Biological explantion-Genetic & Neural explanation

• What is the basic genetic explanation ?

  offenders inherit a gene or combination of genes that predispose them to commit crime
• What are the 4 factors in supoorting the genetic explanation

  -twin studies

  -adoption studies

  -candinate genes

  -diathesis stress model
• What does twin studies say for offending?

  Who conducted the study?

  -Lange

  -investigated 13 identical and non-identical twins where 1 twin has served time in prison

  he found 10 of the MZ but 2 of the dz twins had co-twins who were also in prison

  -concluded that genetic factors play a predominant role in offending behaviour
• What did the adoption studies say for offending?

  Who conducted the study?

  -Crowe

  -found adopted children who has a biological parent with a criminal record had a 50% risk of having a criminal record by the age of 18

  -whereas adopted children whose mother didn't have a criminal record only had 5% risk
• What did the candiante genes suggest about offending?

  Who conducted the study?

  -tihonen

  -genetic analysis of almost 900 offenders

  -found 2 abnormalities on 2 genes that may be associated with violent crime

  -MAOA- controls dopamine and serotonin- has been linked with aggressive behaviour

  -CDH13-links with substance abuse and ADHD

  -people with the high-risk combination are 13 times more likely to offend
• What does the diathesis stress model say for offending?

  -a tendency towards criminal behaviour may come about through the combination of genetic predisposition and biological or physiological trigger

  -for example being raised in a dysfunctional environment or criminal role model
• E-Strength-importance of genes is illustrated by twin studies


  -the importance of genes is illustrated by twin studies

  -lange who investigated mz twins and dz twins where one of each pair had served time in prision. Found that 10 of mz and 2 of dz twins had a cotwin who was also in prision

  -suggest that offending behaviour has a geentic component as mz twins share 100% of their dna and had higher concordance rate

  -increasing validity
• E-Limitation-problem using family studies is difficultiy separating nature from nurture


  -The problem with using family studies is the difficulty separating nature from nurture

  -Katz argues that family members tend to share the same environment and third variable factors such as mental illness, social deprivation and poverty

  -influence of nature and nurture cannot be separated in family studies, therefore dont offer a clear explanation

  -weaking credibility of genetic explanation
• E-Strength-Supporting evidence from adoption studies

  -supporting evidence from adoption studies

  -Crowe study

  -Suggest that inherited genes are a marginally more significant factor

  -increases its validity as adoption studies can seperate the influence of nature and nurture

  -increases credibility
• E-Llimitation-Biological determinism


  -biological determinism

  -idea of criminal gene presents ethical dilemma's as the legal system is based on criminal havibng moral responsibility

  -raise ethical question about what society does with people suspected of carrying criminal gene

  -negative implications for sentencing such as incarcentrating people with criminal gene before they even commit a crime

  -must use a careful approach
• What is the basic neural explanation for offending?

  evidence suggest that there may be neural differences in the brains of criminals and non criminals
• Most of evidence that has been investigated is on?

  antisocial persoanlity disorder

  -psychopaths
• What is APD associated with?

  reduced emontional repsonse, lack of empthay for feelings of others
• What are the 2 sub explantions for the neural explanation?

  -prefrontal cortex

  -mirror neurons
• What does the prefrontal cortex suggest about offending?

  Who conducted it?

  -rainee

  -reported there are several dozen studies of brain imaging that people with APD have reduced activity in the prefrontal cortex (the part that regulates emotional behaviour)

  -also found 11% reduction in the volume of grey matter in the prefrontal cortex compared to control group
• What do mirror neurons suggest about offending?

  Who conducted it?

  -Keysers found that only when criminals were asked to emphasise (with a person depicted on film experiencing pain) did their empathy reaction (controlled by mirror neurons in the brain)

  -suggest that APD are not totally without empathy but may have a neural "switch" that can be turned on and off, unlike normal brain where empathy switch is permanently on
• E-Limitation-whether neural abnormalities are the cause or effect of offending behaviour


  -whether neural abnormalities are the cause or effect of offending behvaiour

  -research only highlights a correlation between head injuries and later criminality

  -it is possible that it is a unauthentic relationship

  -for example someone who grew up in a violent household or engages in risky business might be more likely to suffer a head injury

  -no cause and effect

  -reduces credibility
• E-Strength-Lead to possible methods of treatment

  -lead to possible methods of treatment

  -for exmaple of low levels of serotonin cause increased aggressiveness in criminals, then people in prision could be given diets or medications that would enhance their seritonin levels and hopefully reduce thier aggression

  -easier emthods compared to psychological therpaies

  -increases ecological validity
• E-Limitation-research is related to aggresion rather than offending


  -research is realted to aggression rather than offending

  -research on nt often relied on studies of non human animals

  -undermines the potential relevance of such information for understanding human offending behaviour

  -reduce validity
• E-Limitation-Biological reductionism


  -Biological reductionism

  -reducing criminal behaviour to a neural level may be inappropriate and overly simplistic

  -there are several factors that lead to offending behaviour such as personality types and cognitive distortions

  -should take a holistic approach to get a comprehensive reason why we should offend

  -limited and should not be used on its own