Summary: A new study challenges the belief that larger groups reduce cooperation, showing instead that flexible social connections enhance teamwork. Researchers found that in a prisoner’s dilemma game, participants in bigger groups cooperated more frequently, despite memory limitations.

Brain scans revealed that when memories of past interactions were unclear, participants relied on prosocial instincts to guide behavior. Key brain regions, including the prefrontal cortex and nucleus accumbens, helped balance memory, reward, and decision-making.