Aggression

A general term for a wide variety of acts of hostility. A number of factors, including human evolutionary survival strategies, are thought to be involved in aggression. Androgen hormones, the male sex hormones, seem to promote aggression, whereas oestrogen hormones, the female sex hormones, actively suppress it. Age is another factor; aggression is more common among teenagers and young adults. Sometimes, a brain tumour or head injury leads to aggressive behaviour. Psychiatric conditions associated with aggressive outbursts are schizophrenia, antisocial personality disorder, mania, and abuse of amfetamines or alcohol. Temporal lobe epilepsy, hypoglycaemia, and confusion due to physical illnesses are other, less common, medical causes.