This theory turned out to be wrong. Promiscuity is not limited to males, nor does it only benefit them. In her book Dr. Tatiana’s Sex Advice to All Creation, evolutionary biologist Olivia Judson writes, “From stick insects to chimpanzees, females are hardly ever faithful.” Rather, she asserts, females benefit from promiscuity. A greater number of partners mean higher rates of conception for rabbits and prairie dogs, a higher number of eggs for lizards, and more eggs fertilized for fish.
The point of all this bed jumping is, of course, reproductive fitness, making sure offspring get the best genes on the market. While both sexes may be promiscuous in an attempt to make this happen, there is a slight difference between males and females. Studies show that females mated with the most dominant or genetically successful male do not seek extra pair copulations—if they already have the best, why mess with rest? Males, however, will mate with females of varying status; they lean more toward spreading the seed than aiming high (note our politician’s choices, all of “lower” stature than their own: intern, aide, escort, bathroom stall mate, staffer).
If Mouse, Then Man?
But does this animal evidence tell us anything about human behavior? According to behavioral scientist David P. Barash and psychiatrist Judith Eve Lipton, it may give us clues to why so monogamy is hard. In their book Myth of Monogamy: Fidelity and Infidelity in Animals and People, the authors state that monogamy “goes against some of the deep-seated inclinations with which biology has endowed most creatures, including humans.”
In addition, the size difference between men and women indicates that monogamy isn’t necessarily what we’re programmed to do. In humans and other animals, if males are larger than females, it shows that men had to compete for women; the big and tall males won multiple mating opportunities. The degree of polygyny correlates with the size difference in sexes and since men are larger than women are, this indicates we have been mildly polygynous in our not too distant past.
