AC 2.1+3.2:Describe/ evaluate biological theories of
criminality.
Genetic Theories
XYY Theory:
- This theory suggests that crime may be attributed to chromosomal
abnormality
- XYY men are called super males- there is a suggestion that they are more
aggressive and more inclined to be violent (Jacob et al. – 1965)
- There are also studies to show that XYY men are overrepresented in the
prison population. There are 15 sufferers per 1000 in the prison population,
compared to 1 in 1000 in the general population.
- Price and Whatmore alleged that XYY males tend to be immature and
unstable with a tendency to commit motiveless property crimes.
Strengths:
- Jacob found an association between XYY syndrome and offenders imprisoned
for violent behaviour.
- Price and Whatmore found links between the syndrome and property crime
- Adler et al (2007) indicated that it is possible that aggressive and violent
behaviour is at least partly determined by genetic factors.
Limitations:
- Even if some violent offenders have the syndrome, this doesn’t prove it is the
cause of their violence.
- XYY males fit the stereotype because they are tall and well built, so are
therefore more likely to be labelled criminal by courts and police meaning
more likely to be imprisoned.
- XXY often have low intelligence meaning more likely to be caught, this
suggests that the figures in prison may be overrepresented and should not be
relied upon too heavily.
- Genetic abnormalities do not explain aggression. Theilaagrd (1984) found the
characteristics of aggression are not associated with XYY men.
Twin studies:
- These studies support the idea that an inheritable trait may cause criminal
behaviour
- Identical twins are monozygotic (MZ) as they are from one fertilised egg
meaning they share 100% of DNA, whereas dizygotic (DZ) twins only share
50% of DNA
- Johannes Lange found that MZ twins had a much higher degree of
concordance than DZ twins for criminal behaviour
criminality.
Genetic Theories
XYY Theory:
- This theory suggests that crime may be attributed to chromosomal
abnormality
- XYY men are called super males- there is a suggestion that they are more
aggressive and more inclined to be violent (Jacob et al. – 1965)
- There are also studies to show that XYY men are overrepresented in the
prison population. There are 15 sufferers per 1000 in the prison population,
compared to 1 in 1000 in the general population.
- Price and Whatmore alleged that XYY males tend to be immature and
unstable with a tendency to commit motiveless property crimes.
Strengths:
- Jacob found an association between XYY syndrome and offenders imprisoned
for violent behaviour.
- Price and Whatmore found links between the syndrome and property crime
- Adler et al (2007) indicated that it is possible that aggressive and violent
behaviour is at least partly determined by genetic factors.
Limitations:
- Even if some violent offenders have the syndrome, this doesn’t prove it is the
cause of their violence.
- XYY males fit the stereotype because they are tall and well built, so are
therefore more likely to be labelled criminal by courts and police meaning
more likely to be imprisoned.
- XXY often have low intelligence meaning more likely to be caught, this
suggests that the figures in prison may be overrepresented and should not be
relied upon too heavily.
- Genetic abnormalities do not explain aggression. Theilaagrd (1984) found the
characteristics of aggression are not associated with XYY men.
Twin studies:
- These studies support the idea that an inheritable trait may cause criminal
behaviour
- Identical twins are monozygotic (MZ) as they are from one fertilised egg
meaning they share 100% of DNA, whereas dizygotic (DZ) twins only share
50% of DNA
- Johannes Lange found that MZ twins had a much higher degree of
concordance than DZ twins for criminal behaviour
