Abstract
Many new behaviors have been reported to appear in primate troops, but were either idiosyncratic, or independently adopted by very few individuals, or their performance was restricted to a small class of the population, and for some reason, they never widely spread within the group by social means to become traditions. Among the various behavioral innovations reported in Japanese macaques (Macaca fuscata), we focused on three behaviors: fish-eating on Koshima Island, dental flossing at Arashiyama, and stone handling in four captive and six free-ranging troops across Japan. We used longitudinal and cross-sectional data to explore the history and assess the current prevalence of these behaviors at the group-level. We examined the factors that may have favored these innovations, including the environmental context, the individual characteristics of the innovator, and the structural and functional aspects of the behavior. Group size, kinship, and dominance are socio-demographic factors that are likely to limit the opportunities for any group member to observe the innovator, and thus constrain the diffusion or maintenance of these potential candidates for behavioral traditions. Identifying the determinants of innovations and the constraints on their diffusion within social groups of non-human primates is of special interest to understanding cultural evolution in hominids.
Sponsors: Lavoisier Grant (Ministère des Affaires Etrangères, France); JSPS postdoctoral fellowship (No. 07421); Grant-In-Aid for scientific research (No. 1907421, Ministry of Education, Science, Sports and Culture, Japan)
Keywords: social learning, innovation, tradition, behavioral variants, tool-use, Macaca fuscata
