View mindmap
  • Biological Theories
    • Sheldon
      • Came up with the idea that criminals are more likely to have mesomorphic bodies (hard and muscular) than any other type of body (thin, soft, round etc)
    • XXY theory
      • The theory that an extra Y chromosome can explain criminal behaviour
        • Jacob et al and Casey et al's studies found that XXY men are overrepresented in prisons. Adler et al suggests a link between aggressive/ violent behaviour and genetic factors
        • Studies have found that genetic abnormalities are common in the pop. so cannot be used to explain aggression. Reductionist. Theilgaard found no association between XXY men and aggression
      • Theilgaard took blood samples from 30,000 men and conducted personality tests to see whether XXY men were more aggressive.
        • He found that although they had lower levels of intelligence, there was no evidence of a criminal gene
    • Adoption studies
      • If the child is more like their adopted environment then nurture is the cause for their criminal behaviour
        • Info about bio family is not always available. Age affects whether the child is influenced by bio or adoptive parents. Often children are placed with adoptive families similar to bio families.
      • If the child is more like their bio parents then genetics are the cause of their criminal behaviour. (nature)
        • Easier to separate genetic and environmental factors. Studies show there is a link between adoptive children and their bio parents. Mednick et al's study shows this.
      • Hitchings and Mednick (1975) studied 14,000 adopted children and found that a high proportion of boys that had criminal convictions had biological parents who also had criminal convictions.
        • This suggests a link between aggression and genes.
    • Lombroso
      • Believed that criminals could be identified by their physical defects that make them look savage  e.g a twisted nose
    • Physiological
    • Genetic
    • Twin studies
      • Support the idea that criminal behaviour can be caused by heritable traits
        • Early studies e.g Lange were inadequately controlled and lacked validity. The small samples cannot be generalised to the whole pop. If twins are brought up in the same environment then nurture can be an equal factor
        • Natural experiments - relationship between twins is naturally occurring. Christianson supports the idea of genetics explaining criminality, Twin studies have helped the prevention of vulnerable disorders
      • Monozygotic (MZ) twins share 100% DNA (share a placenta) whereas Dizygotic twins (DZ) share 50% DNA (separate placentas)
    • Richard Speck
      • American mass murderer who tortured and ***** nurses in a Chicago hospital so who was thought to have had XYY syndrome but had XY chromosomes instead


No comments have yet been made

Similar Criminology resources:

See all Criminology resources »See all Biological factors resources »