A new study by anthropologists at Northwestern University suggests that if a male interacts with and takes care of gorilla infants a lot, he is likely to have more reproductive success, reports The Atlantic. The study’s subjects? Male gorillas, who many assume don’t experience tenderness and affection the way female gorillas do. After looking at hundreds of hours of observations collected in the early 2000s by the Dian Fossey Gorilla Fund, researchers came to a startling conclusion: the male gorillas that spent the most time looking after another gorilla’s infant were likely to have 5.5 times as many children of their own, in comparison to the male gorillas who didn’t spend time babysitting.
Gorilla groups, which usually have around nine males each, have a ranking system when it comes to who is most powerful or who is more in charge. Researchers observed male gorillas at any place in the hierarchy were able to produce more offspring after spending time playing with the infants of the group. Weirder still, why would a male gorilla pay attention to a child that wasn’t theirs? Why would they attempt to influence the life of a gorilla that wasn’t carrying on their lineage?
Well, it was also observed that the female gorillas found the male gorillas babysitting and interacting with infants attractive. The females may be considering that if they mate with someone who they see is good with babies, he will be good with his own child and give that offspring a better chance at life. According to Science Daily, the researchers are wondering if the behavior in the gorillas could say something about our own species.
“Mountain gorillas and humans are the only great apes in which males regularly develop strong social bonds with kids, so learning about what mountain gorillas do and why helps us understand how human males may have started down the path to our more involved form of fatherhood,” said Stacy Rosenbaum, lead author of the study. Rosenbaum, who is currently a post-doctoral fellow in anthropology at Northwestern, is also pondering if hormones play any part in this behavior.
“We’re working on characterizing these males’ hormone profiles across time, to see if events such as the birth of new infants might be related to their testosterone levels,” she explained. “We’re fortunate to have data that span many years of their lives.”
When a human becomes a father, their testosterone levels lower. If this were to happen to male gorillas, that would make it harder for them to compete with the other males in their group, meaning there has to be some kind of positive outcome for men to want to babysit, such as attracting a mate. When we look at our evolution, we wouldn’t expect human males to play a role in paternal care. They do, though, and so researchers believe that further studies on the gorillas will help us to understand why.