He showed 3 groups of children a film.
Group A - adult acting aggressive to doll.
Group B - adult acting aggressive to doll, was rewarded with sweets by another adult.
Group C - adult acting aggressive to doll, was told off by another adult.
Afterwards, each child in a playroom with a bobo doll, reactions were recorded.
Group C = less aggressive to doll
Group A + B = little difference in aggressiveness, showed they were less influenced by the reward.
Follow up experiment = asked to demonstrate how doll was attacked. reward given. little difference between groups, showed could all imitate seen behaviour.