Abstract
Sex‐related behavior in immature wild mountain gorillas consisted primarily of gental stimulating episodes in which one animal thrusted against the body of another. Whereas the immature males used the D‐V position predominantly, a single immature female that performed as an actor used the V‐V position exclusively. All episodes of genital stimulating behavior originated in the context of play and most actors were older (and larger) than recipients of such behavior. The data support the findings of earlier research but suggest that genital stimulating behavior among immature gorillas occurs more frequently than previously thought. These results in conjunction with comparable data on pygmy and common chimpanzees and orangutans suggest that genital‐stimulating behavior by immature individuals is a species‐typical phenomenon in the behavioral development of the great apes.