Observational Learning
In a set of well known experiments, called the "Bobo doll" studies, Bandura showed that children (ages 3 to 6) would change their behavior by simply watching others.
Three groups of children watched a film in which a child in a playroom behaved aggressively (e.g., hit, kick, yell) towards a "bobo doll." The film had three different endings. One group of children saw the child praised for his behavior; a second group saw the child told to go sit down in a corner and was not allowed to play with the toys; a third group (the control) group saw a film with the child simply walking out of the room. Children were then allowed into the playroom and actions of aggression were noted. The results can be viewed Here.
Bandura and his colleagues also demonstrated that viewing aggression by cartoon characters produces more aggressive behavior than viewing live or filmed aggressive behavior by adults. Additionally, they demonstrated that having children view prosocial behavior can reduce displays of aggressive behavior (Huitt & Hummel, 1997). The results can be viewed Here.