Why is monogamy in crisis? The animal kingdom could give us some clues | Elle Hunt

Mr.onogamy, you may have heard, is in crisis. Fewer and fewer people are in relationships, and even fewer choose to be in one until death. And even those who have already exchanged vows increasingly seem to be looking for room to maneuver. “Quiet divorce” – mentally ending your union, rather than formally dissolving it – is said to be on the rise, as is “ethical non-monogamy” (ENM) and opening a relationship to include other partners.

This is confirmed by my experience on mainstream dating apps. About one in ten profiles I encounter seem to express a preference for “ENM” or polyamory, or mention an existing wife or girlfriend. The best you can hope for, if you are willing to agree to these terms, is that “primary partner” is actually present in the agreement described.

From Lily Allen’s headline-grabbing album, revealing the gory details of how her lavish marriage unraveled, to Haim’s Relations, a song that expresses restless ambivalence about the simple concept of monogamy itself, pop culture narratives seem equally cynical about our ability to commit to just one person. It’s no wonder it’s difficult to be optimistic about monogamy.

A survey of 1,000 Britons in May last year found that almost a third (31%) believed monogamy was no longer a “realistic” ideal; among 18-24 year olds, this figure rises to 42%. A broader 2023 poll by YouGov found that respondents were almost exactly split on whether humans were “naturally monogamous” or not (with almost a third unsure).

For conservatives, of course, all of this is deeply troubling and speaks to the erosion of good Christian values ​​and the traditional family unit. But what if this difficult consideration of monogamy is not society acting against the natural order, but rather bringing us closer to it?

Late last year, a study from the University of Cambridge highlighted humans’ tendency toward monogamous pairing compared to that of other mammals. This “monogamy ranking,” ranking the proportion of half-siblings in 35 species, puts us comfortably in the top 10 – but not number one.

In fact, humans rank below African wild dogs, mustachioed tamarins, and Eurasian beavers, and with a “monogamy rate” just above that of white-handed gibbons and meerkats. At the bottom of the species studied was the Scottish Soay sheep, reflecting the mating of each ewe with several rams; at the top was the California deer mouse, which, once mated, stays in pairs for life.

So what does this tell us? That we should look to beavers to discover the secrets to a happy, lasting marriage? That traditionalists should adopt the California deer mouse as their mascot for monogamy (it’s admittedly quite cute)? Or that efforts to loosen the marital bond, “ethically” or otherwise, are at odds with the essential nature of our species?

Although the study establishes monogamy as “the dominant mating mode of our species”, its conclusions for us are of course limited, as its author, Dr Mark Dyble, an evolutionary anthropologist at the University of Cambridge, acknowledges. It measures reproductive monogamy, meaning whether an animal procreates with multiple partners, because “in most mammals, mating and reproduction are closely linked.” But humans haven’t been this bonded in a long time, especially since the development of birth control.

Unlike other animals, complex cultural norms have always influenced our approach to sexual and romantic couples. Marriage itself – a relatively recent institution in our species’ 300,000-year-old history, some 4,300 years old – has served to bond women to men (for a long time as property), ensure paternity, and protect the male line.

Christianity began to get involved from the 8th century onwards, and then the state added other layers of baggage, regulating interpersonal unions in order to govern property and inheritance.

Monogamy (reproductive or otherwise) was never guaranteed by any of these permutations of pair bonds. This has certainly not always been uniformly expected: women have historically faced greater social and personal repercussions for infidelity than men.

And focusing solely on the Western approach to mating and reproduction actually obscures enormous diversity among humans. Only a minority of societies worldwide (17%) are strictly monogamous, according to a 2013 study. As a species, we have offered a range of potential approaches to partnership, “from serial monogamy to stable polygamy,” as Dyble notes in the Cambridge study, and each of these has created the conditions for engaged parenting.

This is all the more remarkable in comparison to our primate relatives. Mountain gorillas and chimpanzees rank very low on the “monogamy ranking,” living instead in non-monogamous groups. Yet our own preference for monogamy probably developed from this arrangement.

Considered in this context, the recent questioning of monogamy appears less as an affront to our nature or a threat to our societies, but rather as a new stage in our evolution. Not only has he always tolerated different types of couples; it has always been evolving, negotiated not only between individuals but according to our society and our times. Indeed, given the enormous baggage we packed with our “mating system”, it is somewhat remarkable that it has proven to be both so strong and flexible.

We may only be mammals, but the Cambridge study is a timely reminder of the diversity not only between species, but also within them. The state or health of monogamy cannot be assessed independently of the effects of politics, religion, culture, economics, and – lately, increasingly – technology.

As such, it will continue to evolve. Perhaps not surprisingly, the California deer mouse manages to mate for life: its average lifespan in the wild is less than two years.