Written by: Jill Heagerty

I’ve heard both sides: we’re biologically meant to mate with many partners and that monogamy does not work for humans, and that after the lust and falling in love stages there forms an attachment between partners that leaves their brains more satisfied than any previous stage. So which is it? Are we supposed to be with one person forever, or are we meant to have various partners to quench sexual appetites?

The argument for polygamy lies with the two facts concerning our genetic similarities to polygamous apes and the men in our species being taller than women. We are most closely related to chimpanzees and bonobos, naturally promiscuous mammals. Men in these species want to “spread their seed”, something men in our species also desire, so they mate with as many females as they can to produce maximum offspring. If our DNA resembles these primates, are we living by the wrong sexual rules? Are we only monogamous because culture demands it, and we’re actually going against our true nature? The other supporting evidence for polygamy is attributed to the height and weight differences between men and women. In both primate and non-primate species, the more disparity there is in the sizes between the genders, the more promiscuous the species is. On average, men are 10 percent taller and 20 percent heavier than women, suggesting that while humans are not meant to mate as much as chimpanzees or bonobos, we are not meant to be solely monogamous.

Monogamy’s side comes from the pleasure hormones released in the brain when we form deep attachments to one partner and the evolutionary benefit for raising children. There are three stages to long-term mating: lust, falling in love, and attachment. The first stage lust is caused by a general increase in estrogen and testosterone levels. Falling in love releases specific neurotransmitters in the brain associated with pleasure, including pheromones, dopamine, norepinephrine, and serotonin. These hormones act similarly to amphetamines, giving us intense feelings of excitement. The last stage is attachment, releasing oxytocin and vasopressin in the brain, giving a constant satisfaction that the other pleasure inducing hormones don’t. It’s not possible for humans to be high on love all the time, so the body gives pleasure that can endure. The purpose of oxytocin and vasopressin is to keep families together, an evolutionary benefit to children in today’s society. In the beginning of time it was okay for males to have multiple mates because children were raised in tight knit communities, but with single families there needs to be two partners providing support for children to flourish.

There is no clear cut answer. Whether we are monogamous or polygamous lies in individual needs, as there are arguments to support both sides. The question becomes, do you want the crazy rush of passion associated with having many partners for life or do you want the quiet satisfaction of having one person to drive you crazy?