"Society works not because we have consciously invented it, but because it is an ancient product of our evolved predispositions. It is literally in our nature."

Next Quote

Because men, compared to male chimps, have such relatively small testicles (large testicles indicate a species where many males mate, one after the other, with the same female), we might guess that promiscuous societies were uncommon in the immediate human past.

— Carl Sagan