Chimpanzee 'Civil War' Study Reveals Evolutionary Insights into Human Conflict

A violent split among Uganda's Ngogo chimpanzees has persisted for nearly a decade, with Western group members killing seven adult males and 17 infants from the Central faction since 2018. Researchers documented the initial hostile encounter on June 24, 2015, when Western chimpanzees approached Central members in Kibale National Park, leading to unprecedented fighting. Primatologists Aaron Sandel from the University of Texas at Austin and John Mitani from the University of Michigan observed the escalation, which resulted in two distinct groups emerging by 2018. The conflict represents the bloodiest division ever recorded among wild chimpanzees, involving the largest-known community of nearly 200 individuals. While the Eastern cluster has allied with the Central group without participating in violence, Central males have not retaliated despite outnumbering their Western counterparts. Published on April 9 in the journal Science, the study suggests such extreme internal conflicts occur approximately once every 500 years among chimpanzees. Researchers speculate that group size and competition for resources may have dissolved social cohesion, though the exact trigger remains unknown. The findings offer potential parallels to human ancestral violence, indicating that ideological divisions are not necessary for warfare to emerge.