Samantha Monier, masters thesis, Columbia University, winter 2016
Abstract:
Theory of mind, or the ability to see others in terms of mental states, allows us to predict and interpret one another’s behavior. Though controversial, there is some evidence non-human primates may understand what others see, know, hear, infer, and intend, yet there is little evidence that they can reason about another’s beliefs. Belief representation means being aware that others can be governed by information that is inaccurate or incompatible with one’s own.
To better understand which factors affect a monkey’s performance on a looking time test of false belief representation, this study reanalyzes data collected on free-ranging rhesus macaques. I created linear models using the subject’s belief, age and sex, the agent’s belief, and the field season in which data were collected, as predictors of the subject’s looking time. The models show an interaction between sex and agent belief such that male macaques look longer after witnessing a human agent exposed to false, rather than true, belief conditions. This analysis provides some of the first evidence that animals may be able to represent another’s beliefs, suggesting the need for more testing of this kind.