Overview
- On average, about 66% of human offspring are full siblings, indicating predominantly monogamous reproduction across cultures and eras.
- Humans place 7th of 35 mammals in the ranking, between the Eurasian beaver at roughly 73% and the white‑handed gibbon at about 63.5%.
- The analysis aggregates genetic kinship data from more than 100 human populations and 34 other mammals, using sibling proportions as a coarse proxy for monogamy.
- Several species score higher than humans, including the California mouse at 100%, African wild dog at 85%, Damaraland mole‑rat at 79.5%, Ethiopian wolf at 76.5%, and European beaver at 72.9%.
- Most primates register low values—chimpanzees around 4%—and only about nine percent of mammal species qualify as monogamous by this measure.