Biochemical Explanations of Crime

Males – overproduction or underproduction of hormones may cause emotional disturbances then lead to criminal behaviour.
The male hormone testosterone has been linked with crimes such as r*pe and murder.
Ellis and Coontz (1990) points out that testosterone level peak from puberty to the early 20s and this age range correlates with the highest crime rates in males.

Pre-menstrual tension (PMT), post natal depression and lactation (breastfeeding) have all been accepted as partial defences for women charged with crimes ranging from shoplifting to infanticide, on the grounds that the hormones involved have affected the defendant’s judgement, mood or self-control. 

The brain’s chemistry can be influenced by diet, for example food additives, pollution or hypoglycaemia (low blood sugar levels associated with diabetes). Some studies show that low levels of serotonin are linked with higher aggression. Serotonin regulates signals between neurons and is said to control a person’s mood.

Steroids – large amounts can make individuals extremely violent (known as ‘roid rage’). Steroids are often taken to increase muscle growth, also increase testosterone levels.

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.

Horace Williams, an American body builder, beat a man to death after taking 2,000 times the recommended dosage of steroids.

1.Sexual hormones, blood sugar levels and substance abuse can affect mood, judgment and aggression

2.Testosterone levels and male offending both peak around the same age, suggesting hormones  affect criminal behaviour

3.Alcohol produces disinhibition, reducing self-control and leading to criminal behaviour, particularly violence. Crack cocaine has been strongly linked to violent crime.

4.Bio-chemical factors are recognised by the courts. The law of infanticide states that if a mother kills her baby as a result of post-natal depression or breastfeeding, she has a partial defence to murder. Pre-menstrual tension (PMT) has been accepted as a defence in shoplifting cases.

1.Bio-chemical processes may predispose some individuals to offend, but it may require an environmental ‘trigger’ to cause actual offending.

2.Scarmella and Brown (1978) found testosterone levels do not greatly affect aggression levels in most men. 3

.Schalling (1987) found high testosterone levels in young males led to verbal aggression, but not physical violence.

4.Infanticide may be due to isolation and the responsibility for caring for a new-born child rather than  hormones.