Humans have been ranked 7th out of 35 mammal species for monogamy in a new Cambridge University study. Using genetic data to compare rates of full vs half-siblings, researchers found humans averaged 66% full siblings, placing us alongside typically monogamous animals — though Eurasian beavers scored higher at 72%.
At the top sits the California deermouse, while chimpanzees, dolphins and mountain gorillas ranked near the bottom due to highly promiscuous mating systems. The study shows that, unlike our close ape relatives, humans evolved toward pair bonding — a rare shift among mammals that may be linked to the rise of paternal care.
Researchers note that cultural and religious norms heavily influence human relationships, meaning monogamy is practiced differently across societies. Even so, in the animal kingdom rankings, we still make the monogamy top tier — just behind the beavers.
