Food neophobia can be observed in most animals and may play a key role in diet selection, especially for generalist species. This project contains five experiments aimed at elucidating the role of food neophobia in the feeding behavior of rhesus macaques (Macaca mulatta). Of primary interest was whether the macaques' behavior matched predictions derived from the hypothesis that food neophobia develops after repeated experiences of conditioned taste aversion (CTA) with novel foods. In a variety of experimental conditions, the observer recorded how long subjects manipulated novel and familiar foods, the frequency of sniffs, and whether food was eaten or dropped at the end of a trial. Food neophobia increased predictably in semi-free ranging macaques with increasing food novelty. As expected, this pattern did not hold in corral-housed animals. The source of food was important, as subjects were more likely to drop novel foods they discovered in their environment compared to those hand-tossed to them by a human observer. Macaques, as young as 1-year old, exhibited food neophobia. This result does not support the CTA hypothesis, but studies with younger infants are warranted. Pilotdata on 6-month old macaques indicate that social cues from group members may influence infants' behavior toward novel food.