He had a large sample of toddlers half female half male and setup a lab experiment. The experiment consisted of two conditions, in the first condition half the toddlers observed an aggressive model playing in a room ie. hitting a bobo doll and the second condition had the other half observing a non-aggressive model playing. There was a third condition in which no observation was taken place, this was the control group. The children were then put in their groups into the same room and observed for 20 minutes.