XYY

Question 1

A01.1

Answer 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 100 male births.
not inherited but a random onccurance at conception
75% males with XYY go undetected

Question 2

A03.1

Answer 2

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

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. only 9.3% of these were likely to be involved in violent crime

Question 3

A01.2

Answer 3

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
ADHD, autism , explosive temper, impulsivity
link to crime

lower IQ leads to fustration leads to crime

bwhavioural issues- crime
impulsiviy lead to crime