The popularity of television shows such as Sister Wives and Big Love that feature polygamous families reveals an enduring human fascination with a social arrangement that is generally frowned upon by most modern societies.
Is it possible that we are drawn to these shows because they tap into our ancestral past?
Polygamy was a Common Arrangement in Human History
Our understanding of the murky evolutionary origins of human social organization and mating patterns is far from settled, but it is the consensus of scholars who study this topic that most early human groups utilized a polygamous (or at least serial monogamist) arrangement where dominant, high status men took multiple wives.
The things that contributed the most to a man’s status in these early human groups were his skill as a hunter and as a warrior, but a man's social standing was also dependent upon how believable his threats of physical violence were. Men who maintained a reputation for being tough customers were better able to hang onto their status—and therefore their mates.
Whenever I discuss human mating systems in my classes, and before I delve too deeply into the topic, I ask the class if polygamy is a better deal for men or for women.
The question is usually greeted by suspicious smiles as if the students smell a trap baited by a trick question. Eventually, they reluctantly respond in unison with something that sounds like “Duh—men!”
I then follow-up by asking, “Which men?”
It quickly becomes apparent that when polygamy comes up, most students are thinking only of the high status guy who is adding yet another desirable woman to his harem, and that they are also thinking about the women who are forced to share him with each other.
No one, however, seems to be thinking about the great many men who get shut out of the mating game entirely under this sort of polygamous system.
Polygamy Creates Intense Competition Among Men
Sexual competition for mates has always been more intense for males than for females, especially in ancestral polygamous societies. The stakes were very high in this environment, as the winners of the competition between men would come away with the greatest number of women (and the most desirable women). The losers ran the risk of genetic annihilation by their failure to successfully win the status and resources necessary to attract mates.
Consequently, powerful men have always enjoyed greater sexual access to women than men lower in the pecking order, and stereotypical male traits such as ambition, competitiveness, and violence can be traced to this grim struggle for status and mates among men.
So, if you have a society with an approximately equal number of “marriageable” men and women, each time one man takes on a new wife, another man goes without a mate completely.
Monogamy appeared relatively late in human history when the size of human groups became large enough that one could not know everyone else in the group personally, so stability and order became much more complicated to maintain. Under these circumstances, a society could be completely undermined by having a large number of desperate, mateless men on the loose; monogamy may have become the vehicle for spreading women out among men in a way that diffused violence and lawlessness. Indeed, even today, unmarried men are overrepresented as both perpetrators and victims of violent crimes such as assault and homicide.
This line of reasoning leads me to conclude that polygamy was a good situation for a very few privileged men, but an absolute nightmare for most.
And also think about this from the female perspective: Would it be more desirable to be the second or third wife of a powerful, influential man with great genes and bountiful resources, or the only wife of a loser?