at 4:52 pm

This whole nonsense reminds me of my youth, when my friends and I would sit around and argue forcefully and bitterly over which sub-sub-subgenre within the genres of rock/punk/hip-hop/prog music was better than the other, when they all used the same three fscking chords and 4/4 beat.

Out of all of our DNA, what percentage of it on average varies between “races”? There has to be a factual answer to this question out there somewhere. Less than 1% perhaps, just to take a wild guess?

Why the hell is anyone arguing over this crap?

123

BigDon 12.03.07 at 4:58 pm

Lynn, “Race Differences in Intelligence”
Hart, “Understanding Human History”

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Brett Bellmore 12.03.07 at 5:01 pm

“You are Brett or David and I claim my prize.”

Nope, I always post under my own name, except in neighborhoods a heck of a lot rougher than this one. For all that I think Henry’s decision to limit me to one comment a day in response to other commentors swearing at me is a crock, it’s not my forum, and I’m a libertarian enough to respect it. Well, not respect as such, but comply. Sock puppetry is not my style.

I could make an evolutionary argument for a correlation between brain size at birth, and intelligence, based on the fact that conflict between head size at birth and the size of the birth canal, (Limited due to our bipedal habits.)is putting both mother and child at not insignificant risk of death; Gotta be SOME evolutionary benefit to being born with large heads, or else they’d be small enough to easily deliver, and intelligence is the obvious candidate. But the chief driver for adult brain size is body size.

Oh, and Sg, phrenology? You really think I’m stupid enough to think that a lump of stuff that makes jello look rigid is dictating the shape of a person’s skull? There’s pretty much got to be some mechanism driving the skull to accomidate the brain’s volume, but the brain clearly adopts whatever shape the skull ‘choses’ to impose.

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Walt 12.03.07 at 5:18 pm

It’s either this or which rock/punk/hip-hop/prog music is better than the other.

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Mitchell Young 12.03.07 at 6:21 pm

No, think is my real name. There are tons of Mitchell Young’s out there, so its kinda anonymous. I think people should, when discussing sensative topics, use real, or at least semi-real, names (i.e. just a first name). Makes for politeness.

As for why we discuss this? Well, whether thrash core is better than death metal is not going to affect, say, affirmative action (or what is called positive discrimination in Britain) which limits my potential children in their life chances. If we recognize that different talents are distributed across groups, then much of the rational for such programs goes away. Indeed, maybe universities will do away with shams such as “critical whiteness studies” if it gradually dawns on people that differing levels of educational achievement are not the result of some phantom institutional racism, but due to nature and/or nuture questions that we cannot solve. I don’t think so — the ‘diversity industry’ (www.diversity.com , see also Tim Wise, who makes money with very public self-flagelation) is too entrenched. But we can hope.

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Mitchell Young 12.03.07 at 7:41 pm

I take it that an MZ twin shares a uterus with an MZ twin, while a DZ twin shares a uterus with a DZ twin. It’s not at all clear to me how that facilitates controlling for in utero effects.

Because, each half of the twin pair — in say an adoption study — will have shared the same gestation environment, using enough MZ and DZ twins effectively controls for pre-natal environment. Using a proper number of these pairs — via matched pairs “of pairs” or simply randomization, if the groups (that is, the mz pairs vs. dz pairs)display differences it is completely genetic. Actually I believe that dz twins do show higher IQ correlation than siblings in most studies, but that mz twins show higher correlation yet.

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Seth Finkelstein 12.03.07 at 8:31 pm

Here you have the political agenda of Scientific Racism stated about as explicitly as you’ll ever see it in polite company: “If we recognize that different talents are distributed across groups, then much of the rational for such programs goes away.”

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LizardBreath 12.03.07 at 8:32 pm

if the groups (that is, the mz pairs vs. dz pairs)display differences it is completely genetic.

Or, you know, due to the increased similarity of environment due to other people being unable to distinguish identical twins.

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Walt 12.03.07 at 9:02 pm

Well, Mitchell, I have to give you credit for being up front about your racial agenda.

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Mitchell Young 12.03.07 at 9:20 pm

I would consider it a non-racial agenda.

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Mitchell Young 12.03.07 at 9:26 pm

Or, you know, due to the increased similarity of environment due to other people being unable to distinguish identical twins.

lb, most twin studies are twins raised apart. Being confused for an identical sibling doesn’t play into it.

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LizardBreath 12.03.07 at 10:59 pm

lb, most twin studies are twins raised apart.

Most? I don’t think so. There’s the Minnesota study, but isn’t it generally quite difficult to assemble enough separated twins to do a study on them?

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Kevin Donoghue 12.03.07 at 11:06 pm

Mitchell Young: Actually I believe that dz twins do show higher IQ correlation than siblings in most studies, but that mz twins show higher correlation yet.

The fact that MZ twins are invariably of the same sex, while DZ twins need not be, could have something to do with that. (The study you linked to above was all-female, but that’s not typical.) And for twins of either kind, raised in the same home, it is worth noting that such variables as family income will be the same for them at all stages of their development, which is not the case for non-twin siblings. These are just two of the points which Cosma Shalizi mentioned in a long post which took most of the shine off twin studies as far as I’m concerned.

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SG 12.03.07 at 11:42 pm

I’m interested mitchell, exactly what social programs are wasted on these poor stupid black people? Please enumerate, so I can see how the tiny IQ gap matters?

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Mitchell Young 12.04.07 at 1:13 am

sg, look to the post, I give an example: affirmative action, and imply another, the vogue for ‘critical whiteness studies’ . And please don’t put words in my mouth — a cheap debaters trick. I have never once written or said ‘stupid black people’ .

lb, I fair point, I have no idea how many twin studies involve ‘separated at birth’ and likely the majority involve twins raised together. But in that case, if 100% environmentarianism was true, one would expect the same mean difference in IQ among dz twins and mz twins raised by birth parents — given a large enoigh sample. I don’t know if that is the case, I doubt it. Be worth looking into.

KD, the studies I have read all have more than one mz and dz pair, they involve both sexes. It is true we have no mz pairs of different sexes, but I can’t see what difference that would make — we do have dz pairs of the same sex for comparison.

I’m out of here– work to do.

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SG 12.04.07 at 8:31 am

mitchell, it was just a turn of phrase – there is no difference between “people with a lower IQ than white people” and “people stupider than white people”. It’s quicker to say “stupid black people” than “black people who are potentially not as intelligent as white people”.

Now it seems you are backing away from any kind of claim except that “affirmative action” (your example being college placement) is affected by this putative stupidity. But surely we can assess the effectiveness of blacks at college by, say, their college marks rather than their IQ? seems more direct to me… And in any case affirmative action is not about promoting stupid people – it is about overcoming racist barriers.

i.e. until we can guarantee that nowhere in the system is a black person being held back because they are black, all this discussion of IQ is irrelevant. Unless of course we could claim that black people just don’t manage at university – which can be assessed using their university grades, don’t you think?

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dsquared 12.04.07 at 9:06 am

most twin studies are twins raised apart

note that even in the context of the best twin studies “raised apart” can mean “raised in the same town and going to the same class of the same school”.

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Mitchell Young 12.04.07 at 11:34 am

sg
First, you are wrong on your rephrase. Its not the same , either in tone or content, to say group X is stupider than to say that group X has a lower mean IQ. Now substance

The logic of affirmative action is this: there are disproportionately fewer X at institution Y, or group X performs at a lower level than group Y. This must be because of ‘institutional racism’ or the racism of members of Y. But if Murray, Rushton, Jensen, Gottfriedson and others are right, the reason lies at least in part in differential distribution of abilities among population groups.

This first attitude results in collosal wastes of time and resources such as the Achievement Gap Summit , not to mention the insult that such programs are to Californias teachers, esp. white teachers. It results in discrimination against white kids and Asian kids trying to get into college — which is we can’t leave it for assessment by university grades. But no doubt you are familiar with Richard Sander’s work on law school affirmative action, law school grades and bar examination failure.

Okay, that’s really my final word… this has been entertaining but too time wasting.

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SG 12.04.07 at 12:01 pm

Yes mitchell, but don’t you think that in a society recovering from slavery of blacks by whites, ruling out institutional racism before ruling in IQ would be sensible? For all we know they may, for example, have gone to poorer schools… and even if they do worse at university, how do you know that’s not because of institutional racism? Even if they are dumber as a race, unless you want to conclude that they are so stupid they can’t go to uni, surely institutional racism could be an issue…?

And if having a lower IQ doesn’t make you stupider, how does it affect college achievement? And wouldn’t it be more sensible to use college grades to judge that?

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Mitchell Young 12.04.07 at 1:43 pm

I have this little game I like to play…the internet makes it easy. When someone makes claims about racism/xenophobia etc I go to the institution’s webpage and check out the demographics.

Well, just did the same thing with the Crooked Timber contributors list. How to put this — it is extremely caucasian. Chris Bertram looks like he might be, I don’t know the PC term, but ‘mixed’ let’s say. Everyone else that have an image, or have put up a sort of avatar (Waring and Holbo, ‘Montagu Norman’), seem to be pretty darn white. Or ‘white’ as some say.

Now, is Crooked Timber institutionally racist?

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Kevin Donoghue 12.04.07 at 1:50 pm

Mitchell Young: …we do have dz pairs of the same sex for comparison.

Merely having the data is not enough – unless the actual number-crunching is done we can’t derive results. Was it done? I don’t know and, judging by the fact that you have no idea how many twin studies involve twins separated at birth, my guess is that you don’t know either.

All in all, you seem to have more interest in collecting ammunition to use against affirmative action than in evaluating this research on its merits. It’s not for me to advise you on how to wage that struggle, but FWIW your approach doesn’t make any sense to me. Even if it is ever established that low IQ is related to a genetic defect, that won’t affect the case for remedial action. Whether a disadvantaged group should be helped or not doesn’t depend on whether their handicap is traceable to their genes. Many people are crippled by diseases which have a genetic component, but I’ve never heard anyone using that as an argument against providing wheelchair ramps in public spaces.

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Kevin Donoghue 12.04.07 at 1:54 pm

Mitchell Young, reappearing after yet another exit: Now, is Crooked Timber institutionally racist?

Maybe it depends on whether you count the Irish as white? Most racist league tables put us a long way down the rankings.

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SG 12.04.07 at 2:18 pm

well Mitchell, it’s a blog… maybe they’re just a bunch of mates? It’s certainly an amusing way of avoiding answering my question. Why do you recommend IQ as a measure of the potential benefits of college affirmative action programs when college grades would suffice? And how does it even affect affirmative action programs, given the possibility that its influence on college outcomes is confounded by institutional racism?

(Now is your chance to follow up the previous comment and admit you don’t believe institutional racism exists…)

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Ray 12.04.07 at 2:41 pm

Have the Crooked Timber members ever claimed, explicitly or implicitly, that they are the smartest possible set of blog posters?

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Mitchell Young 12.04.07 at 5:28 pm

Really gonna have to leave now. Maybe someother time.

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David Kane 12.04.07 at 7:58 pm

Apologies for the delay (especially to baa). I had meant to put a meaningful comment together but I am still afraid that Henry means it when he says that I am now banned from his threads. So, I’ll save that essay for another venue rather than post it here with the risk that it might be deleted.

In closing, let me point out something that James Flynn wrote about Arthur Jensen.

I never suspected Arthur Jensen of racial bias. Over the years, I have found him scrupulous in terms of professional ethics. He has never denied me access to his unpublished data. His work stands as an example of what John Stuart Mill meant when he said that being challenged in a way that is “upsetting” is to be welcomed not discouraged. Before Jensen, the notion that all races were genetically equal for cognitive ability had become a dead “Sunday truth” for which we could give no good reasons. Today we are infinitely more informed about group differences. Equally important, the debates Jensen began are revolutionizing the theory of intelligence and our understanding of how genes and environment interact.

Why does that matter?

1) In puts into context Cosma’s insistence that most/all of those on the other side are “blithering idiots.” It was one thing to dismiss Rushton and Lynn as “charlatans.” It is another to attack someone like Jensen in the same way. (Cosma does not do this directly but everything he writes is consistent with my belief that he would put Jensen in the same category.) But, Cosma, on the one hand, clearly wants to believe that someone like Flynn does valuable/important/useful work, but Flynn has great things to say about Jensen (and also, I think, Rushton and Flynn). He doesn’t agree with all their views, but he relies on their data and considers them welcome members of the scholarly community. But how can he include Flynn within the tent while kicking out Jensen/Lynn/Rushton when Flynn would tell him that those three deserve admittance also?

2) And this all connects to Lancet. Really! My professional interests have little to do with race or IQ or g or Iraqi mortality. But I am a stickler for process, for scientists behaving the way that they ought to behave. Hate him or love him, but Jensen does so. (I understand that the same is true for Rushton and Lynn.) Contrast that with the behavior of Les Roberts who, to this day, refuses to share the household level data from L1 with anyone or that same data with some of his critics on L2.

Jensen shares his data with his fiercest and most intelligent critics. Roberts doesn’t. Only one of them is a real scholar. Can Henry or Daniel or Kieran tell the difference?

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Walt 12.04.07 at 8:31 pm

That may all be true, David, _you_ do not behave like a real scholar. A real scholar is humble in the face of their own ignorance. You didn’t understand the Lancet paper, you do not understand the basics of frequentist inference, and based on your non-understanding, you accused Roberts of fraud. You then tried to use Tim Lambert and Daniel and a bunch of other people as part of your crusade against Roberts. to Maybe Roberts should release his data. But maybe you should learn how to do the statistics before you accuse someone else of making up the answers.

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baa 12.04.07 at 8:41 pm

David,

Thanks for your contribution here. And I’ll look forward to your future post on the topic with interest.

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Walt 12.04.07 at 9:04 pm

Oh my God.

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Walt 12.04.07 at 9:15 pm

According to this article in Slate here, Jensen has been trying to prove that the black-white IQ gap is hereditary since the 60s. From the 60s until today, we have performed a large scale experiment of reduced racism. The result of that experiment? The gap in black-white IQs has shrunk. Since racism has not vanished entirely (something that I believe is slowly happening), why is it so hard to believe that the gap won’t vanish entirely as well?

The Slate article also points out a recurring theme in these IQ stories, one that explains Cosma’s frustrations: I have heard hereditarians bring up the Minnesota twin study. It turns out that the study has serious design flaws that make the results hard to interpret. Hereditarians will never, ever state these flaws when they when they bring up the study. Here’s Slate:

Here is what you would never know about the Minnesota study from reading Jensen and Rushton, or, for that matter, Saletan. It held neither race nor expected IQ constant; the black children were adopted at a later age than the other children, which the study’s own authors note is associated with depressed IQ; the black children’s mothers had lower educational levels than those of the white children; the “quality of placement” for the white children was higher than for the other children; and as the study’s own authors have noted, the black and mixed-race children experienced severe adjustment problems as they grew up.

This is the behavior of a true scholar?

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Kevin Donoghue 12.04.07 at 10:17 pm

Walt,

Readers will soon find it hard to make sense of your comments since Henry will surely delete David Kane’s comment as soon as he sees it. More’s the pity because the soon-to-vanish comment is priceless. I hope Henry won’t object if I post a summary, although I recognise that doing so undermines the purpose of banning a troll.

David argues that since Cosma Shalizi respects James Flynn, and James Flynn respects Arthur Jensen, really it is (somehow) wrong that Cosma does not respect Arthur. Apparently there is a transitivity axiom at work here; I can’t quite make sense of it, since by induction it implies that Cosma should also respect known frauds like the late Sir Cyril Burt – which looks very like a reductio to me.

A further complaint is that Les Roberts, an epidemiologist who has devoted years of his life to studying mortality in hellholes like DR Congo and Iraq, in the hope of getting Western governments to do something about the dreadful conditions he has witnessed, wasn’t as helpful to his critic David Kane as David thinks he should be. Contrast that ungracious conduct with the exemplary behaviour of Arthur Jensen, who has devoted much of his life to demonstrating that African-Americans are an inferior breed on whose education public funds should not be wasted; Jensen was very helpful to Flynn, his critic. So clearly Jensen is a scholar and a gentleman and Roberts is neither.

I kid you not, folks. That’s what David Kane has to say. For those not in the know, David Kane has (without a scrap of evidence) accused Les Roberts and his colleagues of publishing a fraudulent study. I rather suspect Jensen’s attitude to Flynn would have been a bit less helpful if Flynn had behaved as Kane did. Another point of difference is that while Jensen can hardly dispute Flynn’s knowledge of psychology, Kane has shown himself unable to compute a crude mortality rate, even when the figures are supplied to him in a spreadsheet with the formula already entered. I wish I was joking but I’m not.

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Barry 12.04.07 at 10:21 pm

Posted by dsquared: “note that even in the context of the best twin studies “raised apart” can mean “raised in the same town and going to the same class of the same school”.”

I’d hazard a guess that twins in the studies tended to have far more similar social circumstances than a near-random ‘assignment’ to society would have.

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Kevin Donoghue 12.04.07 at 11:10 pm

Henry,

On reflection, if (and only if) you are deleting David Kane’s comment (7:58 pm), please delete my response (10:17 pm) as well. Not that his tripe deserves better, but I wouldn’t ask readers to take my word for that. Thanks.

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SG 12.04.07 at 11:48 pm

David Kane, perhaps Jensen could share his data because the subjects weren’t about to be murdered for co-operating with him? Perhaps also because back in the 60s, when black people were still being experimented on as syphilis carriers, research ethics aren’t what they are today?

I’m impressed that you managed to get your sly accusations of fraud in again there though. Keep at it!

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Kevin Donoghue 12.05.07 at 5:26 pm

Some o’ them super-smart asians designed a new test for cognitive functioning. Guess who won.

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