Biochemical

• Overproduction or underproduction of hormones may cause emotional disturbances that lead to criminal behaviour. The male sex hormone, testosterone, has been linked to murder and rape.
• Ellis and Coontz: testosterone levels peak from puberty to early 20s, 30s - this age correlates with the highest crime rates of males.
• Premenstrual tension, postnatal depression and lactation have all been accepted as partial defences or women charged with crimes.
• Steve Jones: Testosterone is especially dangerous in drug form or as steroids. Men are murdered more than women, and by predominantly men.
• Low blood sugar (hypoglycaemia) can trigger aggressive reactions. It has been correlated to alcohol abuse, which is also linked to criminal behaviour. Schoenthaler claims that by reducing the daily sucrose intake of young offenders, antisocial behaviour could be reduced.
• Substance abuse has also been linked to criminality. Legal substances, such as alcohol and glues, medically prescribed drugs (such as barbiturates) and illegal substances (such as cannabis and cocaine) are all associated with violent crime. Saunders calculated that alcohol played a significant role in about 1000 arrests per day.
• In the USA, Flanzer estimated that 80% of family violence cases involved alcohol.
• Food additives and diet, allergens, vitamin deficiencies and lead pollution are all contributors to criminal activity. Lead and the synthetic food colouring tartrazine, for example, has been linked with hyperactivity. Vitamin B deficiency has been linked to erratic and aggressive behaviour.
• Neurotransmitters are chemicals found in the brain that help transmit messages being synapses. One such neurotransmitter is serotonin, associated with mood regulation.
• Scerbo and Raine conducted a meta analysis on 29 studies into antisocial adults and children and found low levels of serotonin associated with all of them. The idea is that low levels of serotonin is associated with higher levels of aggression (and therefore violent crime).
• What are low levels of serotonin associated with?

  Depression - but it might be depression that causes a drop in serotonin levels.
• Tryptophan is an important amino acid responsible for the production of serotonin. Some foods that contain this are egg, cheese and poultry.
• A strength of biochemical theories would be the logical reasoning: sexual hormones, blood sugar levels and substance abuse can have effects on mood - it is why drugs and certain substances are so addictive in the first place.
• There is backing evidence from the correlation between peak testosterone levels and highest crime rates in men.
• A second strength of biochemical theories would be that alcohol produces dis-inhibition, reducing self control and leading to criminal behaviour. Crack cocaine = violence
• A strength of biochemical theories would be that they 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.
• A limitation of biochemical theories would be that they may predispose some individuals, but they may require an environmental trigger to cause actual offending.
• A limitation of biochemical theories would be that Scarmella and Brown found that testosterone levels don't greatly affect men's aggression.
• Schalling found high testosterone levels in young males led to verbal aggression, but not physical violence.
• Another biochemical limitation would be that infanticide may be due to isolation and the responsibility for caring for a newborn child rather than hormones.
• One drug treatment for biochemical disorders would be vivitrol. This is a once a month injection that blocks the receptors for opiates. It does not block alcohol receptors in the same way, but can be helpful.
• Another drug treatment would be Antabuse. It is used in aversion therapy to treat alcoholism. It works by preventing the body from breaking down alcohol, immediately causing extreme hangover symptoms if the user consumes even a small quantity.
• Another drug treatment would be methadone, which is used to treat addicts, as a long term alternative to heroin or to prevent withdrawal symptoms. By providing a legal, medically controlled substitute, it helps to reduce crime.
• Another drug treatment is stilbestrol - a form of 'chemical castration' that has been used in prison to treat male sex offenders. Stilbestrol is a female hormone, and has side effects such as feminisation, breast development and serious psychiatric disorders.
• Drugs have also been used to manage violent prisoners. Sedatives and tranquillisers such as valium, librium and largactic are all used.
• Gasch et al - supplementing prisoners with diets with vitamins, fatty acids and minerals caused a remarkable reduction in anti-social behaviour of up to 37% in cases of violent incidents.
• Vitamin B3 has been used to treat some forms of schizophrenia, a disorder sometimes associated with violent behaviour.
• Some forms of surgery have also been employed. Surgical castration has been used in the past to change offending behaviour, for example in Denmark and the USA. The results have been mixed though: men could restore their testosterone levels through injections or pills. Some 65% of castrated sex offenders reported a drop in sex drive, according to a German study conducted in the 60s, but 18% recorded being able to function regularly 20 years after the procedure.
• Castration may be effective though, as a 2005 report found that between 0 and 10% of sex offenders repeat their crimes after the procedure.
• Lobotomies have also been used. It is a major procedure that cuts the connection between the frontal lobes of the brain and the thalamus. It can have serious side effects, such as dementia, epilepsy, brain infection and intellectual impairment.