MIT researchers have shown that people’s moral judgments change when the functioning of a certain part of the brain is suppressed using magnetic stimulation. Here’s the abstract:
When we judge an action as morally right or wrong, we rely on our capacity to infer the actor’s mental states (e.g., beliefs, intentions). Here, we test the hypothesis that the right temporoparietal junction (RTPJ), an area involved in mental state reasoning, is necessary for making moral judgments. In two experiments, we used transcranial magnetic stimulation (TMS) to disrupt neural activity in the RTPJ transiently before moral judgment (experiment 1, offline stimulation) and during moral judgment (experiment 2, online stimulation). In both experiments, TMS to the RTPJ led participants to rely less on the actor’s mental states. A particularly striking effect occurred for attempted harms (e.g., actors who intended but failed to do harm): Relative to TMS to a control site, TMS to the RTPJ caused participants to judge attempted harms as less morally forbidden and more morally permissible. Thus, interfering with activity in the RTPJ disrupts the capacity to use mental states in moral judgment, especially in the case of attempted harms.
So basically, they have identified a part of the brain that is important in attributing mental states to others. And the moral judgments of normal adults depend on attributing mental states – intentions, specifically – to others. When they suppress the functioning of this part of the brain, moral judgments alter.
“We judge people not just for what they do, but what they’re thinking at the time of their action, what they’re intending,” [Liane] Young says. But, she says, a brief magnetic pulse was able to change that.
[The resulting judgments are] the sort of moral judgment you often see in kids who are 3 or 4 years old, Young says.
Interesting. The researchers themselves seem to be fairly careful in stating their results, but Joshua Greene – psychology professor at Harvard, Ph.D. in philosophy from Princeton – swings for the fences (although note that this is mostly a reporter’s paraphrase):
The fact that scientists can adjust morality with a magnet may be disconcerting to people who view morality as a lofty and immutable human trait, says Joshua Greene, psychologist at Harvard University. But that view isn’t accurate, he says.
[According to Greene,] The scientists are trying to take concepts such as morality, which philosophers once attributed to the human soul, and “break it down in mechanical terms.”
If something as complex as morality has a mechanical explanation, Green says, it will be hard to argue that people have, or need, a soul.
But of course the scientists are not adjusting morality with a magnet, they’re affecting people’s moral judgments. I don’t think anyone ever doubted that manipulating the brain in various ways can lead people to alter their judgments – moral and otherwise. This is obvious to anyone who has observed the results of alcohol, for example, or – much more indirectly – framing effects.
The experiment really doesn’t have much to say one way or the other about souls, meta-ethics, or the justification of any ground-level moral judgments. (Actually, it might suggest that you shouldn’t rely on your interpersonal judgments when the neural activity in your right temporoparietal junction is being disrupted by transcranial magnetic stimulation, or perhaps just when you’ve volunteered as a subject in an MIT lab.) Rather, it highlights the importance of attribution of intention in the moral judgment of normal adults, shows how localized in the brain this function is, and demonstrates how easily it can be suppressed in isolation from other functions. A plausible next step:
Sarah-Jayne Blakemore, a brain expert at University College London, said the findings were insightful.
“The study suggests that this region – the RTPJ - is necessary for moral reasoning.
“What is interesting is that this is a region that is very late developing – into adolescence and beyond right into the 20s.
“The next step would be to look at how or whether moral development changes through childhood into adulthood.”