The brain's chemistry can be influenced by diet, for example food additives, pollution or hypoglycaemia (low blood sugar levels associated with forms of diabetes)
Low levels of serotonin
Linked with higher aggression
Serotonin
Regulates signals between neurons and is said to control a person's mood
Scerbo and Raine (1993) conducted a meta-analysis on 29 studies into anti-social adults and children, finding low levels of serotonin in all of them
Control of serotonin levels by diet
Some foods, including dark chocolate, cheese, nuts, salmon, turkey and chicken, can help raise serotonin levels
People who take large amounts of steroids
Can become extremely violent (known as 'roid rage')
Steroids, often taken to increase muscle growth, also increase testosterone levels
