Humans Crack the “Top Tier” of Monogamous Mammals, Researchers Say

 A new scientific report has placed humans firmly within the upper ranks of monogamous species, revealing behavioural patterns that align more closely with socially bonded mammals like meerkats and beavers than with the majority of the animal kingdom. According to research conducted by evolutionary anthropologists at the University of Cambridge, humans exhibit a significantly high rate of reproductive monogamy — a finding that challenges long-held assumptions about human mating behaviour.

The study examined genetic and ethnographic data from 35 mammal species, comparing the proportion of full siblings to half-siblings to determine levels of reproductive exclusivity. According to the researchers, species with a higher percentage of full siblings tend to form long-term pair bonds or repeatedly mate with the same partner across reproductive cycles. The analysis placed humans at a 66 percent full-sibling rate, a score that experts described as “comfortably within the premier league of monogamy.”

Eye-witness academic reporting from the research team noted that this figure surpasses well-known cooperative breeders like meerkats, which recorded around 60 percent. However, humans still rank below the study’s top performers, including Eurasian beavers, which reached approximately 73 percent — one of the highest rates observed. The scientists explained that while no species is perfectly monogamous, humans display a strong evolutionary tendency toward stable partnerships and shared parental investment.

Reported by the research group, the study highlights an important distinction between reproductive monogamy — who fathers offspring — and sexual monogamy, which relates to exclusive intimate behaviour. Human societies, shaped by cultural norms, social contracts, and modern birth control, often show more complexity in sexual behaviour than the reproductive data alone can reveal. Still, the high rate of full siblings indicates that across history, most children within human communities shared both parents, suggesting longstanding patterns of partnership stability.

The researchers further stated that the human data was drawn from a broad mix of populations, including ancient burial records from Neolithic and Bronze Age societies as well as information from nearly 100 historic and contemporary communities worldwide. This wide sample shows that the inclination toward pair-bonding is not limited to specific regions or cultures but appears consistent across human evolution.

According to the lead author, understanding these biological patterns does not diminish the cultural flexibility of human relationships. Instead, it provides scientific insight into why long-term bonding, co-parenting, and emotional partnership remain central features of human life. The findings ultimately suggest that while humans may not be the most monogamous species on Earth, we demonstrate a surprisingly strong evolutionary commitment to shared parenting and stable unions — a trait that places our species far closer to monogamous mammals than previously believed.