A01.1
XYY syndrome occurs when a male has one extra chromone 23rd , so they have 47 chromones instead of 46
occurs in 1 out of 1000 male births.
not inherited but a random onccurance at conception
75% males with XYY go undetected
A03.1
strength: jacobs et al liniked XYY to criminal personalit 196mppts 3.5% of individuals in a metal health hosital in edinbruugh had - therefore relationship between mentally ill individuals higher than general population 1%
weakness: reductionist doesnt female crimes, therefore not a complete ecplnantion of how cromes occur because femalkes are criminals too and make up 5 % of prison population therefore there must be other fsctors involved in causing crime - testosterone, SLT …. bandora or dabbs?
strength- casey et al published reseach at maximum security hositals in UK - mosside and rampton
24% males tested ( over 183cm) were XYY or XYY variant
bradmoor-8%
nottingham- 8.3%
weakness: witkin et al found no direct link between crime and XYY syndrome, 4591 men in top height distribution only 12 cases XYY.
41.7% more likely to be involved in crime but not violent and only 9.3% of these were likely to be involved in violent crime
A01.2
phsycial features can be related to XYY syndrome
- tall - above average
- increased belly fat
- a large head
-unusually large teeth
- flat feet
- fifth fingers that curve inward
- scoliosis
- cystic acne during adolsesnce
IQ on average 10-15 points lower than siblings
increased risk for learning disabilities and behavioural problems
mild delays in reaching developmental milestones
learning disabilities reported 50% cases
speech delays and language problems
reading difficulties are common
dyslexia
- act to gain immediate gratification
ADHD, autism , explosive temper, impulsivity
link to crime
lower IQ leads to fustration leads to crime
bwhavioural issues- crime
impulsiviy lead to crime
A03.2
+ prince followed Jacobs work publishing a review of patients at Edinburgh hospital and studied 9 XYY individuals and the following charchteristics were noted-
above av height of others in hospital XYY 6.1” compared to XY 5.7”
and below average intelligence, mental defects
this correlates to theory
+ can allow for pre screening/ gene testing if seem to have some of common features, try and intervene with behaviour therapies/ prevention of onset of gene increase qual of life
conclusion
although thoes with XYY may be seen to have mild delays in learning development majority do not engage in criminal behaviours- no link to crime