Abstract # 13100 Poster # 93:

Scheduled for Thursday, August 9, 2018 06:00 PM-08:00 PM: (Chula Vista ) Poster Presentation


DO YOUNG RHESUS MONKEYS (MACACA MULATTA) KNOW WHAT OTHERS SEE?: A COMPARATIVE DEVELOPMENTAL PERSPECTIVE

A. M. Arre and L. R. Santos
Yale University, Department of Psychology, 2 Hillhouse Avenue, New Haven, Connecticut 06511, USA
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     For decades, primatologists have tested to what extent non-human primates share a human-like ability to think about the perceptions and beliefs of other individuals – what researchers have referred to as having a “theory of mind” (ToM). While we know that adult primates possess some aspects of human ToM abilities, little work has examined whether the developmental shifts present in human ontogeny are shared with other primates. To address this, we tested ToM abilities in a population of young rhesus macaques (n=240) at the Cayo Santiago Biological Field Station. We used the looking-time paradigm, allowing us to infer subjects’ expectations by measuring the duration of time they spend attending to different stimuli. To explore what developing monkeys know about others’ visual perspective, we compared their looking time to two events: one in which an experimenter acted consistently with her visual perspective, and one in which she acted inconsistently. Adult monkeys show a ‘violation-of-expectancy’ effect on this task: they look longer when the experimenter acts inconsistently with her visual perspective. Our results indicate that infant rhesus monkeys (< 1 year-old) do not share this expectation: they look longer in the expected than the unexpected condition (p=0.06). In contrast, juveniles (2 to 5 years) show an adult-like pattern of looking (p=0.09). Despite divergent socioecology, rhesus macaques show delayed, yet human-like, development in their understanding of others’ perceptions.