U. PENN (US)—Female baboons who have strong social relationships with other females, especially their daughters, are more likely to give birth to babies who survive to adulthood than babies raised by less social mothers.
“Females who raise offspring to a reproductive age are more likely see their genes pass along, so these findings demonstrate an evolutionary advantage to strong relationships with other females,” says researcher Dorothy Cheney, biology professor in Penn’s School of Arts and Sciences. “In evolutionary terms, social moms are the fittest moms, at least when it comes to baboons.”
The improved survival rate may be linked to daily activities such as grooming, which lowers cortisol, or stress hormones, in baboons.
Cheney, along with Penn professor of psychology Robert Seyfarth and other researchers, studied 17 years’ worth of records on more than 66 adult female baboons in the Moremi Game Reserve, a 2,000-square-mile national park in Botswana. They found the strongest social bonds exist between mothers and adult daughters—which are three times greater than those between sisters, and 10 times stronger than relationships with other females.
“The benefit comes not from being wildly social. It’s about having close social bonds,” says Cheney, who runs the Moremi baboon-tracking project with Seyfarth.
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