Biological Theories: Evaluation

Physiological theories: Lombroso - Strengths

• Lombroso was the first person to study crime scientifically, using objective measurements to gather evidence.

• Research shows the importance of examining clinical and historical records of criminals.

• Helps us to focus on how we might prevent further offending rather than simply punishing offenders.

Physiological theories: Lombroso - Limitations

• Research since has failed to show a link between facial features and criminality.

• Lombroso failed to compare his findings on prisoners with a control group of non-criminals, if he had he would of found the same characteristics among the general population.

• By describing criminals as like ‘primitive savages’, Lombroso equates non-western societies with criminals. This is a form of racism.

Physiological Theories: Sheldon - Strengths

• Other studies have replicated Sheldon’s findings

• The most serious delinquents in Sheldon’s sample were the ones with the most extremely mesomorphic body shapes.

Physiological Theories: Sheldon - Limitations

• Criminals may develop a mesomorphic build as a result of needing to be physically tough to succeed, so criminality causes somatotype.

• Social class may be the true cause both of offending. Convicted offenders are mainly working-class males, who are likely to be in manual jobs where they acquire athletic builds.

• Sheldon doesn’t account for those endomorphs and ectomorphs who do commit crimes.

Genetic Theories: Twin studies - Strengths

• Because MZ twins are genetically identical, it is logical to examine whether their offending behaviour is also identical.

• Twin studies give some support to genetic explanations.

Genetic Theories: Twin studies - Limitations

• If genes were the only cause of criminality, identical twins would show 100% concordance.

• Parents treat identical twins more alike, so one twin may be influenced by the others criminality to become criminal too.

• It is impossible to isolate and measure the effect of genes separately from environmental factors.

Genetic Theories: Adoption Studies - Strengths

• Adoption studies overcame the problem faced by twin studies.

• The research design is logical. It allows us to see the relative importance of ‘nature’ vs ‘nurture’.

• Findings give some support to genetic explanations.

Genetic Theories: Adoption Studies - Limitations

• Adoption studies show genes have little effect on criminality.

• Adopted children are often placed in environments similar to those of their birth family, similar environments may produce similar behaviour.

• Many children are not adopted immediately after birth but remain with their biological family for some time. Early environment may be the true cause of their criminality.

Genetic Theories: XYY Syndrome - Strengths

• Jacob et Al found an association between XYY syndrome and offenders imprisoned for violent behaviour.

• Price and Whatmore found some links between syndrome and property crime.

Genetic Theories: XYY Syndrome - Limitations

• Even if violent offenders have the syndrome, it doesn’t prove it is the cause of their violence.

• The syndrome is very rare so it cannot explain more crime.

• XYY males are well built, so they fit the stereotype of ‘violent offenders’ and get labelled as such by courts. As a result, XYY males may be over-represented in samples drawn from prisoners and this overstates the importance of the syndrome as a possible cause of crime.

Brain injuries and disorders: Strengths

• In a few extreme cases, brain injury or disease has led to major changes in a individuals personality and behaviour, including criminality.

• There is some correlation between abnormal EEG readings and psychopathic criminality.

• Prisoners are more likely than non-prisoners to have a brain-injury

Brain injuries and disorders: Limitations

• Crime caused by brain injury and disease are rare, the original personality is more important in whether they engage in crime.

• It is not clear that abnormal brainwave activity causes psychopathic criminality.

• Prisoners higher like hood to brain injury could be a result of their criminality rather than a cause of it.

Biochemical explanations: Strengths

• Sexual hormones, blood sugar levels and substance abuse can affect mood, judgement and aggression.

• Testosterone levels and male offending both peak around the same age, suggesting hormones affect criminal behaviour.

• Biochemical factors are recognised by the courts.

Biochemical Explanations: Limitations

• Biochemical processes may predispose some individuals to offend, but it may require an environmental ‘trigger’ to cause actual offending.

• Infanticide may be due to isolation and the responsibility for caring for a new-born child rather than hormones.

• Schalling found high testosterone levels led to verbal aggression but not physical violence.