Male baboons get health benefits from platonic friendships with females

A GROWING body of research hints that for nonhuman primates, purely platonic relationships come with big benefits.

A study that draws on decades of research about baboons is adding to a pile of cross-species evidence of the protective power of friendships.

Researchers have been watching how baboons in the Amboseli basin of southern Kenya interact with one another since 1971. They used decades of observations and a mathematical model to explore if social interactions between the animals predict their survival. Their research was recently published in the journal Philosophical Transactions of the Royal Society B: Biological Sciences.

Male baboons don’t just interact with females when they want to mate: They also engage in platonic grooming, a behavior known as a way for primates to bond and destress.

Researchers found that both males and females were more likely to survive in any given year if they had close friendships. Males with baboon besties were 28 per cent more likely to survive at any age.

That’s similar to humans. But unlike humans, whose survival is linked in part to socioeconomic status, a higher place on the social pecking order didn’t help baboons. The most dominant males were 13 per cent more likely to die at any given age than the least dominant ones.

The scientists believe this may be related to the big trade-offs male baboon bodies make for the traits that guarantee social status. Male baboons with high testosterone have a reproductive advantage, but the hormone suppresses their immune system. They age faster, too.

So do social ties actually cause longer lives, or is it just a correlation? “We still don’t know,” says Susan Alberts, chair of the Evolutionary Anthropology Department at Duke University, in a news release. The researchers say more work needs to be done to tease out the potential connection. “It’s one of the most wonderful black boxes in my life.”