XYY syndrome Flashcards
what is XYY syndrome?
a genetic condition that concurs when a male has an extra Y chromosome within the 23rd pair of chromosomes instead of the usual XY. they thereofre have a total of 47 chromosomes.
occurs randomly at time of contraception.
what have studies shown?
- many men don’t know they have it
- most boys will have a normal development although some may grow faster and taller than siblings.
- some have shown they have lower level of intelligence
what does it make men do?
- overly aggressive and lack empathy
- it has no effect on testosterone or sexual development but they may be more impulsive
- early studies suggested they were ten times more likely to be a criminal and more aggressive than xy men. this led to the belief that they are more likely to be violent criminals.
evidence
jacobs et al conducted a chromosomes survey of male patients at a max security hospital in Scotland.
found that men with the XYY pattern were overrepresented in prison populations compared to general pop.
:( however there may be other genetic traits that are important, for example medick studied male adoptees and 85% with a criminal record or mild offence had a father with one. whereas young male adoptees without a criminal record had a father with a criminal record 31 of the time. therefore XYY is a rather limited explanation of criminality.
application
genetic screening could be used to identify
this may be useful for diagnosis and early intervention to reduce the chances of criminal behaviour in future.
CA= such practices may be regarded as a form of social control thereby raising significant ethical issues.
S/W
:( reductionist
:( the data is a correlation and therefore cause and effect can not be established. this means that it is diffcult to directly link criminality to XYY.
:) ca= that said, it can explain gender differences eg females can not be born XYY and thereof could explain prison pop.
bio explanations suggest individuals are not accountable for their behaviour - dangerous message and socially sensitive.
alternative
social learning theory
conc- while XYY may explain criminal behaviour, it is reductionist because it cannot explain crimes committed by females.