Biological Theories

• Biological theories of criminality assume that criminals are biologically different, which is what makes them commit crime
• There are two types of biological explanations of criminality:

  • Physiological theories focus on criminals' physical characteristics. Genetic theories see criminality as inherited
• Lombroso's Born Criminal Theory:

  • In 1876, Italian doctor Cesare Lombroso argued that criminals were physically different from non-criminals
  • Lombroso identified criminals by distinctive physical features like large jaws, high cheekbones, handle-shaped ears, prominent eyebrow arches, exceptionally long arms, large eye sockets, dark skin, and curly hair
  • Different types of criminals were associated with specific features, e.g., murderers with 'aquiline' noses, thieves with flattened noses, and sex offenders with 'fleshy lips'
  • Lombroso described criminals as atavistic, genetic throwbacks to an earlier primitive stage of evolution, unable to control impulses and with reduced sensitivity to pain
• Lombroso believed criminals were like 'savages' who turn to crime because they can't cope with the demands of civilized society
• Physiological theory suggests that specific brain function links to criminal behavior
• According to Sheldon's Somatype theory, neurological abnormalities can be linked to criminal behavior
• Neurological abnormalities explanation:

  • Specific brain function related to the prefrontal cortex suggests that reduced activity can lead to criminality
  • The prefrontal cortex is primarily concerned with impulse control, so any abnormalities can lead to criminal behavior as the individual isn't as able to control their actions
  • Dysfunction in the prefrontal cortex is highly associated with antisocial personality disorder (psychopathy), leading to reduced emotional responses and a lack of empathy
• Concordance rate is the probability that if one twin has a characteristic, the other twin will also have the same characteristic
• Examples of concordance rates:

  • Blue eyes: 100% for MZ twins & 50% for DZ twins
  • Brown hair: 100% for MZ twins & 50% for DZ twins
  • Type 1 diabetes: 53% for MZ twins & 11% for DZ twins
  • Criminality (males): 35% for MZ twins & 13% for DZ twins
  • Criminality (females): 21% for MZ twins & 8% for DZ twins
• Types of twins

  • Monozygotix (MZ) identical 100% DNA shared
  • Dizygotic (DZ) 50% DNA shared