Abstract
The social intelligence hypothesis proposes that the demands of social life shape the evolution of cognition, but different aspects of social interactions may be relevant. To test how competitive versus cooperative interactions shape social cognition, we assessed multiple metrics of social cognition in Barbary macaques (Macaca sylvanus, n = 40) and rhesus macaques (Macaca mulatta, n = 60). These closely related species have similar social organization, but diverge in social styles: Barbary macaques are more tolerant, whereas rhesus macaques are more despotic. Monkeys completed a battery of experimental tasks measuring gaze-following (co-orienting with others), knowledge attribution (representing others' underlying knowledge states), goal attribution (interpreting others' actions in terms of underlying intentional goals) and temperament (boldness in response to exploring novelty). While the rhesus macaques were more willing to approach a novel object than were Barbary macaques, both species showed similar success in each social task. However, individual Barbary macaques were more likely to show greater overall proficiency across all social measures combined than were individual rhesus monkeys. Overall, these results indicate that similar social cognitive capacities may evolve in distinct social contexts, and suggest socio-cognitive skills may be relevant for both competitive and cooperative interactions in primates.This article is part of the Theo Murphy meeting issue 'Selection shapes diverse animal minds'.