Answer: Model their behavior after others and have that behavior positively reinforced.
Social learning theory as initially outlined by Bandura and Walters in 1963 explains that new behaviours are acquired by means of observing and imitating others. Further explaining that a Behaviour is more likely to persist when it is being rewarded and likely to stop when it is being punished.
So is a violent person as explained in the social learning theory, the individual only became more violent because, they observed, imitated others through positive reinforcements.
