ABSTRACT
Aggression is a social behaviour expressed during conflict as a means to obtain or defend resources. Virtually all species display some form of aggression, from fruit flies and rodents to humans. When it is expressed in context, aggression is a functional and adaptive behaviour. Protecting and defending oneself, offspring, and resources is crucial to survival and maintenance of any individual’s fitness. In contrast, aggression that is exaggerated or persists out of context may be considered pathological. This latter form of aggression represents a tremendous burden to human society. In 2014, over a million violent crimes were reported in each the United States and England (United States Department of Justice, 2015; United Kingdom Office for National Statistics, 2016), costing billions in government spending (McCollister, French & Fang, 2010). There is an urgent need to understand why some individuals display inappropriate aggression and how to prevent it.
