XYY

Cards (8)

What is the XYY theory? 
- Suggests that some crime might be attributable to a chromosome abnormality
- Contains an extra Y chromosome
- More aggressive and more inclined to be violent
- Jacob Et al men with the XYY were more aggressive than normal XY men
- Some studies show that XYY men are over represented in the prison population. 15 sufferers of 1000 in prisons 1 per 1000 in general population
- John Wayne Gracy had XYY and killed 33 men
Strength - Price and Whatmore (1967) found a link between XYY syndrome and...
...property crime
Strength - Alder et al. (2007) argues that aggressive and violent behavior is... 
...at least partly determined by genetic factors
Limit - Focusing too much on genetics...
...ignores other causes of crime e.g. poverty
Limit - The syndrome is very rare (1 in 1000)... 
...so it does not explain much crime
Limit - Even if violent offenders have the syndrome, this does not prove... 
...that this is the cause of their violent and aggressive behavior
Limit - Theilgaard (1984) examines the traits of XYY men compared to XY men... 
...and found no difference at all in terms of aggression
Limit - Only explains aggressive and violent acts committed by males... 
...therefore does not explain any other type of crime