Having a Best Friend Makes Chimpanzees Less Stressed About Life

By
Photo: H. Armstrong Roberts/Retrofile/Getty Images

Sometimes, life is just easier with a best friend (or several) — not just because you have someone to help you deal with any big, heavy things that come your way, but for the role they play in the smaller, less consequential moments, too: They remember the things you’ve forgotten. They’re a buffer against loneliness. Starting in your 30s especially, deep, quality friendships may be a good indicator of health and happiness in later years.

And as the Christian Science Monitor recently reported, a study published last week in the journal Nature Communication found that we’re not the only ones who do better with close friends: Chimps, too, are less stressed when they have good buddies within their larger social group.

In the study, the authors set out to evaluate two competing ideas about how and when chimpanzees use social bonds to lessen their stress (friendship, in this case, was defined as “high rates of consistent mutual cooperative and affiliative behaviors” like “grooming, coalitionary support and food sharing” over a period of “several months or years”). The first hypothesis, which the researchers referred to as “social buffering,” holds that that it happens only during highly charged events when the chimps are emotionally aroused; the second, called the “main effects” hypothesis, argues that it’s more constant, with socially bonded chimps generally experiencing less stress in everyday life. To judge the two, the Monitor explained:

The team tested the urine of 17 chimpanzees for stress-related hormone levels in three different scenarios: stressful intergroup encounters, the everyday social interaction of grooming, and a resting period for control. In each type of scenario they tested the individual chimps when a bond partner was present or interacting with them and again when it was a stranger, or an individual without a strong social bond to them.

The verdict: When the animals were around their pals, their stress hormones were lower in all three scenarios — meaning that with chimps, like with us, friendship can be a powerful force for overall well-being. “We believe humans are very special because they can have these interesting relationships between each other that last over the years,” lead study author Roman Wittig, a researcher at the Max Planck Institute for Evolutionary Anthropology, told the Monitor. “This is nothing that’s typically human. The feeling of good friendship, of strong bonds is something that chimpanzees can feel, too.”

Our primate cousins also share some of our less warm and fuzzy social habits: A study published earlier this year in Current Biology found that monkeys, like humans, tend to shed friends as they get older. That’s not as depressing as it sounds, though — as the authors of that paper explained, one explanation is that age makes the animals more risk-averse, which in turn means they just want to spend their time with the companions they already know and trust. The monkeys’ best friends, in other words, are the ones that stick.