Social Categorization
In-Group vs. Out-Group
Capuchin monkeys regularly encounter other social groups in the wild and respond in an agonistic manner not normally directed toward group members. This behavioral evidence suggests that capuchins have a concept of familiarity, or in-group vs. out-group, and know what category others belong to. Therefore, our first experiment investigating knowledge of social categories looked at capuchins’ ability to categorize individuals based on group membership. The capuchin colony at Yerkes houses two groups of capuchins, with approximately 15 individuals in each group. This allows us to ask questions about their social environment, as they are housed in groups much like what one would find in the wild. The task was presented to the subjects in an oddity task, much like the face recognition study. We found that subjects were able to categorize the images based on whether the individual depicted was from the in-group of the subject or the out-group (Pokorny, J. J. & de Waal, F. B. M., 2007).
