The Social Brain Hypothesis

The Social Brain Hypothesis suggests that humans developed larger, more complex brains—especially the neocortex—to manage the demands of social relationships. Because living in groups requires understanding others’ intentions, emotions, and social dynamics, our brains evolved to handle these tasks. This increased mental capacity allowed us to form larger social networks, cooperate more effectively, and navigate social hierarchies. In essence, the complexity of our social environments is thought to be a key driver behind the size and sophistication of the human brain.