Learning about Other Persons’ Character Traits Relies on Combining Reinforcement Learning with Representations of Trait Similarities

Abstract

Humans often describe other persons (and themselves) in terms of abstract character traits. When getting to know a new person, they need to update their estimates of the other person across many different character traits. It is unclear how this learning process unfolds and how the relationship between diverse character traits are represented in brain activity. Here, we first showed in three behavioral studies that humans combine reinforcement learning with their knowledge about the correlations between traits when learning about other persons’ character. Second, in two functional imaging studies the fine-grained similarities between character traits were represented in medial prefrontal cortex, in a region that has consistently been linked to thinking about other persons. Our findings thus suggest a possible learning mechanism for rather complex generalization across character traits according to their similarities, which seem to be related to the medial prefrontal cortex.