Meine Zwei Pfennige
Most of the reasoning is actually quite silly. Men and women are obviously complementary and mating serves to improve the speed of evolution:
Intelligent man mates intelligent women, even more intelligent (read: more dominating in the competition for food with those tigers and wolves) child if made. Or: "strong muscle mates with intelligence", as intel+muscle is required to compete against these extra-sized snakes.
In the endeavour of "rational reasoing" it is always very bad to let yourself be influenced by idealist ideology.
For example, it is quite obvious that men, on average" are more interested in machinery, physics and violence than women. I venture to say this is a genetic thing and it is easy to explain why: Men who instinctively know physics are more likely to hit prey with their spear. That means they can better feed their family and offspring is more likely to survive.
Women, on the other hand are lactating, which means they need to be close to the baby every two hours or so. Naturally, women are on average more competent in handling kids.
So if people stopped to confuse nature with idealist stuff, they might suffer from a smaller number of idealist "disappointments".