Facial expressions used by children in a conflict situation.

72 pairs of kindergarten children were each given a brief play session involving an object with which only 1 child could play at a time. Facial expressions used by children defending their possession of the object were studied. Results showed a relationship between the facial expressions a child used and both his own subsequent behavior and that of his partner. "Agressive" facial expressions were associated with persistent attempts by the expressers to maintain access to the disputed object. Percipients of aggressive expressions were relatively hesitant about making a new attempt to take the object from the expresser. 1 nonaggressive expression was also followed by percipient hesitancy. The relationship of the aggressive expressions to both primate threat displays and human facial expressions of emotion is discussed.