Unit 2 AC 2.1 Biological theories

What did Lombroso’s theory suggest?

• Criminals are atavistic - less evolved

• They are pre social, unable to control impulses and reduced sensitivity to pain

• You can tell what crime someone will commit by the way they look

According to Lombroso, what features does a murderer have?

• Curly hair

• Bloodshot eyes

According to Lombroso, what features do sex offenders have?

• thick lips

• Protruding ears

Summarise the study conducted by Lombroso and his findings.

• Examined facial + cranial features of over 300 dead criminals + over 3000 living ones

• Found that 40% of criminal acts could be accounted for by atavistic characteristics

What are the atavistic characteristics?

• long arms

• Large ears

• High cheekbones

• Flattened or upturned nose

• Low sloping forehead

• Large or forward projection of jaw

What study supports Lombroso?

• Uni of China > ID photos of 1856 Chinese men, half of whom had a previous conviction entered into AI programme.

• wrongly flagged innocent men as criminals but correctly identified 83% of criminals.

Strengths of Lombrosos theory?

• first to study crime scientifically — objective measurements

• Showed importance of examining clinical + historical records of criminals

• By arguing they are not freely choosing to commit crime, it helps us focus on how we can prevent further offending rather than punishing offenders.

Limitations of Lombrosos theory?

• Research since has failed to support

• No control group used

• Scientific racism—identifying criminals as primitive savages equates non western societies with criminals

• Only applies to Italians

What are the 3 somatotypes?

• mesomorphic (muscular) - adventurous, assertive

• Ectomorphic (thin) - self conscious, thoughtful

• Endomorphic (fat) - sociable, relaxed

Which somatotype is more likely to engage in crime according to Sheldon and why?

Mesomorph - risk takers, muscular physique + assertiveness can be an asset for criminality.

Strengths of Sheldons somatotypes?

• Support from other studies — Glueck + Glueck > 60% of offenders were mesomorphs

• Most serious delinquents in sheldons sample were the ones with most extremely mesomorphic body shapes.

Limitations of Sheldons somatotypes?

• Glueck + Glueck - criminality is a combination of biological, psychological + environmental factors

• Mesomorphic somatotype could be a result of criminality

• Doesnt account for ecto + endo criminals

• Labelling may play a part - mesomorphs attract police attention

What does Jacob’s XYY theory suggest?

Men with an extra Y chromosome (supermales) are more aggressive.

What statistics show an over representation of supermales in prison?

• 15 XYY cases per 1000 in prison

• 1 XYY case per 1000 in general public

What did Osborn + West discover which supports genetic theories?

Fathers with criminal records are 2x more likely to have sons with criminal records than fathers who did not.

Who is a real life example of XYY syndrome?

John Wayne Gacy — killed at least 33 people

Strengths of Jacobs XYY theory?

• found association between XYY + violent offenders

• Price and Whatmore found links between the syndrome and property crime

Limitations of Jacobs XYY theory?

• XYY males are well built so fit the stereotype, therefore they are labelled + more likely to get a sentence.

• May be over represented in prison because they often have low IQ — likely to get caught.

• Rare syndrome so cant explain much crime

What is a concordance rate?

When twins share a characteristic

What did Lohannes Lange’s twin study find?

• Both twins in 10 of 13 MZ twins were criminals

• Both twins in 2 of 17 DZ twins were criminals

What did Ishikawa + Raine find?

44% crim concordance rate for MZ but only 21.6% for DZ

What is a case study that supports twin studies?

The Krays - Convicted of murder

Strengths of twin studies?

• MZ twins are identical so its logical to examine whether offending behaviour is identical

• Give some support to genetic explanations e.g ishikawa + raines study

Limitations of twin studies?

• If genes were the only cause of criminality concordance rate would be 100%. Studies only show half or less.

• Higher concordance rate between MZ twins may be due to sharing same environment

• Early studies guessed whether twins were identical based on looks - not valid

What did Hutchings + Mednick find in their adoption study?

• High proportion of boys with criminal convictions had biological parents with convictions too (20% concordance rate).

• Smaller proportion had a criminal record if their adoptive parent had one (14.7%)

Strengths of adoption studies?

• overcome problem faced by twin studies where MZ twins are brought up in the same household

• Findings show support for genetic theories

Limitations of adoption studies?

• Gottfredson + Hirschi argue that adoption studies have little effect on criminality. Adopted children are often placed in environments similar to birth family.

• Many children are not adopted immediately after birth but remain with bio family for some time

What study suggests that damage to the pre-frontal cortex causes crime?

Raine et al - used pet scans to study brains of impulsive killers. Damage found in pre frontal cortex, which controls impulsive behaviour.

Mcisaac et al - people suffering head injuries are 2x more likely to end up in prison, females even more likely

Strengths of brain abnormalities as an explanation of criminality?

• in extreme cases, brain injury or disease has led to major changes in personality + behaviour (Aaron Hernandez)

• Correlation between abnormal EEG readings and psychopathic criminality

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

Weaknesses of brain abnormalities as explanation for criminality?

• Crime caused by brain injury is very rare

• Not clear that abnormal brainwave activity causes psychopathic crime. Some psychopaths have normal EEG patterns.

• Prisoners higher likelihood of brain injury may be result of criminality

What are the biochemical explanations for criminality?

• Sex hormones

• Blood sugar levels

• Serotonin

• Substance abuse

What study suggests high levels of testosterone cause crime?

Ellis and coontz: testosterone levels peak from puberty to early 20s. Age range correlates with highest crime rate in males.

What can be accepted as partial defences for women charged with crimes ranging from shoplifting to infanticide?

• Pre menstrual tension

• Postnatal depression

• Lactation

What can cause hypoglycaemia? (low blood sugar)

Large quantities of alcohol

How does serotonin influence crime?

Studies show low levels of serotonin are linked with higher aggression levels.

What study supports low serotonin as an explanation for crime?

Scerobo + Raine: meta analysis on 29 studies into anti social behaviour found low levels of serotonin in all of them + controlling serotonin by diet is possible.

Strengths of biochemical explanations?

• sex hormones, blood sugar levels and substance abuse can effect mood, judgement and aggression.

• Ellis + coontz testosterone study

• biochem factors are recognised by courts. Partial defences for infanticide + shoplifting

Weaknesses of biochemical explanations?

• biochem processes may predispose people to offend but may require environmental triggers to cause actual offending.

• Scarmella + brown - testosterone levels do not greatly affect aggression levels in most men.

• Schalling - testosterone leads to verbal aggression, not physical.

• infanticide may be due to isolation + responsibility of caring for a newborn, not hormones.