Criminal Behaviours - Biological Explanations: Inherited Criminality

Question 1

When describing this explanation, what are the 5 components to describe

Answer 1

• genetic factors
• searching for candidate genes
• diathesis-stress
• differences in brain
• inherited personality

Question 2

Describe genetic factors

Answer 2

• Your genes predispose you to behaviour
• Evidence for this comes from Twin Studies. MZ twins = identical and share 100% of
  DNA. DZ twins = non identical and share 50% of DNA
• If criminality was inherited, then we would expect a higher concordance rate in MZ then DZ twins
• Adrian Raine (1993) reviewed lots of research on delinquent behaviour in twins and found there 52% concordance in MZ twins, and 21% concordance in DZ twins. This suggests that criminality has a genetic component which is inherited.

Question 3

Describe searching for candidate genes

Answer 3

• researchers have mapped 2 genes responsible for criminal behaviour, These are:
  1) MAOA (monoamine oxidase A) or sometimes called ‘warrior gene’
  2) CDH13 (Cadherin 13)
  -Han Brunner et al (1993). analysed the genes of 28 male members of a Dutch family with a history of criminality, and found that they all shared a gene that led to this criminal behaviour, as it led to low levels of MAOA (an enzyme which breaks down dopamine in the synapse). This led to them all having high levels of dopamine as a result of a lack of the MAOA enzyme, which then led to criminal behaviour.
• Jari Tihonen et al (2015) looked at 900 offenders, finding evidence of low MAOA as well as low activity of the CDH13 gene. This led to the estimation that 5-10% of all violent crime in Finland was down to abnormalities with these particular genes.

Question 4

Describe diathesis stress

Answer 4

-Diathesis: a genetic predisposition
- Stress: an environmental trigger
- Certain triggers (such as high levels of stress or maltreatment in childhood) in your environment will give you a genetic predisposition to be more vulnerable to that stress, and therefore cause criminal behaviour
- Therefore epigenetics is responsible for criminal behaviour. This is where gene expression is turned on and off in response to your environment.
- You may have the warrior gene, but without something in your environment to trigger it, you won’t express criminal behaviour.
-Avshalom Caspi et al (2002) used data from the longitudinal Dunedin study that followed about 1,000 people from when they were babies in the 1970s. He assessed antisocial behaviour at age 26 and found that 12% of those men with the low MAOA gene had experienced maltreatment in their childhood, but were also responsible for 44% of violent convictions. This suggests that biology is certainly involved in criminal behaviour.

Question 5

Describe differences in brain

Answer 5

• Criminal genes = differences in areas of the brain or differences how the brain functions
• Adrian Raine (2004) cited 71 brain imaging studies showing that murderers, psychopaths and violent individuals have reduced functioning in the prefrontal cortex (the area of the brain involved in regulating emotion and controlling behaviour, and moral behaviour in general). Lowered activity in this area is associated with impulsiveness and loss of control. Therefore suggests the brain plays a role in criminal behaviour.
• Seo et al 2008, suggest that low levels of serotonin may predispose individuals to impulsive aggression and criminal behaviour, partly because this neurotransmitter normally inhibits the prefrontal cortex. Low levels of serotonin are linked to criminality (as well as depression). Dopamine hyperactivity may enhance this effect
• Both very high and very low levels of noradrenaline have been linked to aggression, violence and criminality. Wright et al (2015) found that Noradrenaline helps people react to perceived threats appropriately, as it works as a part of your anxiety system. Therefore having too low levels = you don’t perceive the police as a threat = you commit
  crime

Question 6

Describe inherited personality

Answer 6

Eysenck’s theory of criminal personality says that some people inherit types of behaviour that predispose them to behaving in a criminal way

Question 7

When evaluating this explanation, what do you talk about?

Answer 7

:)
- twin studies supporting research
- scientific
:(
- no causal relationship (nurture rather than nature)
- issues with deterministic stance