Is monogamy natural for humans? This question has long sparked debates among anthropologists and biologists. A recent study, based on the analysis of nearly 200,000 mammalian family trees, has given scientists a fresh perspective on the evolutionary roots of human relationships, placing Homo sapiens alongside other socially monogamous species such as meerkats and gibbons.

Monogamy: Nature or Culture?

The discussion about whether monogamy is an innate human trait or a product of cultural development remains one of the most hotly debated topics in evolutionary anthropology. On one hand, many traditional societies have practiced polygamous marriages. On the other, several evolutionary theories link the shift to monogamy with key features of our species: the development of paternal care, increased brain size, the emergence of complex social cooperation, and the expansion of kinship networks.

However, until recently, there was a lack of concrete data to objectively assess humanity’s place in the biological context. Is Homo sapiens an exception among primates, or a natural link in the evolution of social systems?

A New Study: Analyzing Kinship Ties

Researchers from the University of Cambridge (UK) conducted a large-scale study published in the journal Proceedings of the Royal Society B. They used an unusual but measurable approach: analyzing the composition of siblings—brothers and sisters—in various populations. A high proportion of full siblings (those sharing both parents) indicates a monogamous mating system.

The scientists compiled a database of nearly 200,000 sibling pairs from 103 populations, including ethnographic data from 94 pre-industrial societies and archaeogenetic information from nine ancient burial sites. This approach allowed, for the first time, a comparison of humans not with abstract models, but with real animal species whose mating systems are well defined.

Humans: A Statistically Monogamous Species

The results showed that, on average, 66% of brothers and sisters in human populations are full siblings. This figure matches the level seen in socially monogamous mammals. For example, among meerkats, the rate is 45%, while for gibbons it is 100%. In contrast, among non-monogamous species like chimpanzees, the proportion of full siblings does not exceed 8%.

The Unique Features of Human Monogamy

However, Homo sapiens also displays unique traits. Unlike most socially monogamous mammals, which live in pairs or groups with a single breeding pair, humans form groups where several breeding pairs coexist. Scientists suggest that this structure arose from the need for intensive parental care to raise offspring with energy-demanding brains.

The Significance of the Findings

The authors of the study emphasize that their conclusions do not mean all humans are always monogamous. Rather, at the species level, our social and reproductive system is optimized for forming pairs that produce genetically related offspring. Such kinship structures may have laid the foundation for the unprecedented levels of cooperation, social development, and, ultimately, the emergence of complex cultures and civilizations.