A new study finds that intelligence and cooperative behavior in humans can co-evolve to solve the problem of collective action in groups and to overcome the costs of having a large brain.

Warfare not only hastened human technological progress and vast social and political changes, but may have greatly contributed to the evolutionary emergence of humans’ high intelligence and ability to work together toward common goals, according to a new study from the National Institute for Mathematical and Biological Synthesis (NIMBioS).