Food-washing behaviour in tufted capuchin monkeys, Cebus apella, and crabeating macaques, Macaca fascicularis

Abstract

Behaviour patterns of non-human primates that are labelled ‘cultural’ may arise and diffuse through several processes. Assessing the contribution of various processes requires full knowledge of the history of the phenomenon. In the present study, food washing, the most quoted example of protocultural behaviour in monkeys, was investigated. All individuals in small groups of capuchins and crabeating macques treated sandy food and water as they had previously treated toys and water. The majority of individuals consistently washed sandy food. In two large groups of capuchins, however, only a few individuals did so. There was no evidence of imitation, in either the large or the small groups. Individual discovery within a supportive social context can account for the appearance of food washing among several members of a group.