S heldon Cooper presented The Big Bang Theory fans with an intriguing mystery when he mentioned having exactly nine friends, ...

And how many are in each layer will depend on your personality, too. “Where we sit on the introversion-extroversion spectrum greatly influences the number of friends we have,” says Alderson.

You know, I don’t have very many — none of us really have very many friends,” Affleck told reporters for People. “You don’t need a million friends; you need a few good ones.