In the age of Facebook and Twitter, it's instructive to know just how many friendships the human brain is really able to handle. The answer? 150, according to a new study published by Robin Dunbar, professor of Evolutionary Anthropology at Oxford University. His research reveals 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, or how larger our Facebook networks. Dunbar, in case you're wondering, derived the limit from studying social groupings in a variety of societies -- from neolithic villages to modern office environments.