Monogamy might be the most stupefying force in the history of humankind. Intelligence is distributed on a bell curve. If you permit the idiots to reproduce at the same rate as the geniuses, very soon we have eight billion idiots and only a few geniuses. Alternatively, if the geniuses are permitted to reproduce in proportion to their value to society, you get a better society.
Hmm, ever wonder why Mr. Tesla enjoyed getting busy?