Why did you write this book?
Like many parents, I was fascinated by the differences between my daughter and sons. But as a neuroscientist, I was curious how these differences are reflected in their brains. And if there are differences between boys’ and girls’ brains, what causes them—nature or nurture? I’ve also always been fascinated by the degree to which our personalities and abilities are shaped by innate factors, such as genes and hormones, versus environment—learning and experiences. Sex differences are a perfect distillation of this question, because there are obviously inborn biological differences between boys and girls, as well as deep differences in the culture boys and girls grow up in. I relished the chance to dig into the actual scientific data on the comparative roles of nature and nurture in creating sex differences in children’s brains and behavior.