Fathers can breath a sigh of relief. Although biologists have found cuckolding, where one male unwittingly raises the offspring of another male, is common in animal societies, it appears humans are one of the few exceptions.
A recent review published in Trends in Ecology & Evolution on 5th April claims that across modern and ancient human societies, women tended to be faithful to their partners.
Scientists have studied the rate of cuckolding in humans using a combination of genetics and genealogy, and the results consistently indicate that cuckolding is rare, occurring in just 1% – 2% of couples. Surprisingly, the same genetic pattern is evident in genealogies going back hundreds of years, before the advent of modern contraceptive methods, suggesting that extra-marital affairs were rare in ancient societies.
Larmuseau and his colleagues conclude that our ancestors were generally faithful to their partners, and suggest that this may be linked to the costs of being caught. Cuckolding is common in many animal species, particularly birds, and biologists believe these animals benefit by increasing the genetic diversity of their offspring. But for humans, whose offspring need a lot of care to reach adulthood, the potential ramifications of being caught just aren’t worth the benefits of playing away.
The story isn’t quite so simple though – surveys of modern humans have suggested we should expect between 10% and 20% of men to be cuckolded. Larmuseau suggests that this discrepancy represents a relatively recent change in human behaviour; modern contraceptives have liberated women to seek extra-marital affairs without cuckolding their partner.
Want to know more?
- Larmuseau, Matthijs and Wenseleers (2016) Cuckolded Fathers Rare in Human PopulationsTrends in Ecology and Evolution
Featured image by Tomfriedel, used under a creative commons licence from Wikimedia.