2.1 Flashcards
what are the 2 physiological theories?
Lombroso
Shelton’s somatotypes
describe Lombroso’s theory (1876)
- the criminal is a separate species - between modern and primitive humans.
- the physical shape of the head and face determined a ‘born criminal’
- studied and measured the bodies of executed and deceased offenders as well as examining living inmates to locate physical differences/abnormalities. (measurements, sketches and photographs of 383 dead criminals and 3839 living ones)
- found that 40% of criminal acts could be accounted for by atavistic features
- features included: enormous jaws, high cheek bones, exceptionally long arms, large eye sockets. a male marked with 5 or more of these features is marked as a born criminal.
- a born criminal is an atavism. (throwback to an earlier stage of human evolution, where they were pre-social, unable to control their impulses and had a reduced sensitivity to pain.
- the female offender- may be identified with as few as 3 anomalies. he concluded that female criminals were rare and suggested they had evolved less than men due to the inactive nature of their lives. - female criminals had more masculine features.
evaluate Lombroso’s theory
strengths
- Charles Soring found a low-order intelligence in convicts which supports atavism.
- recent Chinese study shows you can identify criminals from their facial features. ID photos of 1856 Chinese men and half had previous criminal convictions. they were entered into an AI programme and it correctly identified men as criminal 83% of the time. only wrongly flagged innocent men as criminal 6% of the time.
limitations
- didn’t use a control group to see if the same features could be found in non-criminals
- not everyone with atavistic features is a criminal and not all criminals have them
- gender bias
describe Sheldon’s somatotypes theory
saw criminals as physically different from non criminals. in his view, certain body types or ‘somatotypes’ are linked to criminal behaviour. he identifies 3 somatotypes:
- endomorphs
fat and soft. lacks muscle or tone.
sociable, relaxed
-ectomorphs
thin and fragile - lacking muscle and fat.
self-conscious, restrained introverted
- mesomorphs
muscular and hard bodied.
adventurous, sensation-seeking, domineering, aggressive
Sheldon argues that mesomorphs are the somatotype most likely to engage in crime - more attracted to the risk taking.
in a study of 200 boys at an institute, mesomorphs were more prone to delinquency.
800 delinquents compared to a matched sample of non-delinquents and found delinquents were more likely to be mesomorphs
evaluate Sheldons theory.
strengths
- reliability: Gluek and Gluek found that 60% of offenders in sample were mesomorphs compared to 31% in non delinquent sample.
- used large sample sizes
- had control group of non-offenders to compare.
limitations
- criminals may build a mesomorphic body shape as a result of needing to be physically tough to succeed - criminality caused somatotype rather than somatotype causing crim.
- doesn’t account for the endomorphs and ectomorphs that commit crimes
- labelling may play a part. mesomorphs may be labelled as troublemakers as they fit the ‘tough guy’ stereotype, resulting in a self-fulfilling prophesy, or may attract police attention and more likely to get caught than other somatotypes.
name the genetic theories
twin studies
adoption studies
Jacobs XYY syndrome
describe the twin studies
MZ twins share exactly the same genes - they both developed from the same fertilised egg. therefore if one twin is criminal, the other twin ought to be criminal too.
evidence for this comes from
Christiansen’s study of 3586 twin pairs in Denmark:
he found that there was a 52% concordance rate between MZ twins (so when one identical twin had a conviction, there was a 52% chance of the other twin also having a conviction.
- among DZ twins, there was only a 22% chance.
evaluate the twin studies
strengths
- as MZ are identical, it’s logical to say behaviour is identical.
- reliable evidence - large scale
limitations
- if genes were the only cause of criminality, MZ should be 100% concordance, but studies show around half or less.
- parents treat MZ twins more alike than DZ, so their shared environment might cause similarities in their criminal behaviour rather than genes. they also might feel closer than non-identical twins, so more likely to be influenced by the other twins criminality.
- it’s impossible to measure the effects of genes separately from environmental effects.
-
describe the adoption studies
these studies compare adopted children both to their biological birth parents and their adopted parents
adoptive child shares the same environment as their adoptive parents but he same genes as their biological parents.
so if we find that the adopted child’s behaviour in regard to criminality is more similar to the birth parents’ behaviour this would support genetic explanation.
evidence:
Mednick examined data on over 14,000 adopted sons in Denmark. they found that sons were more likely to have a criminal record if the birth parent also had a record (concordance rate of 20%)
they found that a smaller proportion (14.7%) had a criminal record if their adoptive parents had one.
evaluate the adoption studies
strengths
- adoption studies overcome problems faced by twin studies, as for that it’s impossible to separate out infringe of genes from environment.
limitations
- many children aren’t adopted straight after birth and can remain with biological family for some time, meaning they could imitate their behaviour already, and could still be environmental factors rather than genetic.
- adopted children often get put in environments similar to birth family, with families of the same class and ethnicity and in the same locality etc.
describe Jacobs XYY study
our mothers 2 two female chromosomes are known as XX and fathers XY.
because we inherit one chromosome from each parent we will have either:
- XX female
- XY male
one abnormality is an extra Y chromosome. this is known as XYY syndrome (super male syndrome).
they tend to be very tall and well built, and of low intelligence.
Jacob claimed that men with this syndrome are more aggressive and violent than other males.
this claim is based on studies of imprisoned criminals, such as those in secure psychiatric institutions, where a higher than average proportion of the inmates were found to have XYY syndrome. many had histories of aggression and violent assault.
found that 15 per 1000 in prison pop
1 per 1000 in general pop
evaluate Jacobs XYY theory
strengths
- found association between XYY and violent offenders.
- prince and Whatmore found them to be immature and unstable with a strong tendency to commit seemingly motiveless property crimes.
limitations
- even if some violent offenders have XYY syndrome this doesn’t mean it was the cause of their offence.
- very rare- only 1 in 1000 males have it so can’t explain crime as a whole.
- offers no explanation for female criminality.
- low intelligence so more likely to get caught so could be over represented in prisons
- XYY males are tall and well built, so they fit into the stereotype of ‘violent offenders’ and get labelled as such by the caught, so they are more likely to get a prison sentence. as a result, XYY males are over-represented in samples drawn from prisoners and overstates the importance of the syndrome as a cause of crime.
describe the case of Phineas gage and how it links to brain injuries and crime
1848
survived a traumatic brain injury caused by an iron rod that shot through his skull and obliterated the greater part of the left prefrontal cortex.
after he became vile and nasty. his wife said that he was a completely different person and she said he was more violent.
some studies have shown that prisoners are more likely than non-prisoners to have suffered brain injuries
prefrontal cortex is responsible for cognitive functioning such as moral decision making, impulse control and emotion regulation
describe the case of Charles Whitman in relation to brain diseases
- he killed his mother and his wife
- then shot 3 people in the uni of Texas clock tower, then opened fire at random and killed a further 11 people in a 2 hour attack.
- he had a tumour in his brain which was pressing on his amygdala- region of the brain crucial for emotion and behavioural control.
describe how brain diseases are linked with criminals
some brain diseases have been linked with criminal behaviour. e.g. senile dementia, Huntington’s disease, brain tumours.
