Right—I perhaps should have been clearer about this in my own post. It's definitely a spectrum, not a binary, though I'm not at all sure the distribution is nor

Right—I perhaps should have been clearer about this in my own post. It's definitely a spectrum, not a binary, though I'm not at all sure the distribution is normal (ie, a bell curve). I don't have any actual sources on that, though, and I'd be very intrigued to see a scientific study giving a population-level distribution of those traits in particular.