As my 12-year-old son gets ready to surpass my six-foot height any day (his lip needs a third shave, but he’s apparently in no rush to graduate away from calling me “Daddy”) and as my 8-year-old navigates a peer community that includes mean girls and true friends, gallant young gentlemen (thank you, little boy who offered your frog hat to my daughter backstage during Saturday’s “Honk” matinee) and the pushy ones (I’m thinking of you, little boy who left bruises after poking my daughter in her chest), I’ve been thinking about gender and child development a lot. For some reason, this story caught my fancy.

Young females of the Kanyawara chimpanzee community in Kibale National Park, Uganda, use sticks as rudimentary dolls and care for them like the group’s mother chimps tend to their real offspring. The behavior, which was very rarely observed in males, has been witnessed more than a hundred times over 14 years of study. 

Sticks used as dolls (left) and as tools (right) by young chimpanzees. Photograph courtesy Sonya Kahlenberg. —National Geographic