Final answer:
Children in the Bobo Doll study displayed less aggression when they observed aggressive models being punished, illustrating vicarious reinforcement in observational learning.
Step-by-step explanation:
In the follow-up study to the original Bobo Doll experiment by Bandura, vicarious reinforcement was observed when children behaved less aggressively after witnessing aggressive models being punished. Bandura's research into observational learning showed that children are less likely to imitate a model's behavior if they see the model being punished. This punishment can decrease the likelihood that the observer will replicate the aggressive behavior.