It’s no secret that men and women are different — it’s the punchline of a hundred jokes. But does our sex really show in our brains, or is there something else at play?

Gina Rippon, a neuroscientist at Aston University in the U.K. and author of “Gender and Our Brains,” argues that sex doesn’t play nearly as big a role in influencing our brains as we might think. Rather, she says, social cues likely start to influence children at very, very young ages - and it is those cues that account for many of the differences we see.