Is aggressive behaviour something that is learned, or do its origins lie elsewhere?
There are many psychological explanations for aggression occurring, these are, bio-social models, reinforcement and social learning. Aggression takes many forms of behaviour including verbal, physical and facial expressions, all of which, are viewed differently across cultures. Baron (1977) believes ‘Aggression is any form of behaviour directed toward the goal of harming or injuring another living being’.

Bio – social models of aggression include the frustration aggression hypothesis which states that aggression is caused by frustration, this comes about through not gaining a desired goal. (Miller 1941). For example, an individual who is recovering from some type of addiction like tobacco products, often feel agitated and may exhibit behaviours such as short tempers and impatience while the body goes through withdrawal. Bandura (1973) criticised this hypothesis and believed that aggression could occur in the absence of frustration. The Excitation transfer model which is supported by Zillmann (1979)   argues that residual arousal from an unrelated event can feed readiness to aggress in a new situation. The outcome of behaviour depends on residual non-specific arousal labelled from cues in the environment.
Aggressive behaviour causes can also stem from the presence of some type of disease or brain disorder. People with autism or some form of mental retardation may exhibit aggression in spurts, while appearing docile in between explosions of anger. In like manner, people suffering with epilepsy are also more likely to become aggressive. When the individual suffers with Attention Deficit Disorder (ADD), the aggression may develop out of sheer frustration, especially if the ADD has not been diagnosed and the individual has no idea why these sudden moods of aggressive conduct occur. Injuries to the brain can also lead to the development of aggression. In humans, the brain has...