Intragroup behavioral variation in white-fronted capuchin monkeys (Cebus albifrons): mixed evidence for social learning inferred from new and established analytical methods

The study of socially learned traditions in field settings has been complicated by the need to rule out alternative hypothesized causes of behavioral variation, including underlying genetic variation, and asocial reinforcement learning that shapes behavior in response to microecological variations. Intragroup associations of spatial proximity and behavioral similarity support the tradition hypothesis when the associations are predicted specifically by social learning and not by alternative hypotheses. This paper attempts to test for socially learned traditions by combining variations in multiple foraging techniques into pairwise behavioral similarity matrices. This method thereby avoids loss of power from conducting multiple statistical tests. These matrices are then compared through correlation and cluster analysis to a proximity association matrix. Cluster analysis enables very specific predictions to be made from the social learning hypothesis, predictions that are not particularly likely under alternative hypotheses that do not invoke social learning or traditions. The results are mixed, with binary behavioral variations being consistent with a traditional influence of social learning, and with variations in the frequency of technique use being inconsistent with traditions.