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Morality Magnets March 30, 2010

Posted by Dwight Furrow in Dwight Furrow's Posts, Ethics, Philosophy, Science.
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Research at MIT shows that moral judgments are affected by magnetic stimulation of the brain. 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.


Apparently, the part of the brain involved in understanding the intentions of others, when stimulated by magnetic fields, is suppressed, which understandably alters our moral judgments. The NPR report on this study points out that we judge intentions as well as actions. The magnetic pulse makes normal adults reason like 4 year olds.

Joshua Greene, the Harvard psychologist who has perhaps done the most important empirical work supporting the notion that morality is a function of the brain, thinks this kind of study has important metaphysical implications:

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. […]

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.

I’m not convinced that this study is all that important. It is not surprising that damage to the brain can affect our judgments. Furthermore, the fact that we can identify the part of the brain that accurately grasps the intentions of others tells us little about what we should do with that understanding. But I agree with Greene that the cumulative weight of the many studies showing various aspects of morality to be rooted in the brain suggests (without entailing) that notions such as the “soul” hypothesis do no explanatory work.

And as Jon Mandle at Crooked Timber points out:

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.

And Sarah-Jayne Blakemore, a brain expert and University College London, pointed out:

“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.”

Ah…I ‘m sure that it does—see Gilligan, Kohlberg et al.

H/t Crooked Timber

book-section-book-cover2 Dwight Furrow is author of

Reviving the Left: The Need to Restore Liberal Values in America

For political commentary by Dwight Furrow visit: www.revivingliberalism.com