Evaluation of XYY Syndrome and Crime Flashcards
Jacobs et al. (1965)
Jacobs et al. (1965) found 15 sufferers in 10,000 in the prison population compared to 1 in 10,000 in the normal population
Arthur Shawcross
A serial killer found to have XYY syndrome who killed most of his 11 victims after being paroled for the manslaughter of two children
+ Birken et al.
Birken et al. (2006) found a high frequency of XYY males in sexual homocide - suggests correlation between XYY and sexual crime, validating the theory that XYY influence criminality
+ Practical application
Results from studies can be used to prevent potential criminality from XYY males in the future, for example by offering therapies and treatments to those with the condition deemed a threat - suggests research into XYY has practical application for preventing crime, thus keeping society safe
- Re and Birkhoff
A meta-analysis by Re and Birkhoff (2015) considered 50 years of evidence and concluded that there is no link between XYY and offending behaviour - findings that suggest link between XYY and crime lack reliability, undermining the theory
- Only males
XYY only affects biological males - all research into XYY is androcentric and cannot explain criminality in females
- Sample bias
Studies of XYY men and criminal tendencies aim at examining violent and aggressive behaviour in XYY males, and most start their research in prisons and mental institutions, places where they are bound to find such behaviours, whether exhibited by XYY males or XY males - the samples being studies are biased, reducing the validity of studies into XYY
- Look different (environment)
Those with XYY syndrome tend to look different, so may be treated differently, often negatively, by society - suggests crime is not limited to the syndrome but rather to the environmental impact of it. Self-fulfilling prophecy may be a better explanation of crime
