No Monkey, No Cry

Those who know her best describe Sylvia as closed off and even “disdainful.” So it was a shock that the 23-year-old baboon turned to her companions for support when her daughter and best grooming partner, Sierra, suffered a fatal encounter with a lion. Sylvia’s observed behavior – seeking comfort from social contact – was humanlike. Research has uncovered shared biological underpinnings for this social behavior in baboons and humans.

According to researchers at the University of Pennsylvania, baboons experience bereavement much the way humans do, with a rise in hormones called glucocorticoids. The findings of biologists Ann Engh and Dorothy Cheney, and University of Pennsylvania psychology professor Robert Seyfarth, were published in Proceedings: Biological Sciences of the Royal Society. Their research shows that while stress causes an elevation in these hormones, baboons can lower their glucocorticoid levels through friendly social contact and expanding their social network.

“Females are particularly affected by stress,” says Engh. In the study, the team tracked glucocorticoid levels at critical times, most notably when the baboons’ lives, the lives of their offspring, or their social rankings were at risk. “Our findings do not necessarily suggest that baboons experience grief like humans do, but they do offer evidence of the importance of social bonds amongst baboons,” Engh reported to the the University of Pennsylvania. “Like humans, baboons seem to rely on friendly relationships to help them cope with stressful situations.”