Beefed up immune systems are apparently so necessary to the survival of polygamous creatures, that individuals of these species are born with high white blood cell counts and maintain them throughout their adult lives, even if they remain virgins. The same immune system that repels invaders is charged with surveillance of the body for internal interlopers too, including renegade cancer cells. In other words, the price for promiscuity is the need to maintain a supercharged immune system, without which a group risks wholesale death from infection. AIDS, for instance, is a scourge among the segments of human society that are least restrictive in numbers of sex partners, including prostitutes and the gay bath house subculture that used to indulge in, unprotected, indiscriminate sex. So, men, I m sorry.
Women are right.
Our low levels of white blood cells seem to indicate that we humans really are built for monogamy. As the parent of teens, I know it could be worse. Not only might God have condoned promiscuity, but He might have left out the Commandment about honoring your father and mother.