biological explanations of crime Flashcards
describe lombrossos theory
The first physiological theory of criminality was put forward by Cesarre Lombroso (an Italian doctor) in 1876. He argued that criminals were physically different to non-criminals.
After examining the skulls of deceased criminals, and the facial features of prisoners, Lombroso proposed the ‘atavistic form’
theory of criminality. Atavistic form refers to the traits that Lombroso found to be common in prisoners and the deceased criminals.Lombroso concluded that criminals could be identifiedby their distinctive physical features, such as:
• Enormous jaws
• Large eye sockets
• Prominent eyebrow arches
• High cheekbones
Lombroso referred to criminals with any of these features as ‘atavistic’, meaning that they were not as evolved as other people.
He claimed that those who were atavistic were throwbacks to an earlier primitive stage of evolution. They were pre-social, unable to control their impulses and had a reduced sensitivity to pain (which in his view is why they had tattoos and were more likely to take risks.). Thus, he argued that criminals were like ‘savages’ or even apes. In Lombroso’s view, such people were ‘born criminals’ that we could identify
scientifically by ‘reading’ their bodies for the physical characteristics that marked them out as different
describes sheldon somatotype theory
Sheldon (1940) also saw criminals as physically different from non-criminals. In
his view, certain body types or ‘somatotypes’ are linked to criminal behaviour.
He identifies three somatotypes:
Ectomorphs Thin, lacking fat & muscle. Thin face, flat-chested and high forehead. Self-conscious and emotionally restrained.
Mesomorphs Muscular, strong limbs, and broad shoulders.Sensation-seeking,risk-taking, and domineering.
Endomorphs Round body shape, lack of muscle and wide hips.Sociable & outgoing.
Sheldon made links between mesomorphs and criminality, proposing that their physical stature is beneficial in crime, and they are more likely to engage in risk-taking behaviours than other somatotypes.
evaluate lombrosso
strengths- Lombroso was the first person to study crime scientifically, using objective measurements to gather evidence. Previously crime was seen as a moral or religious issue.
Butcher & Taylor (2007) suggest that less attractive individuals are more likely to be considered criminals.
His research showed the importance of examining clinical and historical records of criminals.
His later work took some limited account of social and environmental factors, not just heredity.
weaknesses-
Lombroso failed to compare his findings on prisoners with a control group of non – criminals. Had he done so, he may have found the same characteristics among the general population; in which case, his explanation would be invalid.
Not everyone with atavistic features is a criminal and not all criminals have them.
Scientific racism - DeLisi (2012) indicated that many of the atavistic features defined are specific to people of African descent.
Research since Lombroso has failed to show a link between facial features and criminality
evaluate sheldons theory
strengths-
- A number of other studies have confirmed that there is a small association between bodily build and criminality (Putwain & Sammons)
-Sheldon used a good-sized sample (200) and he used a control condition of non-offenders (students) to compare his results to.
-Glueck & Glueck (1956) found that in a sample of delinquents, 60% were mesomorphs, while non-delinquents, only 31% were mesomorphs.
- The most serious delinquents in Sheldon’s sample were the ones with the most extremely mesomorphic body shapes.
weakness-
-Sheldon did not explain how ectomorphs and endomorphscould also be criminal.
-Does not take into account that someone’s ‘somatotype’ is not fixed. People’s bodies change throughout their lives.
-Glueck & Glueck found that criminality was best explained through a combination of biological, psychological, and environmental factors.
- Criminals may develop a mesomorphic build as a result of needing to be physically tough to succeed. If so, criminality causes somatotypes, rather than somatotypes causing criminality.
describe twin studies
These studies focus on identical twins (monozygotic twins) who are 100% genetically identical (they both developed from the same fertilised egg). Therefore, if one twin is criminal, the other twin ought to be criminal too.
Identical twins are also compared to non-identical twins (dizygotic twins), who are not 100% identical to each other. If criminality is genetic then you would expect more identical twins to be both criminal than non-identical twins.
evidence comes from christensens study of 3586 twin pairs in denmark, found that theres a 52% concordance rate between mz twins that is where only one twin had a conviction, there was a 52% chance of the other twin having a conviction. among dz twins, there was only a 23% chance.
describe adoption studies
Researchers have also used adoption studies to test for a genetic cause of crime. These studies compare adopted children both to their biological birth parents and to their adopted parents.
The thinking behind adoption studies is that an adopted child (especially if adopted after birth) shares the same environment as their adoptive parents, but the same genes but as their biological parents.
If we find that the adoptee’s behaviour in regard to criminality is more similar to their birth parents’ behaviour, this would support a genetic explanation.
where does evidence come from for the apotion studies
mendick et al examined over 14000 adopted sons in denmark from 1924-1947.
found that sons were more likely to have a criminal record if their birth parent did too- concordnece rate of 20%
By contrast, they found that a smaller proportion had a criminal record if their adoptive parents did (14.7%)
descirbe jacob xxy study
Abnormality of the sex chromosomes is another possible genetic cause of criminality.
Chromosomes are made up of DNA and protein, and they are found in the nucleus of our cells. Chromosomes carry all the genetic information that we inherit from our parents.
We normally have 46 chromosomes, arranged in 23 pairs. We inherit half of each pair from each parent. One pair consists of our sex chromosomes and determines our biological sex of male or female.
● XX = Female
● XY = Male
However, sometimes there are abnormalities. One abnormality is an extra Y (male) chromosome. This is known as the XYY syndrome and has been labelled ‘super male syndrome’. Men with XYY syndrome tend to be tall and well built, and of low intelligence. Jacob et al (1965) claimed that men with the XYY syndrome are more aggressive and potentially violent than other males.
where does evidence for jacobs xxy study come from
came from studies of imprisoned criminals where a higher than average had xyy syndrome. many had history of aggression and violent assault. Price and whitmore found xyy males to be more immature and unstable with a strong tendency to commit seemingly unmotivated crimes.
what are biochemical explanations for crime
These include substance abuse, blood sugar levels and sex hormones.
● Substance abuse: Research has found that 80% of family violence crimes involve the misuse of alcohol.
● Blood sugar levels: Low blood sugar levels (hypoglycaemia) is linked to aggression, especially when alcohol is consumed, which is known to lower blood sugar.
● Sex hormones: High levels of testosterone are linked to aggression in men, and crimes such as rape and murder. In addition, hormone changes in females during the menstrual cycle have been linked to criminality, such as infanticide (murder of a child).
evaluate twin studies
stengths- MZ twins are genetically identical, it is logical to examine whether their offending behaviour is also identical.
- Christiansen (1977) supports the view that criminality doeshave a genetic component.
weaknesses-
-The small sample in twin studies may not be representative of the general population
-In twin studies, it is impossible to isolate and measure the effect of genes separately from environmental effects
evaluate jacobs xyy study
strengths
- One study by Jacob et al (1965) found that a significant number of men in prison had XYY sex chromosomes, instead of the normal XY.
-Alder et al (2007) indicated that it is possible that aggressive and violent behaviour is at least partly determined by genetic factors.
-Price and Whatmore (1967) found some links between the syndrome and property crime.
weaknesses-
XYY males are tall and well built, so they fit the stereotypes of ‘violent offenders’ and get labelled as such by the courts, so they are more likely to get a prison sentence. As a result, the XYY males are over – represented in samples drawn from prisoners and this overstates the importance of the syndrome as a possible cause of crime
-Alternatively, XYY males may be overrepresented in prison because they often have low intelligence, meaning they are more likely to be caught.
-The syndrome is very rare (1 in 1000 men) so it cannot explain much crime.
evaluate adoption studies
strengths- Adopted children are exposed to a different environment to their biological family, therefore it is easier to separate genetic and environmental factor
Adoption studies overcome the problem faced by twin studies, where biologically twins are brought up in the same household, which makes it impossible to separate out the influence of genes from the environment.
weaknesses-
Adopted children are often place similar environments to their birth family, (same class & ethnicity). Similar environments may produce similar behaviour.
Age of adoption may mean the adopted children have already been influenced by either their natural parents or their foster environment.
evaluate biochemical explanations of crime
