AC 2.1 Biological Causes of Criminality

• Lombroso - Outline

  • Father of modern criminology, criminal profiling.
  • Atavistic features: strong jaw, high cheekbones, flattened or upturned nose, sloping brow, long arms, large ears, extra toes/nipples/fingers.
  • People are born criminal, can identify by features, separate species, primitive sub species "genetic throwbacks".
• Lombroso - Research

  • Lombroso examined 383 dead criminals and 3839 living (all Italian men) - 40% had atavistic features.
  • University in China entered 1856 men (½ criminal ½ not) into AI system. 6% innocent identified at criminal, and 83% criminal identified as criminal.
• Lombroso - Strengths

  • This theory could help identify criminals, led to development of offender profiling.
  • Evidence to support - Lombroso 40%, University in China 83%.
  • Goring found criminals had lower levels of intelligence.
• Lombroso - Weaknesses

  • Unrepresentative of the whole world as he only researched Italian men.
  • Criticised for being racist - features more commonly found in some ethnic minorities.
  • Not everyone with atavistic markers is criminal and vice versa.
  • Could also contribute to wrongful targeting, stereotyping, and self-fulfilling prophecy.
• Sheldon - Outline

  • Somatotypes - ectomorphic (thin, tall, introverted), endomorphic (fat, soft, sociable), and mesomorphic (muscular, hard, aggressive).
  • Correlation between body types/shapes and criminal activity.
• Sheldon - Research

  • Sheldon analysed 4000 bodies and found the three somatotypes. Mesomorphic most likely to commit crime.
  • Glueck and Glueck - 60% of delinquents mesomorphic, 31% on non-delinquents mesomorphic.
  • College study with 200 participants both deviant and not. Rated on a scale of 1-7, criminals average 4.6, students average 3.8.
• Sheldon - Strengths

  • Starting point for criminal profiling.
  • Putwain 2002 found association between body shapes and criminality.
  • Glueck and Glueck - 60% delinquents mesomorphic.
• Sheldon - Weaknesses

  • Could lead to stereotyping by police and self-fulfilling prophecy.
  • Doesn't take into account that body shapes can change.
  • With the rating scale, ratings of mesomorphic are subjective to each person.
  • Not all criminals are mesomorphic and vice versa.
• Neural (PFC) - Outline

  • Pre-frontal cortex responsible for decision making, logic, and impulse control.
  • Impulsive behaviour leads to making irrational decisions and lack of logical thinking.
  • Damaging certain parts of brain can cause personality changes - making a criminal.
• Neural (PFC)- Research

  • Phineas Gage - rod through brain, didn't die but suffered huge personality changes.
  • Raine (1994) used PET scans to study brains of murders - had less brain activity.
  • Charles Whitman - experiences huge personality changes, became more aggressive, ended up committing schools shooting then suicide. Autopsy found tumour near PFC, affecting logic and impulse control.
• Neural (PFC) - Strengths/Weaknesses

  • Proves that damage to brain can cause personality changes - making a person more aggressive or have impulsive thoughts.
• Neurotransmitter (Serotonin) - Outline

  • Serotonin travels between neurons and influences emotions and mood stability.
  • Low levels have been linked to higher levels of aggression.
• Neurotransmitters (Serotonin) - Research

  • Excessive exposure in womb can lead to desensitisation.
• Neurotransmitters (Serotonin) - Strengths

  • People with low levels more likely to commit violent crimes.
• Neurotransmitters (Serotonin) - Weaknesses

  • Desensitisation can occur from excessive exposure - cannot feel effect of serotonin.
• Jacobs XYY- Outline

  • Chromosome abnormality - structures in cell nucleus that contains genes. 46 chromosomes 44 for physical form and 2 determine sex.
  • Presence of extra Y chromosome creates criminality - higher levels of testosterone cause aggression and violence.
  • Very tall, well-built, and low intelligence - lack of understanding of consequences, and more physically able.
• Jacobs XYY - Research

  • Studies imprisoned criminals - such as those in psychiatric hospitals, higher proportion of inmates tended to have XYY.
  • 15/1000 in prison likely to have condition. 1/1000 in general public.
  • Men with XYY more likely to be stereotyped as criminal.
• Jacobs XYY - Strengths

  • Consistent with Sheldon's theory - mesomorphs and criminality.
  • Jacobs found association between XYY and aggression.
  • Price and Whatmore found links between XYY and property crime.
• Jacobs XYY - Weaknesses

  • Cannot explain all criminality - it is a rare condition.
  • Ignores female criminality (20% of criminals are female).
  • Only suggests correlation - cannot establish that XYY causes violence/crime.
• Candidate Genes - Outline

  • MAOA acts as neurotransmitter, controls serotonin. Increased levels of aggression and violence. Linked aggression when environmental factors (abuse) occur during development.
  • CDH-13 effects on mobilisation. Linked to ADHD, schizophrenia, bipolar, and substance abuse. Plays role in controlling violent and impulsive behaviour.
• Candidate Genes - Research

  • Bruner analysed DNA of 28 male members of a Dutch family with history of impulsive and violent behaviour
  • Found they shared particular gene that lead to low levels of MAOA
• Candidate Genes - Strengths/Weaknesses

  • Bruner's research proves these genes can be passed down through generations
• Twin Studies - Outline

  • Concordance rate - rate of probability that two people with shared genes will both develop offending/criminal behaviour
  • Monozygotic share 100% DNA, dizygotic share 50% DNA
  • Identical twins both inherit candidate gene
• Twin Studies - Research

  • Lange found 10/13 MZ in prison had other twin also in prison, 2/17 DZ in prison also had other twin in prison
• Twin Studies - Strengths

  • Consistent evidence there is relationship between genes and criminality
  • Proved MZ twins are more likely to both commit criminal acts as they share 100% DNA
• Twin Studies - Weaknesses

  • Biological determinism - assumes that individuals have no control over criminal behaviour - contradicts CJS
  • Ignores roll of environment - twins have shared environments
  • Lack of control in studies - Lange's research based on appearance not genes
• Adoption Studies - Outline

  • Allows to see difference between nature and nurture.
• Adoption Studies - Research

  • Mednick (1975) looked at 14000 adopted children. High proportion of boys with criminal convictions had criminal biological behaviour.
  • Follow up study in 1994 - no relationship between criminal convictions and adoptive parents.
• Adoption Studies - Strengths

  • Allows separation of nature and nurture to see which has larger influence.
  • Mednick's research supports that genes play a role in criminal behaviour.
  • Stronger correlation with biological parents.
• Adoption Studies - Weaknesses

  • Age of adoption could influence behaviour.
  • Research is only correlational - doesn't allow establishment of whether genes have cause of criminal behaviour.
  • Adoption process may not be random, placed in similar environment to biological environment.