Gorilla Social Lives: A Complex Equation of Costs and Benefits

A 20-year study of 164 wild mountain gorillas reveals the complex interplay of costs and benefits associated with sociality. The study found that the advantages and disadvantages of social bonds varied depending on group size and sex. Friendly females in smaller groups experienced less illness but fewer offspring, while those in larger groups had higher birth rates but more illnesses. Males with strong social ties tended to be sicker but less prone to injuries from fights. This research highlights how the diversity of social strategies in social animals, including humans, arises from the trade-offs between costs and benefits.