So now we are back to my original question – what evidence do you have that parents do tend to transmit their advantage to their children by the mechanisms you list? Judith Harris presents evidence that “parenting styles” and “values transmission/ambition formation” has very little impact once genetics is controlled for, I am curious as to what your evidence is that they are indeed mechanisms.

As for your main argument, I do not have a copy of The Nuture Assumption at the moment, that book shares with Gun Germs and Steel the feature of compulsive lending, so I cannot check your claim that Judith Harris does not use direct information about parenting styles. However Judith Harris has published some articles online. In http://home.att.net/~xchar/tna/devpsyjh.htm, she looks at studies on intervention effects.
From that study:
“A study that meets all the criteria for an experimental test of my prediction was carried out recently by Forgatch and DeGarmo (1999). There was a control group, the intervention occurred only at home, and the children’s behavior was assessed both at home and at school. Ratings at school were made by teachers who were blind to the children’s experimental group assignment. But, “contrary to expectations” (p. 718), the researchers found no differences between the teachers’ postintervention ratings of children in the intervention and control groups. ”

So in this case there was a purposeful change in parenting behaviour, which had an impact at home, but not at school.
And in a summary of more general research:
” Similar conclusions have been reached in regard to programs designed to improve the school adjustment and academic performance of children living in poverty: “There is little evidence that parenting programs produce the hoped-for linkage between changed parent behaviors and improved child outcomes” (St.Pierre & Layzer, 1998, p. 7; see also White, Taylor, & Moss, 1992; Zaslow, Tout, Smith, & Moore, 1998).”

If parenting styles affected children’s success in life, then changing parenting styles should show some impact in terms of behaviour at school.

And she cites another study on parent behaviour and child (well teenage) behaviour:
” Reiss and his colleagues studied 720 pairs of same-sex adolescent siblings (identical and fraternal twins and full, half and stepsiblings) over a 3-year period, from early to mid-adolescence. The adolescents’ behavior and adjustment, and the behavior of their parents, were judged by observers, the parents, and the adolescents themselves; these multiple sources of information were combined to produce measures of unusual reliability.
Reiss has confessed that he was “shocked” by the results of his study (Paul, 1998, p. 46). The results are indeed shocking to believers in the nurture assumption (and Reiss, in spite of everything, remains a believer). Virtually all correlations between parental behaviors and child outcomes were accounted for by genetic factors. The parents did indeed treat their children differently but they were reacting to genetic differences among the children, rather than causing the differences.”

So Judith Harris does have at her fingertips studies of parental behaviour, not just parental personality. From my vague memory, she included these or similar studies in The Nurture Assumption as well, but my memory is of course unreliable. And I can hardly expect you to prove a negative. But if Judith Harris did include these studies that would explain why she didn’t make the assumption you mentioned explicit – she didn’t need to make your assumption at all.

So you are saying that, say, in a hypothetical world where lazy, relaxed parents unintentionally produced over-anxious, anal-retentive children, (maybe because the children overcompensated for their parents’ laidback attitudes, and carried this attitude on into adult life), this would not show up in correlation studies, as the parents did not mean to pass on their personality traits?

While my interest in the topic immediately under discussion is only personal, I do deal with correlations a lot in my professional life, and this idea is sending chills down my spine that I have been doing it all wrong for years and years. I need to know when and where I have to make assumptions about the motivations of people in order to be able to draw the conclusion that no correlation implies no causation. And also I need to know what sort of assumptions need to be made. I am really really surprised and distressed that none of my statistics teachers or lecturers bothered to mention such a fundamental problem with correlation studies. Can you please provide the name of a handbook about how to do this? Or a teacher in this subject?

I am also extremely curious about the mathematics behind this result. We of course studied the correlation formulae, and least-squares regression models, and etc, in class, and I don’t recall anything in that that was at all dependent on the motivation of whatever correlation you were studying. I do love counter-intuitive mathematical proofs for their own sake – can you please provide a link or a reference to the proof that such motivations must be taken into account when doing correlations?

Tracy W—yes, a good deal of that literature does, in different ways. Some doesn’t. All of it, by the way, is sceptical that bequest plays much role. As to Harris—well she doesn’t actually have any data about parenting styles (that’s not what her studies are about). She looks for correlation between personality traits of parents and those of children. If you assume that no correlation after controlling for genetic effects allows you to say that parenting styles have no effects, then you do, indeed, have to make an assumption about the aims of parents. Its a long time since I read Harris, and maybe she doesn’t claim that parenting styles have no effects, in which case there is no need to make the assumption, but what she says has no bearing on the effects of parenting styles.

As for The Nuture Assumption, I don’t know why you think the assumption you describe is relevant to the results Judith Harris describes. Correlation studies are independent of theories about motivation – the high rate of haemophilia amongst Queen Victoria’s descendents is not evidence that Queen Victoria tried to create haemophilic descendents. If parenting styles had a consistent effect on children’s personality traits that should show up in correlation studies regardless of the parents’ motivations.
I suspect the reason Judith Harris never made such an assumption as you describe explicit is that she never made such an assumption at all.

Which leads me to your question on why yours is Western, modern, Eurocentric, and Christian (or for that matter even Northern Euro-centric, 17th century, and Lutheran). It is because family being defined with “man and woman” as the centerpiece, is all that. Elsewhere in the world, family is a genetic identification with a plurality of individuals (patriarchal or matriarchal or both) and joint prima facie claim on all available resources enjoyed by them. Uncles and cousins taking full charge and bequething the whole lot to children without parents is not only not rare, it is extremely common.

Also, no biological/genetic imperatives to ensure immortality (and hence, the overly loving importance of grand-parents/children)?