Pointing fingers at others: The neural correlates of actor-observer asymmetry in blame attribution

People tend to describe others' immoral behaviors as intentional and dispositional, and their own as unintentional events. The actor-observer asymmetry might reflect at least true attitudes potentially free from intentional faking. Implicit attitudes — i.e., automatic evaluation of the rightness or wrongness of actions — play a central role in guiding moral decision-making. Yet, little research has investigated how value computations are associated with actor-observer asymmetry of moral decision-making. In this fMRI study, we developed the morally-laden implicit association test (mIAT) to examine the extent to which implicit attitudes are predictive of online neural response when participants mentally simulate or passively observe morally-laden behaviors such as helping or harming others. Results showed that the scores on the mIAT were predictive of actor-observer asymmetry when attributing blame for immoral behavior, associated with neural responses in the orbitofrontal cortex and temporal pole. The asymmetry between first-hand experiencing and passive viewing moral behavior recruited the activity in the dorsolateral prefrontal cortex and right temporoparietal junction. These findings indicate that implicit moral attitudes can predict moral evaluation and neural responses to asymmetry between experiencing and observing injustice. They provide important knowledge regarding the individual differences involved in the computational mechanisms underlying how implicit attitudes guide moral decision-making.