While I agree I think it's safe to say that in mammals the differences are pretty district, at least physically. A male cannot generally carry, birth, or initia

While I agree I think it's safe to say that in mammals the differences are pretty district, at least physically. A male cannot generally carry, birth, or initially feed offspring. This gives females a very distinct reproductive function over relatively long periods of time. It seems natural that evolution would enhance traits in females (physically and cognitively) that would make them best at that task.