Grant: Discovery Grants Program - Individual

This project is a crucial piece of a larger research program spanning several disciplines that has been underway for over four decades: to piece together the origins of human theory of mind. Theory of mind is the ability to attribute internal, mental states to others and to predict their behavior on that basis. Humans become adept at making judgments about what others perceive, feel, want, know, and intend from an early age. However, despite decades of research, whether our closest primate relatives, chimpanzees, share this ability is still a hotly debated issue. Some researchers claim there is enough evidence to conclude that chimpanzees can attribute perceptions, desires, intentions, and knowledge to others, but they are not able to infer mental states that are at odds with reality (e.g., false beliefs). Others argue that this conclusion is highly premature for two reasons: (1) the apes' ability to infer other types of false mental states (e.g., false perceptions) have not yet been tested; and (2) the positive results from some tests can be given simpler explanations: apes could have passed by using behavioral or environmental cues, without ever considering the mental state of the other individual. This is due to a pervasive methodological problem that cuts across all research carried out to date in this area, called Povinelli's Problem. My research aims to address the two issues listed above by testing false perception attribution in apes using a novel method that overcomes Povinelli's Problem. Chimpanzees will be given tasks in which they must predict another individual's behavior by making inferences about their mental state, in a situation that makes it impossible for them to use behavioral or environmental cues. The results will be of interest to anyone who strives to understand the evolutionary roots of our own social cognitive abilities. My research also has the potential to solve a longstanding methodological problem in the field and thus lead to greater consensus on the subject of ape theory of mind.