Biological Explanations - Genetics Flashcards
Define gene
A unit of heredity which is transferred from parent to offspring and is held to determine some characteristic of the offspring.
What are the 3 studies on genetics causing criminality?
Lange (1930)
Tilhonen (2015)
Mednick (1984)
Who is Lange (1930)?
Conducted the 1st study of twins and criminal behaviour
Who did Lange study?
13 MZ twins
17 DZ twins
each twin had one twin who served time in prison
Lange findings
Both twins in
10/13 MZ twin pairs were known criminals,
2/17 DZ twins were both criminals
What are the 2 types of genes associated with criminiality?
MAOA (monoamine oxidase)
CHD13
what is MAOA associated with?
agression
what does MAOA regulate?
metabolism of serotonin in brain
What is linked to impulsive and aggressive behaviour?
low serotonin levels
what is CHD13 linked to?
ADD (attention deficit disorder)
substance abuse
What did Tiihonen (2015) do?
Tested 900 offenders in Finland
Divided into extremely violent, violent, non-violent
Tiihonen findings
found that the ‘extremely violent’ offenders had low MAOA and CHD13 activity
what did Tiihonen estimate?
5-10% of all violent crimes in Finland is due to abnormalities in one of the 2 genes
Diathesis stress of criminality
genetic predisposition + psychological trigger
e.g. having criminal role models
What did Mednick (1984) conduct?
An adoption study which compared likelihood of adoptee having criminal record
(considering if biological or adoptive parents had one)
