genetic offending explanation

Question 1

how are genetic factors studied in psychology

Answer 1

family studies, adoption studies, and twin studies

Question 2

what was Lange’s research

Answer 2

looked at 13 MZ twins and 17 DZ twins where one of the twins in each pair had time in prison

Question 3

what were Lange’s findings

Answer 3

10 of the MZ twins but only 2 of the DZ twins had a co-twin also in prison, supporting the view that offending may have a genetic component due to genetically identical/non/genetically identical

Question 4

what was Christiansen’s study

Answer 4

studied 3500 twin pairs born 1890-1910, checking their offender behaviour against police records

Question 5

what’re the results of Christiansen’s study

Answer 5

he found a concordance faye for offending of 35% for MZ twins and 13% for DZ twins, supporting the view that offending may have a genetic component

Question 6

what did Crowe find

Answer 6

children whose biological mother has a criminal record had a 50% risk of having a criminal record by 18, whereas adopted children whose bio mother didn’t have a criminal record only had a 5% risk, indicating strong genetic component in offending behaviour

Question 7

what’re candidate genes

Answer 7

isolated genes believed to play a role in behaviour

Question 8

what’re 2 abnormal offender genes found by Tiihonen

Answer 8

MAOA gene

CDH13 gene

Question 9

what is the MAOA gene

Answer 9

aka ‘warrior gene’: chemical that helps break down excess neurotransmitters (serotonin & dopamine) in the synapse before reuptake process. If defective, there’ll be a lack of MAOA, serotonin will build up, making someone respond to stress with aggression and take risk-taking behaviours

Question 10

what is the CDH13

Answer 10

linked to attention deficit disorder and substance abuse

Question 11

what’re Tiihonen’s findings

Answer 11

5-10% of all severe Finnish violent crimes are attributed to MAOA/CDH13. thus high risk combination makes people 13x more likely to have a history of violent behaviour

Question 12

what is the diathesis-stress model

Answer 12

suggests offending behaviour to be due to a combination of:
•genetic predisposition (diathesis)
•biological/psychological stressor or ‘trigger’ (dysfunction raised environment)

Question 13

what’re 2 negative evaluations for genetic explanations

Answer 13

treatment of MZ twins (nature nurture)
adoption study issues

Question 14

how is nature vs nurture an issue for genetic explanations/all twin studies

Answer 14

MZ and DZ twins experience similar environments, with MZ twins particularly being treated more similarly due to them being identical, affecting their behaviour. this means results may have higher MZ concordance rates due to being treated more similarly than DZ’s, weakening conclusion validity

Question 15

how are adoption study issues a negative evaluation for genetic explanations/all adoption studies

Answer 15

some children are adopted late, meaning they have a considerable time with biological parents, with many children keeping form of some sort with their biological parents. the methodological issue leads to nature and nurture being impossible to fully separate due to the biological parent environmental issues

Question 16

what is a positive support of genetic explanations for offending

Answer 16

Mednick researched 13,000 danish petty offence adoptees. if neither bio/adopt patent had a record then 13.5% chance of adoptees offending, bio parent with a record 20%, with BOTH parent figure rose to 24.5%. suggests an importance of genetic inheritance role for offending, but environmental influences cannot be disregarded