Citation

Young L, Camprodon JA, Hauser M, Pascual-Leone A, Saxe R. Proc. Natl. Acad. Sci. U. S. A. 2010; 107(15): 6753-6758.

Affiliation

Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139; Berenson–Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215; and Departments of Psychology and Human Evolutionary Biology, Harvard University, Cambridge, MA 02138. (lyoung@mit.edu)

Copyright

(Copyright © 2010, National Academy of Sciences)

DOI

10.1073/pnas.0914826107

PMID

unavailable

Abstract

According to a basic tenet of criminal law, "the act does not make the person guilty unless the mind is also guilty." Like legal doctrine, mature moral judgment depends on the ability to reason about mental states. By contrast, young children's failure to reason fully and flexibly about mental states and, in particular, to integrate mental state information for moral judgment leads them to focus instead on the action's consequences.

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.

This article contains supporting information online at:
www.pnas.org/cgi/content/full/0914826107/DCSupplemental.