Lombroso's theory of atavistic features in criminals

Cesare Lombroso, a pioneer in positivist criminology during the late 19th century, proposed that criminal behaviour is determined by physical characteristics rather than free will. His work focused on identifying specific traits that he believed were more common among criminals compared to non-criminals.

Key ideas of Lombroso's atavistic theory

• Physical characteristics as indicators - Lombroso studied the appearances of criminals, often post-mortem, to find distinguishing features.
• Atavistic form - He suggested criminals possess primitive or 'atavistic' traits, such as a strong jaw, heavy brow, drooping eyelids, large or lobeless ears, high cheekbones, a flat nose, long arms, and sloping shoulders.
• Evolutionary throwback - These traits were seen as evidence of a genetic regression to earlier, less evolved human forms, driving primitive instincts that lead to criminal acts.
• Typology of criminals - Later, Lombroso linked specific combinations of features to types of crime, for instance, suggesting murderers often had bloodshot eyes and curly hair.

Evaluation of Lombroso's theory

• Strengths:
  • Introduced the idea of biological influences in criminology, shifting focus from purely moral or social explanations.
  • Recognised the interaction of biological, psychological, and social factors in criminal behaviour, influencing modern multidisciplinary approaches.
• Limitations:
  • Lacked a control group of non-criminals to confirm if atavistic features were unique to offenders.
  • Many in his sample might have had psychological disorders or genetic conditions that could explain their behaviour, rather than just physical traits.

Genetic basis for criminal behaviour through adoption and twin studies

Research suggests that genetics may play a role in predisposing individuals to criminal behaviour. Studies involving adopted children and twins provide evidence for a hereditary component, though not as the sole factor.

Evidence from adoption studies - Mednick et al. (1984)

• Method - Analysed criminal records of 14,500 Danish adoptees, comparing conviction rates with both their biological and adoptive parents.
• Results - Found that 13.5% of adoptees with no criminal parents (biological or adoptive) had convictions, compared to 14.7% with at least one convicted adoptive parent, 20% with at least one convicted biological parent, and 24.5% with both types of parents convicted.
• Conclusions - Indicates a stronger genetic link, as the highest conviction rates were among those with criminal biological parents, though rates are low overall, suggesting other influences.
• Evaluation - Adoption studies help isolate genetic from environmental factors. However, lack of conviction does not mean absence of criminal acts, which may skew results.

Evidence from twin studies

Twin studies have shown a correlation between genetic makeup and aggression levels, which some psychologists argue can contribute to offending behaviour.

Neural explanations linking brain dysfunction to offending behaviour

Biological explanations extend beyond genetics to include brain structure and function. Research has explored how dysfunctions in specific brain areas might predispose individuals to violent or criminal acts.

Brain dysfunction - Raine et al. (1997)

• Method - Used positron emission tomography (PET) scans to examine brain activity in 41 murderers (who pleaded not guilty by reason of insanity) compared to 41 matched control participants.
• Results - Murderers displayed lower glucose metabolism in regions like the prefrontal cortex, superior parietal gyrus, and corpus callosum, alongside uneven activity between brain hemispheres, indicating dysfunction.
• Conclusions - Suggests a connection between brain abnormalities and a tendency towards violence, supporting a biological basis for some criminal behaviour.
• Evaluation - Strength lies in using a matched control group for comparison on factors like age and sex. However, the inability to randomly assign participants to groups limits conclusions about cause and effect.

Chromosomal abnormalities and their potential role in criminality

Certain genetic anomalies, particularly in sex chromosomes, have been investigated for their association with criminal behaviour, focusing on how they might influence traits linked to offending.

The extra Y chromosome hypothesis - Jacobs et al. (1965)

• Method - Compared the prevalence of the XYY chromosome pattern in a prison population to that in the general population.
• Results - Discovered a higher incidence of XYY among prisoners, initially linking the extra Y chromosome to increased testosterone and aggression.
• Conclusions - Later research shifted focus, suggesting that XYY individuals may exhibit hyperactivity, impulsivity, and lower intelligence quotient (IQ), which could better explain tendencies towards criminality rather than direct aggression.
• Evaluation - While intriguing, the link is not definitive, as many XYY individuals do not engage in criminal behaviour, indicating other contributing factors.

Strengths and limitations of biological explanations for offending behaviour

Biological theories offer valuable insights into the potential roots of criminality, but they are not without criticism.

Strengths of biological explanations

• Empirical support - Numerous studies, such as those by Raine, provide evidence for biological contributions to offending behaviour.
• Scientific testing - Many biological theories can be investigated through measurable, objective methods like brain scans or genetic analysis, enhancing reliability.

Limitations of biological explanations

• Incomplete concordance - No study shows a perfect match in criminal behaviour between identical twins or biological relatives, indicating environmental factors also play a significant role.
• Indirect influences - As noted by Andrews and Bonta (2006), genetic links might reflect inherited traits like emotional instability or mental health issues, which indirectly lead to crime rather than directly causing it.
• Reductionism and determinism - Critics argue that focusing solely on biology oversimplifies complex human behaviour and suggests individuals lack control over their actions, ignoring social and personal influences.