Edited by Nancy G. Kanwisher, Massachusetts Institute of Technology, Cambridge, MA, and approved January 10, 2011 (received for review August 9, 2010)
↵1J.M.M. and L.L.Y. contributed equally to this work.
High-functioning autism (ASD) is characterized by real-life difficulties in social interaction; however, these individuals often succeed on laboratory tests that require an understanding of another person's beliefs and intentions. This paradox suggests a theory of mind (ToM) deficit in adults with ASD that has yet to be demonstrated in an experimental task eliciting ToM judgments. We tested whether ASD adults would show atypical moral judgments when they need to consider both the intentions (based on ToM) and outcomes of a person's actions. In experiment 1, ASD and neurotypical (NT) participants performed a ToM task designed to test false belief understanding. In experiment 2, the same ASD participants and a new group of NT participants judged the moral permissibility of actions, in a 2 (intention: neutral/negative) × 2 (outcome: neutral/negative) design. Though there was no difference between groups on the false belief task, there was a selective difference in the moral judgment task for judgments of accidental harms, but not neutral acts, attempted harms, or intentional harms. Unlike the NT group, which judged accidental harms less morally wrong than attempted harms, the ASD group did not reliably judge accidental and attempted harms as morally different. In judging accidental harms, ASD participants appeared to show an underreliance on information about a person's innocent intention and, as a direct result, an overreliance on the action's negative outcome. These findings reveal impairments in integrating mental state information (e.g., beliefs, intentions) for moral judgment.
Author contributions: J.M.M., L.L.Y., R.S., and J.D.G. designed research; J.M.M., S.M.L., D.O., and P.L.M. performed research; J.M.M., S.M.L., and D.O. analyzed data; and J.M.M., L.L.Y., R.S., and J.D.G. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1011734108/-/DCSupplemental.
*Belief refers to the understanding that another person holds a particular premise to be true (e.g., the belief that it will rain tomorrow), whereas intention refers to another person's determination to act in a certain way (e.g., the intention to bring an umbrella), based on one or more beliefs.
