Social Tolerance and Innovation in Capuchins: socially more tolerant brown capuchins are better problem-solvers than less tolerant white-faced capuchins

Innovativeness and social learning are the pillars of cultural evolution. While the role of social tolerance in social learning has long been acknowledged, its impact on innovativeness remains poorly understood. Here, we test six groups of captive white-faced capuchins (Cebus capucinus) and brown capuchins (Sapajus apella) to explore and compare the relationship between social tolerance and problem-solving propensities. White-faced capuchins are renowned for their rich repertoire of social behaviours, whereas brown capuchins are known for their diverse foraging repertoire, resulting in a broad range of culturally transmitted behaviours in both species. We performed a co-feeding experiment to assess species differences in social tolerance and a set of open diffusion novel food puzzles to test innovativeness. We measured associations for each possible dyad within each group during both experiments and compared the resulting social networks between conditions. We also measured neophobia in an independent experiment presenting groups with three novel objects. Overall, during both experiments, brown capuchins were more tolerant, and proportionally more individuals spent their time within the testing areas at any given moment. We also found that networks across experimental contexts were more similar in brown capuchins compared to white-faced capuchins. Moreover, although differences in approaching and exploring food puzzles were marginal, the success rate was higher in brown capuchins than in white-faced capuchins. Finally, neither eigenvector centrality within the networks nor neophobia could explain individual problem-solving success. Age was the strongest predictor for successfully extracting a food item. The results indicate that species-level differences in social tolerance may contribute to divergent innovation patterns, whereas individual-level variation within species may have only a minor influence. We conclude that the higher social tolerance observed in brown capuchins during feeding and foraging contexts can contribute to their broader repertoire of foraging behaviours and foraging traditions.