It used to be risky for a scientist to assert that anything about human behavior was innate. To back up such claims, you had to show that the trait was hardwired, unchangeable by experience, and found in all cultures. With that definition, not much is innate, aside from a few infant reflexes such as that cute thing they do when you put one finger into their little hands. If you proposed that anything more complex than that was innate—particularly a sex difference—you’d be told that there was a tribe somewhere on Earth that didn’t show the trait, so therefore it’s not innate.
