Humans, it turns out, behave more like meerkats than chimpanzees when it comes to forming long-term relationships, according to new research comparing monogamy across species.
A scientific “monogamy leaderboard” suggests that humans are around 66% monogamous, placing us far above our great ape relatives and surprisingly close to meerkats — the tight-knit, cooperative mongooses known for sharing family duties.
But humans are still not the most devoted species. The top spot belongs to the California mouse, a small rodent famous for forming lifelong, exclusive partnerships.
“There’s a kind of premier league of monogamy, and humans sit fairly comfortably in it. Most mammals, however, follow a much more promiscuous strategy,” said Dr. Mark Dyble of the University of Cambridge.
Why Pairing Up Evolved
Across the animal kingdom, sticking with one partner can bring major benefits — helping parents raise young, protect territory, and fend off rivals. That’s why social monogamy has independently evolved in many species, including humans.
To measure monogamy, Dr. Dyble analyzed historical and contemporary human populations by comparing ratios of full siblings (sharing both parents) to half-siblings. Similar data was collected for more than 30 mammal species.
The findings:
- Humans: 66% full siblings
- Meerkats: 60%
- Beavers: 73%
- Mountain gorillas: 6%
- Chimpanzees & dolphins: 4%
- Soay sheep: 0.6%
- California mouse: 100%
So despite living in large, complex communities, humans show a level of partner fidelity similar to animals that live in closely bonded group structures.
…but our society works very differently
Dr. Dyble emphasized that similar monogamy scores do not mean similar lifestyles.
Species like meerkats or beavers typically live in colonies or simple pair-living systems. Humans, by contrast, live in multi-male, multi-female societies, where pair-bonds exist within much larger, interconnected social groups.
Dr. Kit Opie of the University of Bristol, who was not involved in the work, said the findings offer another important clue to how monogamy emerged in humans.
“Across geography and across history, the evidence shows that humans tend toward monogamy,” he said. “Our social world looks more like that of chimps or bonobos, yet when it comes to mating strategies, we took a different evolutionary path.”
