Cambridge Study Places Beavers Above Humans in Monogamy Rankings
Researchers at the University of Cambridge have compiled a fascinating "monogamy league table" that ranks various mammal species based on their reproductive fidelity. The study, which analysed the proportion of half and full-siblings across 35 different species, places humans comfortably within the top ten but notably below several other animals including African wild dogs, moustached tamarins, and Eurasian beavers.
This intriguing research emerges at a time when traditional monogamous relationships appear to be undergoing significant transformation in human societies. With fewer individuals choosing to enter long-term partnerships or marriage, and concepts like "ethical non-monogamy" gaining traction, the Cambridge findings provide a unique evolutionary perspective on contemporary relationship trends.
The Monogamy League Table Results
The comprehensive study revealed that California deermice occupy the top position with lifelong pair-bonding, while Scottish Soay sheep ranked at the bottom due to their promiscuous mating patterns. Humans found themselves positioned just above white-handed gibbons and meerkats in the rankings, with a monogamy rate that surprised many observers.
Dr Mark Dyble, the evolutionary anthropologist who led the research at Cambridge, emphasised that the study specifically measures reproductive monogamy - whether animals procreate with multiple partners. "In most mammals, mating and reproduction are tightly linked," explained Dyble, "but humans have not been bound by this connection for a considerable time, particularly since the development of effective birth control methods."
Cultural Influences on Human Pair-Bonding
Unlike other mammals, human approaches to romantic and sexual partnerships have always been profoundly influenced by complex cultural norms and societal structures. The institution of marriage, which represents a relatively recent development in our species' 300,000-year history at approximately 4,300 years old, originally served to establish paternity, protect male lineage, and essentially bind women to men as property.
Christianity began shaping marital norms from the eighth century onward, with state institutions subsequently adding further layers of regulation primarily focused on governing property and inheritance matters. Throughout these historical permutations, monogamy has never been universally guaranteed or consistently expected across different societies and time periods.
Global Diversity in Relationship Structures
A 2013 study revealed that only about 17% of global societies practice strict monogamy, highlighting the tremendous diversity in human approaches to partnership. As Dr Dyble notes in the Cambridge research, our species has developed a remarkable range of relationship models "from serial monogamy to stable polygamy," while consistently creating conditions conducive to committed parenting across these varied structures.
This adaptability becomes particularly striking when compared with our primate relatives. Mountain gorillas and chimpanzees, which rank very low in the monogamy league table, typically live in non-monogamous social groups. Human preferences for monogamy likely evolved from similar ancestral arrangements, making our current relationship diversity part of a long evolutionary continuum.
Contemporary Relationship Trends and Evolutionary Context
Recent surveys indicate shifting attitudes toward traditional monogamy. A May 2023 survey of 1,000 British respondents found that nearly one-third (31%) no longer consider monogamy a realistic ideal, with this figure rising to 42% among 18- to 24-year-olds. A larger YouGov poll conducted the same year revealed that respondents were almost evenly divided on whether humans are naturally monogamous, with approximately one-third expressing uncertainty.
These changing perspectives, reflected in popular culture through works like Lily Allen's confessional album about her failed marriage and Haim's song "Relationships" expressing ambivalence about monogamy, represent not necessarily a rejection of human nature but potentially another evolutionary adaptation. The Cambridge study serves as a timely reminder that relationship structures cannot be evaluated separately from the influences of politics, religion, culture, economics, and increasingly, technology.
As Dr Dyble's research demonstrates, while monogamy represents the dominant mating pattern for our species, the tremendous cultural baggage associated with human "mating systems" has created remarkably flexible and load-bearing structures that continue to evolve alongside societal changes. Perhaps the California deermouse's lifelong pairing seems less remarkable when considering its average wild lifespan of less than two years, while humans navigate relationship complexities across decades of changing social landscapes.
