BIOLOGICAL EXPLANATION: GENETIC EXPLANATION Flashcards
what is the genetic explanation to offending?
suggests offenders inherit a gene, or combination of genes that predispose them to commit crime
how are twin studies used to identifying offending behaviour?
twin studies are a well known method for identifying the genetic basis of behaviour
how can we identify a possible genetic tendency by looking at twin studies?
by examining MZ and DZ twins and looking at their concordance rate, we can identify a possible genetic tendency.
what was LANGE (1930) study into twins and offending behaviour?
he investigated 13 MZ and 17 DZ twins where one of the twins in each pair had spent time in prison. he found 10 of the MZ and and only 2 of the DZ twins had a co-twin who spent time in prison. this suggests genetic factors do play a role in offending behaviour
how can we use adoption studies to look at offending behaviour?
using adoption studies enables us to look at whether the offending is due to the genes inherited from their biological parents or due to the environment provided by their adoptive parents.
what was MEDNICK ET AL (1984) adoption study?
looked at over 14,000 adopted offenders in Denmark. found 13.5% criminal convictions in adoptive children with no biological or adoptive criminal parents. this rose to 20% with one criminal biological parent. the fact that this is higher for individuals with biological parents suggests that genes do play a role (as its not 100% we know that genes aren’t the only factor)
what are the 2 candidate genes linked to offending behaviour?
MAOA and CD13
what is the candidate gene MAOA linked to?
it is linked with impulsive and aggressive behaviour
what is the candidate gene CD13 linked to?
it is linked with ADHD and various other comorbid conditions inc. depression and substance abuse
what is the diathesis stress model?
a biological predisposition towards something triggered by a stressor. this is a more useful way of explaining criminal behaviour
AO3: how is ‘results suggest as link’ a limitation to the genetic explanation to offending?
this suggests that offending runs in families, not that it is due to genetic transmition. it could be social learning or environmental influences (differential association)
AO3: how is ‘criticisms of twin studies’ a limitation to the genetic explanation of offending?
evidence suggests concordance rates is higher in MZ twins. however MZ twins are likely to be treated similar by societies which could be an alternate explanation for the difference in concordance rate. concordance rates are also not 100% even With MZ twins.
AO3: how is ‘support for the diathesis stress model’ a strength to the genetic explanation of offending?
MEDNICKS 1984 study
looked at over 14,000 adopted offenders in Denmark. found 13.5% criminal convictions in adoptive children with no biological or adoptive criminal parents. this rose to 20% with one criminal biological parent. the fact that this is higher for individuals with biological parents suggests that genetic inheritance does play a role but environmental influence is also important
