Expressive Primates Are More Likely to Become Leaders

Researchers from Nottingham Trent University have discovered that primates with more expressive facial movements are more successful within their groups and are more likely to become leaders. The findings are significant for understanding human social behavior, as the researchers suggest that facial expressions in humans also evolved to help maintain social relationships.

Study of Rhesus Macaques

Primatologists studied nine groups of rhesus macaques (Macaca mulatta), each consisting of an adult male, several females, and their offspring. The facial expressions of the dominant male in each group were analyzed using a specially developed coding system called MaqFACS, which tracks the movements of 17 individual facial muscles.

In addition, the researchers assessed the social lives of all 66 monkeys in the groups by measuring how often each pair spent time together and how frequently they engaged in friendly interactions.

Key Findings

The analysis showed that males who displayed a greater variety of emotions had closer and stronger social bonds and were more likely to occupy central positions within the group. In groups with highly expressive males, social connections were distributed more evenly. The researchers believe that pronounced facial expressiveness is linked to a more tolerant leadership style.

This suggests a more inclusive approach to leadership, which promotes group cohesion and reduces social tensions. The ability to form and maintain complex, stable societies provides social primates with many adaptive advantages, which scientists believe played a significant role in human evolution. For this reason, the researchers propose that expressive facial movements evolved to facilitate the building and maintenance of social relationships.

Implications for Human Social Dynamics

The study demonstrates how individual differences in expressiveness can shape the social dynamics of primates, including humans, suggesting that a wider range of facial expressions may be more effective for managing complex social relationships.

Jamie Whitehouse, research fellow at Nottingham Trent University and co-author of the study