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Is Monogamy Natural?

The evolution of paternal care.

Is monogamy only an oppressive social institution that puts unnatural constraints on our desires for sexual variety and novelty as well as deep romantic connection with multiple partners?

Certainly, satisfying lifelong monogamous relationships are not easy to achieve given the high prevalence rates of infidelity and divorce and the increasing number of people that don’t even aspire to lifelong monogamy.

And what of the significant percentage of lifelong monogamists who are miserable in their lifelong monogamy? Such individuals may feel that monogamy is a prison that traps them in a permanent arrangement that is sexually frustrating and devoid of emotional intimacy. They stay in it only out of guilt or insecurity while fantasizing about something better.

Maybe it is only wishful thinking that two people could remain reasonably happy in a lifelong sexually exclusive arrangement. The realization of that romantic fantasy does not appear to be the norm of the human condition. Perhaps that romantic fantasy is only realized by a lucky few so that it might be better to live one’s life devoid of idealistic romantic illusions that only set one up for the disappointment of dashed expectations.

Can contemporary evolutionary psychology shed any light on the question of what is natural when it comes to human reproductive strategies?

Looking at monogamy from a cross-cultural perspective suggests that monogamy isn’t a universal norm. Many cultures have legal polygamy as well as prostitution. In fact, most of the patriarchs and kings of the Hebrew Bible had multiple wives and concubines as was customary of ancient Middle Eastern cultures. The early Mormons believed they were just following the Old Testament in practicing polygamy.

The Evolution of Fatherhood

Evolutionary psychology looks for cross-cultural universals when it looks for clues as to the nature of human nature.

One cross-cultural universal appears to be fatherhood. In all known cultures, men have engaged in fathering their children. Yes, on average men don’t invest as much in parenting their children as women do and there are many deadbeat dads who abandon their children.

Raising children, be it fathering or mothering, appears to be part of human nature as both are cross-cultural human universals. Mothering is universal among all mammals as all-female mammals grow a baby in their bodies and then feed the baby with their mammary glands. Curiously, fathering is uncommon among mammals but extremely common among birds. Male birds might build a nest, sit on the eggs, and then help feed or defend the newborn chicks. In birds, fathering is only present in birds that are monogamous if perhaps only for a single breeding season.

A cross-species analysis suggests that fathering only evolves when there is monogamy. Why is that? The answer appears to be paternity certainty. It only adds to a male’s reproductive success if he can be reasonably confident that he is raising his own children rather than another male’s children. So, for fathering to evolve at least the females need to be faithful so the males possess paternity certainty.

But why then should males be monogamous if they could be more reproductively successful by inseminating multiple females? The answer seems to be that it only pays for females to be monogamous if females possess some certainty that the males will stick around to help nurture and protect the offspring. There’s no benefit for females being sexually exclusive when the males are practicing a mating strategy of "love them and leave them," requiring single mothers to fend for themselves without paternal assistance. Bi-parental care would only evolve if both males and females were willing to practice monogamy.

Are Humans Good at Monogamy?

Given the universality of fathering and bi-parental care among humans, it would seem that humans have evolved in a monogamous direction. There is an innate tendency towards monogamy; to engage in sexually exclusive romantic pair-bonding for bi-parental care.

The problem is that just because we possess innate monogamous tendencies doesn’t mean we no longer possess non-monogamous tendencies as well (i.e. desires for multiple partners) or that just because we have monogamous desires and fantasies, we also possess the personality dispositions and interpersonal skills to be successful at it.

Many of us are failed monogamists in that we aspire to a lifelong and satisfying monogamous relationship but because we aren’t good at it, we don’t achieve what we most desire in life. People who are securely attached, authentic, and high in empathy with good communication skills tend to be better at monogamy than people that are insecurely attached, high in narcissism, fake, and low in empathy with poor communication skills.

So, from the perspective of evolutionary psychology, monogamy is natural because fathering is natural in the human species and fathering only evolves with sufficient sexual exclusivity to allow for paternity certainty for men and sufficient resource provision certainty for women.

Nevertheless, we still possess strong non-monogamous desires as well because it can still be adaptive to mate with the partner with the best genetic material or the most resources even if they don’t stick around or you have to share them with others. In addition, to be good at monogamy it helps to possess certain personality dispositions and interpersonal skills. Just because you have a deeply-seated instinctive desire for something doesn’t mean you will fulfill that desire if you approach actualizing it in a misguided way like being more game-playing than authentic in your love life.

Of course, we don’t all have to be successful monogamists if it’s not something you really aspire to or are good at, even if it’s something you would like. Some of us might aspire to be successful at consensual nonmonogamy and that, too, requires certain personality dispositions and interpersonal skills like overcoming jealousy and insecurity about consensual partner sharing. And some of us that are monogamists at heart might have to accept that we just aren’t that good at it despite our best efforts, and that’s OK. We all need to develop self-compassion for our human limitations. And just maybe some of us will finally figure out how to succeed at monogamy if we just don’t give up on trying to learn from our mistakes.


Josephs, L. (2018) The Dynamics of Infidelity: Applying Relationship Science to Psychotherapy Practice. American Psychological Association: Washington, D.C.

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