At the core of most acts of violence, whether unprovoked or in retaliation to a perceived slight, is the emotion of aggression. In psychology, aggression is described as behaviour that can cause physical or psychological harm to the self, others or the environment. Unlike assertiveness, the verbal expression of thoughts and feelings while respecting others’ viewpoints and boundaries, aggression is invasive, forceful, attacking behaviour. Gross defines aggression as: ‘The intentional infliction of some form of harm on others’.
Evolutionary theory suggests that aggression is biological; it’s imprinted in our genes, and maintained over aeons as the human species has adapted to changing social and environmental demands. Darwin’s concept of sexual selection holds that the fittest and most aggressive males are the most successful in finding a mate. Others (Lorenz, 1966) argue that aggression is a necessary survival instinct. Areas of high population density lead to competition for scarce resources, e.g. jobs, housing, causing aggression among individuals and groups.
Medical studies have shown that certain disorders such a brain tumours and the consumption of prescription and illegal drugs can produce uncharacteristically aggressive behaviour and mood swings in people. Alcohol, caffeine and hormones such as testosterone have all been linked to aggressive behaviour, with the popularity of energy drinks containing high levels of caffeine and other stimulants being blamed for lowered concentration levels and risky or aggressive behaviour among young people.
Relational aggression occurs in bullying and involves physically or psychologically violent re-occurring and unprovoked acts, where the bully and victim have unequal physical strength and/or psychological power (D. Olweus 1999) . Three forms of relational aggression have been observed (L. Steinberg, 2008):
- exclusion from social activities
- starting rumours and spreading gossip
- the withdrawal of friendship and attention
More subtle is passive aggressive behavior, where instead of stating honest feelings of annoyance, upset or disappointment, the person closes up. They may change their behaviour, act sulkily and exude anger. Hostility may be disguised as jokes, by procrastination, sullen and resentful behaviour – or the constant failure to carry out tasks they are responsible for.