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Abstract Characterizing individual differences in cognition is crucial for understanding the evolution of cognition as well as to test the biological consequences of different cognitive traits. Here, we harnessed the strengths of a uniquely large, naturally‐living primate population at the Cayo Santiago Biological Field Station to characterized individual differences in rhesus monkey performance across two social cognitive tasks. A total ofn = 204 semi‐free‐ranging adult rhesus monkeys participated in a data collection procedure, where we aimed to test individuals on both tasks at two time‐points that were one year apart. In thesocioemotional responses task,we assessed monkeys' attention to conspecific photographs with neutral versus negative emotional expressions. We found that monkeys showed overall declines in interest in conspecific photographs with age, but relative increases in attention to threat stimuli specifically, and further that these responses exhibited long‐term stability across repeated testing. In thegaze following taskwe assessed monkeys' propensity to co‐orient with an experimenter. Here, we found no evidence for age‐related change in responses, and responses showed only limited repeatability over time. Finally, we found some evidence for common individual variation for performance across the tasks: monkeys that showed greater interest in conspecific photographs were more likely to follow a human's gaze. These results show how studies of comparative cognitive development and aging can provide insights into the evolution of cognition, and identify core primate social cognitive traits that may be related across and within individuals.
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This content will become publicly available on June 26, 2026
Tolerant and despotic macaques show divergent temperament but similar theory of mind
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 measuringgaze-following(co-orienting with others),knowledge attribution(representing others’ underlying knowledge states),goal attribution(interpreting others’ actions in terms of underlying intentional goals) andtemperament(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’.
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- Award ID(s):
- 1944881
- PAR ID:
- 10657549
- Publisher / Repository:
- Philosophical Transactions B
- Date Published:
- Journal Name:
- Philosophical Transactions of the Royal Society B: Biological Sciences
- Volume:
- 380
- Issue:
- 1929
- ISSN:
- 0962-8436
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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