XYY

Question 1

Strength

Answer 1

Scientific correlation with criminal
behaviour
➤ 15 in 1000 in prisons vs. 1 in 1000
in general population.

Question 2

Weakness

Answer 2

➤ Most crimes committed by
non-XYY individuals.
➤ Ignores environmental/social
factors.
➤ Only explains violent crime.

Question 3

Policy what is it?

Answer 3

Diet and brain chemicals (called neurochemicals) can
affect how people feel and behave. One important
chemical is serotonin, which helps control mood and
behaviour. If someone has low serotonin, they might
get angry or act without thinking. By eating a
healthier diet, people can boost their serotonin levels
and become calmer and less aggressive.

Question 4

Is it effective

Answer 4

Studies by Virkkunen and Schöenthaler found that
when people changed their diet—like eating less
sugar and more vitamins—their behaviour improved,
and they became less aggressive. So, a better diet
can help reduce bad behaviour and possibly crime.

Question 5

What theory is this influenced by?

Answer 5

This idea links to biological theories of crime, like
the XYY theory, which says some people may be
born more likely to be aggressive. While we can’t
change their genes, we can help reduce bad
behaviour through diet, which helps manage how
their brain works

Question 6

Core

Answer 6

• Sometimes there can be
  a problem with sperm production which can
  result in a male ending up with an extra Y
  chromosome. Characteristics include - Taller
  height, slightly larger head size and widely
  spaced eyes

Question 7

Expanded

Answer 7

Price Et al - The
Supermale - display higher levels of aggression,
high prison population - commit extreme
offences

Question 8

Study

Answer 8

Jacob et al- men with XYY were more aggressive,

disproportionately represented in prison population.
They found 15 men with XYY per 1000 in prisons
compared to only 1 XYY case per 1000 men in the
general population