Territorial invasion and aggression in young children

Forty black first- and second-grade children were given instructions intended to induce possessiveness for both a designated toy and a play area, along with an opportunity to play with the toy in the area. Each subject then surreptitiously observed an experimental confederate dressed in a clown costume play with either the designated toy or another toy, while either within or outside the child's play area. While observing the invasion, the child had 10 opportunities (trials) to deliver shock to the confederate. Girls who observed the confederate playing with the designated toy delivered more shocks and waited fewer trials to deliver the first shock than did the other girls. Similar effects were produced by the confederate's use of the subject's play area. The manipulations produced no significant effects upon the boys' aggression.