Neural Basis of Social Hierarchy Identified in Squirrel Monkeys

Recent research published in the Journal of Neuroscience has shed light on the neuroanatomical structures underlying social dominance behaviors in non-human primates, specifically squirrel monkeys. Led by Julie Royo from the Institute of Cerveau, the study examined how specific brain pathways correlate with social hierarchy, aggression, and submission.

The team focused on analyzing brain tracts associated with human emotions, motivation, and memory functions. They evaluated structural brain properties and behavioral measures related to social ranks in 15 squirrel monkeys. Their findings revealed a significant correlation between activity in the uncinate fasciculus, a key brain tract, and social dominance measures. Notably, this correlation was stronger in the right hemisphere of the brain.

These results support the idea that similar neuroanatomical substrates are involved in social hierarchy across different species, including humans. The linkage between the uncinate fasciculus and aggressive behaviors observed in humans suggests an evolutionarily conserved mechanism underlying social dominance.

This research advances our understanding of the neural basis of social behavior and provides insights into the biological foundations of social structures. It highlights the importance of specific brain pathways in shaping social interactions in primates and possibly in humans.

Find out more about this groundbreaking study in the latest issue of the Journal of Neuroscience: DOI: 10.1523/JNEUROSCI.1646-24.2025. For complete details, visit Medical Xpress.