Much of what we believe about love, sex, and intimacy feels natural and obvious. As if the way we pair off, bond, and desire one another forever is simply “how humans are”. However, some anthropologists have suggested this was not the norm for our species for most of its existence.
One of the most influential modern challenges to our sexual narratives comes from the 2010 book Sex at Dawn, by Christopher Ryan and Cacilda Jethá. Drawing on a broad range of published research in anthropology, primatology and evolutionary biology, the book asks a deceptively simple question: are humans naturally monogamous?
The authors suggest that many of our modern assumptions about exclusivity and pair-bonding are relatively recent concepts, shaped more by the shift away from small hunter-gatherer groups (typically of 150 people) to agriculture about 10-12,000 years ago.
Egalitarian hunter-gatherer groups
For most of human history, our ancestors lived in small, egalitarian hunter-gatherer groups. These societies were highly social, cooperative, and interdependent. Child-rearing was shared (you’ve heard the expression ‘it takes a village to raise a child’), food was shared and, a number of anthropologists argue that there was no pair-bonding as we know it today.
In these groups, sex was not primarily about ownership or exclusivity. It functioned as a social glue, reinforced bonds within the group, reduced conflict, and created a sense of belonging and mutual responsibility. Partible paternity was the norm whereby the assumption was not one but many men were the fathers, which meant children were cared for by the group rather than in a single nuclear unit.
Ryan and Jethá argue that many features of human anatomy support this idea. Humans lack the biological markers typically associated with strictly monogamous species. Instead, our physiology more closely resembles that of species where multi-partner mating is common. This does not mean humans are incapable of pair bonding, but it does suggest that lifelong sexual exclusivity is not hardwired into our biology.
So what changed?
The shift began with the advent of agriculture. When humans started farming and land ownership became central. Property needed to be defended and inherited. Paternity suddenly mattered in a way it had not before. Sexual exclusivity became a mechanism for ensuring only food grown by a man would be used to feed his children. Transfer of wealth also now mattered.
Marriage, as an institution, emerged less as a romantic bond and more as an economic and political arrangement. Sexual fidelity, particularly for women, was enforced to guarantee certainty of paternity. Over time, these structures were moralised and sanctified, becoming embedded in religion, law, and cultural norms. Romantic love as we know it today didn’t really emerge until the 18th century.
This history matters because a significant number of modern struggles around intimacy stem from a mismatch between our evolved social instincts and the structures we now live within. We expect one person to meet needs that were once distributed across a community. Emotional support, sexual fulfilment, companionship, co-parenting, economic partnership, and identity affirmation are all expected to reside within a single relationship. It can be exhausting and almost impossible for some people to achieve.
Monogamy as a strategy, not a destiny
Anthropologists do not suggest that monogamy is wrong or unnatural. Humans are flexible, we adapt to many social arrangements. What they do suggest is that monogamy is a strategy, not a destiny. It works well for some people, some of the time, under certain conditions.
Adopting this view this can soften the shame that often accompanies intimacy challenges. Loss of desire, curiosity about others, the feeling that something is missing, even in a loving relationship. These experiences are often framed as personal failures or moral weaknesses. Anthropology reframes them as innately human traits.
Hunting, gathering, bonding, play, storytelling, cooperation, tight-knit community and mutual care all reinforced intimacy. In modern life, we have become isolated from one another and defined by the nuclear family. When one relationship, or small family unit carries everything, any disruption feels catastrophic.
Sex at Dawn does not prescribe ethical non-monogamy as a universal solution. Rather, it invites curiosity. It asks us to question whether our relationship structures reflect biological truth, cultural habit, or economic history. It encourages us to step back and see if we can separate morality from mechanism.
Perhaps the most useful insight anthropology offers is not about how we should live (because its practically impossible to replicate hunter-gatherer societies in the modern world), but about what we can stop blaming ourselves for.
It simply reminds us that we have always been more complex than the stories we tell ourselves about love.