Robin Dunbar

"Dunbar's number" is a theoretical cognitive limit proposed by British anthropologist Robin Dunbar, stating that humans can only maintain about 150 stable social relationships. It suggests that brain size limits the complexity of social groups.

Dunbar calculated this number in the 1990s by correlating the average size of primate brains, specifically the neocortex size, with their social group sizes. He then extrapolated this ratio to the human brain.

Dunbar is a prominent anthropologist and evolutionary psychologist who served as a professor of evolutionary psychology at the University of Oxford. He is also a co-director of the British Academy's Centenary Research Project.

While social media allows people to have thousands of digital contacts, Dunbar's research suggests the cognitive limit of 150 still applies to meaningful relationships. He argues that maintaining deep, emotional connections still requires significant brain capacity.