Support from family and friends significantly reduces stress in wild chimpanzees – during conflicts with rival groups and during everyday affiliation

In humans and other social animals stress is associated with poor health and high mortality. These negative effects can be buffered by receiving social support from relatives or friends. However, the mechanisms responsible for this effect remain largely unknown. A team led by Roman Wittig, Catherine Crockford and Tobias Deschner from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has studied how wild chimpanzees cope with stressful and non-stressful situations when a close bond partner is present or absent. They measured the animals’ urinary stress hormone levels during episodes of intergroup conflict, grooming and resting and found that the support of a friend significantly reduced the chimpanzees’ stress hormone levels, especially in situations of conflict. But even during affiliative activities with the bond partner stress levels were generally lower. Daily supportive actions by friends and family maybe key to regulating stress hormone activity, and thus the negative effects of stress, a finding with potential medical implications for humans.