jacobs XYY

Question 1

strength: men in prisons

Answer 1

One study by Jacob et al (1965) found that a significant number of men in prison had XYY sex chromosomes, instead of the normal XY.

Question 2

strength: Alder et al

Answer 2

Alder et al (2007) indicated that it is possible that aggressive and violent behaviour is at least partly determined by genetic factors.

Question 3

strength: Price & Whatmore

Answer 3

Price and Whatmore (1967) found some links between the syndrome and property crime.

Question 4

weakness: over-represented

Answer 4

XYY males are tall and well built, so they fit the stereotypes of ‘violent offenders’ and get labelled as such by the courts, so they are more likely to get a prison sentence. As a result, the XYY males are over – represented in samples drawn from prisoners and this overstates the importance of the syndrome as a possible cause of crime.

Question 5

weakness: low intelligence

Answer 5

Alternatively, XYY males may be overrepresented in prison because they often have low intelligence, meaning they are more likely to be caught.

Question 6

weakness: rare

Answer 6

The syndrome is very rare (1 in 1000 men) so it cannot explain much crime.