The play partners of immature baboons

In a troop of free-ranging baboons, infants played predominantly with each other, and played most with the infant of the highest-ranking female in their mothers' subgroup. The frequency of infant play appeared to be affected both by age and by the number and ages of other infants in the troop. Juveniles and subadults played more with their siblings than with other animals of their siblings' age. Juvenile and subadult females played primarily with infants, and played most with infants whose mothers ranked higher than their own. Juvenile and subadult males played most with like-sexed peers. The distribution of play partners among immatures illustrates how demographic and maturational factors, as well as those related to kinship, may reinforce or counteract one another during development.