WE may be able to amass 5,000 friends on Facebook but humans’ brains are capable of managing a maximum of only 150 friendships, a study has found.

Robin Dunbar, professor of Evolutionary Anthropology at Oxford University, has conducted research revealing that while social networking sites allow us to maintain more relationships, the number of meaningful friendships is the same as it has been throughout history.

Dunbar developed a theory known as “Dunbar’s number” in the 1990s which claimed that the size of our neocortex — the part of the brain used for conscious thought and language — limits us to managing social circles of around 150 friends, no matter how sociable we are.

Dunbar derived the limit from studying social groupings in a variety of societies — from neolithic villages to modern office environments. He found that people tended to self-organise in groups of around 150 because social cohesion begins to deteriorate as groups become larger.

“There is a big sex difference though ... girls are much better at maintaining relationships just by talking to each other. Boys need to do physical stuff together.”

Dunbar’s study is due to be published later this year.

ht: @mike_elgan