Boys Will Be Boys and Girls Will Be Girls—Even When They're Chimps

Awww, young female chimps play with dollies too. According to a study in the Dec. 21 issue of the journal Current Biology, young chimpanzees appear to play differently depending on their gender—just like our little ones. Researchers who spent 14 years observing a chimpanzee community in a national park in Uganda found that both male and female chimpanzee youngsters play with sticks, but females do so more often and sometimes treat the sticks as would mothers caring for their infants.

The findings suggest that the consistently greater tendency across all human cultures for girls to play with dolls is not just the result of sex-stereotyped socialization, but is also influenced by biology, the study authors said.

"This is the first evidence of an animal species in the wild in which object play differs between males and females," study author Richard Wrangham of Harvard University said in a journal news release. "We thought that if the sticks are being treated like dolls, females would carry sticks more than males do and should stop carrying sticks when they have their own babies. We now know that both of these points are correct."

Another interesting point is that this is the first time that stick-carrying as a form of play has been reported in chimpanzees, the study authors noted.

"This makes us suspect that stick-carrying is a social tradition that has sprung up in our community [of chimpanzees] and not others," Wrangham stated in the news release.

If further research shows that this behavior is unique to this community, "it will be the first case of a tradition maintained just among the young, like nursery rhymes and some games in human children," he said. "This would suggest that chimpanzee behavioral traditions are even more like those in humans than previously thought."