Overview
- Researchers led by UCLA’s Brian Wood report in PNAS on a decades-long analysis of the Ngogo chimpanzee community in Kibale National Park.
- Coordinated attacks between 1998 and 2008 killed at least 21 neighbors and expanded the group’s range by about 22 percent.
- In the three years after the expansion, births rose from 15 to 37 while mortality before age three fell from 41 percent to 8 percent.
- The authors found no evidence that the post-conflict gains were driven by increased food availability, linking benefits to territorial control.
- The study reframes intergroup violence as potentially adaptive for chimpanzees, while noting that implications for human evolution remain uncertain.