genetic explanation +eval

candidate genes for offending

MAOA and CDH13 (not necessary to know the latter)

MAOA gene

the gene codes for an enzyme which breaks down excess serotonin and adrenaline. a lack of the MAOA gene means that there's a dysfunction of MAOA and less enzymes are created, meaning less neurotransmitters are broken down.

lack of MAOA gene and it's relation to offending

a lack of the MAOA gene means that there's a dysfunction of MAOA and less enzymes are created, meaning less neurotransmitters are broken down. therefore, messages sent through the brain are stronger and more aggressive as they aren't being inhibited

CDH13 (bonus, don't need to know but is good)

linked to problems with cognition and violent behaviour

a strength of genetic explanations of offending is that there is research evidence to support them. (twin studies)

christiansen studied 3500+ twin pairs in denmark. found concordance rates for offender behaviour was 35% for male identical twins and 13% for male non-identical twins (with slightly lower rates for females). shows that the more genetically similar you are, the higher the concordance rate for offending behaviour is. however offending behaviour cannot purely be genetic as MZ twins weren't found to have 100% concordance rate therefore environmental factors have a large influence (mention twins and identity confusion)

a strength of genetic explanations of offending is that there is research to support them. (adoption studies)

crowe found that adopted children who's biological mother had a criminal record had a 50% risk of developing a criminal record by 18 years old, while with mothers without a record children only had a 5% risk. this suggests that genetics have a large influence over offending as environmental factors have naturally been accounted for. (E.L independently)

a strength of genetic explanations of offending is that there's research evidence to support them. (family studies)

a family study which found that men who lacked the MAOA gene had a generational criminal record, however women weren't affected by it and were only carriers of the gene. this research suggests a lack of MAOA could be a reason for violent offending. it also suggests that men may be more likely to offend than women as the gene has no affect on women, therefore reflecting national statistics (men being likelier to offend)

a limitation of genetic explanations of offending is that the research evidence to support it cannot be generalised. (family studies)

the effect of the MAOA gene may not be the same for other families due to environmental factors which could have been confounding variables in that family study. therefore, due to unaccounted confounding variables, the research low internal validity, meaning it cannot be generalised to a wider population. (think individual diff, population validity.)