Belief–desire reasoning in the explanation of behavior: Do actions speak louder than words?

The mechanisms underwriting our commonsense psychology, or ‘theory of mind’, have been extensively investigated via reasoning tasks that require participants to predict the action of agents based on information about beliefs and desires. However, relatively few studies have investigated the processes contributing to a central component of ‘theory of mind’ – our ability to explain the action of agents in terms of underlying beliefs and desires. In two studies, we demonstrate a novel phenomenon in adult belief–desire reasoning, capturing the folk notion that ‘actions speak louder than words’. When story characters were described as searching in the wrong place for a target object, adult subjects often endorsed mental state explanations referencing a distracter object, but only when that object was approached. We discuss how this phenomenon, alongside other reasoning “errors” (e.g., hindsight bias; the curse of knowledge) can be used to illuminate the architecture of domain specific belief–desire reasoning processes.