Belief Neglect: A Heuristic in Social Reasoning

Humans are capable of sophisticated social reasoning. This capability is often attributed to a folk theory of mind, which rationally links inferences about the beliefs and desires of another person to their observed behavior through a form of inverse planning. Evidence suggests, however, that people do not consistently exercise this capability. One reason may be that theory of mind is computationally costly. Heuristic methods can circumvent some of these computations, particularly when reasoning about routine behavior. We explored the conditions under which people engage in full inference versus heuristic approximations. We found that participants selectively neglected the beliefs of other agents when inferences about these beliefs were not necessary for predicting behavior. This “belief neglect” appeared to be the default behavior; participants exhibited belief sensitivity only with training on a task where belief inference was necessary. These findings suggest that people are capable of adaptive cognitive resource allocation in social reasoning.