A Cambridge University study has placed humans 7th out of 35 mammal species for monogamy, showing we are relatively loyal compared with much of the animal kingdom. Humans ranked above meerkats and gibbons, but Eurasian beavers and moustached tamarins came out ahead, with beavers showing a 72% rate of full siblings compared to the human average of 66%.
Researchers analysed genetic data to compare how often offspring share both parents — a sign of monogamous mating. At the bottom of the list were chimpanzees, bottlenose dolphins and Soay sheep, where half-siblings were far more common.
Scientists say human monogamy is unusual given our close relatives are mostly promiscuous. The behaviour may have evolved through the benefits of parental care, though cultural and religious norms also strongly shape human relationships.
Humans sit firmly in the “monogamous league” — just not quite as devoted as beavers.
