XYY

Question 1

What is XYY syndrome?

Answer 1

A chromosome abnormality in males - random occurrence (not inherited)

Question 2

Example?

Answer 2

John Wayne Gacy - killed at least 33 men and young boys and had XYY

Question 3

How many males have it in general population?

Answer 3

1 in 1000

Question 4

How many males experience a speech delay with XYY?

Answer 4

50%

Question 5

5 other symptoms:

Answer 5

• grow faster and taller than usual
• normal IQ but around 10-15 points lower than sibling
• get easily distracted
• more impulsive and physically active
• more physically aggressive and lack empathy

Question 6

What did Stockholm do and find?

Answer 6

• studied 161 males with XYY
• found they had committed more crimes compared to XY males, except from drug and traffic related crimes
• HOWEVER, when controlling factors such as education, fatherhood and relationships, differences were only small
• concluded there was an increased risk of offending by XYY males

Question 7

Strengths:

Answer 7

• Useful - with the knowledge of XYY males being less able to concentrate and more aggressive, things can be put in place such as anger management and learning support - can help to reduce antisocial behaviours
• Jacobs - found an overrepresentation of XYY males in prison - 15 in 1000 - suggested XYY was responsible for criminal behaviour

Question 8

Weaknesses:

Answer 8

• Usefulness - doesn’t explain why there are violent female offenders - must be other reasons which can explain why violent crimes are committed as females don’t have extra Y chromosome
• Reductionist - only takes violent crimes into account rather than all criminal behaviours - doesn’t take into consideration any other causes or influences of criminal behaviour