Tuesday, 12 May 2015

TURNING TO CRIME: Biology - How does our biology influence criminal behaviour?


Dabbs: To investigate the link between testosterone and crime

Sample: 692 adult male prisoners.Two groups were created - prisoners who had committed violent crimes and criminals who had committed non-violent crimes.

Method: Measured testosterone levels in their saliva.

The researchers found that inmates who committed crimes of sex and violence had higher testosterone levels than inmates that were jailed for property crimes or drug abuse. In addition, they say, "inmates with higher testosterone levels... violated more rules in prison, especially rules involving open confrontation."

Dabbs et al. say that "the variety of rule violations suggests the behavior of high testosterone reflects a lack of control over emotions, as well as aggression and violence. The higher testosterone suggests that males are more likely to commit crimes more than females due to that fact that they have higher levels of testosterone.


Raine: Understanding the development of anti-social and aggressive children with a biological focus:

Methodology: A review article - this involves summarising a large amount of studies and collating the findings by describing what the majority of research is saying.

Procedure: Raine reviewed and summarised findings from a selection of articles that focused on the links between brain-imaging results and anti-social behaviour through a child's development.

Results: Raine draws together many different studies that look at the biological influences that contribute to aggression and anti-social behaviour. Research suggests that the adolescent brain is still forming its final connections in the pre-frontal lobes right up to the age of 20. Activity in the pre-frontal lobes has been shown to be lower in individuals who are likely to be aggressive and anti-social. This may explain why offending peaks during adolescence. In addition, birth complications, physical abuse, malnutrition, smoking and drinking during pregnancy all add to the risk. This is because these types of behaviour during pregnancy, restrict the development of the baby and therefore restrict the growth of the babies brain - leading to lower activity in the pre-frontal lobes.

Conclusions: Early intervention and prevention may be an effective way of reversing biological deficits in the brain that predispose anti-social and aggressive behaviour.


Brunner: A study of violence in a family with a genetic abnormality

One biological explanation of crime is that some people may be predisposed to crime as they differ in terms of genes and serotonin levels. Low levels of serotonin have been associated with mood disorders and aggressive impulsive acts, as serotonin is involved in brain development. Serotonin is also known as the 'feel good' chemical. Serotonin is the chemical released during sexual intercourse. In addition, some psychologists have claimed that inheriting certain genes may predispose someone to crime.

Aim: To find a biological explanation of a Dutch family where all the 5 males were affected by borderline mental retardation and abnormal violent behaviour. The males exhibited criminal behaviours such as arson, rape and exhibitionism.

Method: Numerous urine samples were taken and analysed from the sample over a period of 24 hours.

Results and conclusions: A mutation in the X chromosome was identified, which explained why no females were affected as the XX genetic make-up counteracted the mutation. Brunner also found disturbed monoamine metabolism associated with a deficit of MAOA. MAOA is involved in serotonin metabolism, and thus Brunner concluded that the impairment of this gene was the cause of the disturbed metabolism which then lead to mental retardation as well as their aggressive behaviour. However, it is important to point out that not all males in the family were affected by violent behaviour, even when they suffered with mental retardation. In addition, this is an extremely rare condition and even if it were responsible for the criminal behaviour, it would be very difficult to generalise the findings.



  1. In the approaches and research methods paper, if the physiological approach comes up can we use Brunner as one of the pieces of research? Also can be use Johansson and Geer and Maisel?

  2. I'm so sorry! I didn't even see this! Bit too late now. But you got an amazing grade! x