Criminology - Unit 2 Biological theories of crime

Biological theories

What are some examples of the genetic theories of crime?

XYY theory, twin studies and adoption studies.

What are some examples of physiological theories of crime?

Lombroso’s atavistic features and Sheldon’s somatotypes.

Describe XYY syndrome.

This theory suggests that people may be born with chromosomal abnormalities which creates a genetic predisposition to commit crime. Some abnormalities feature an extra Y chromosome which is identified through blood samples. XYY men are sometimes known as ‘super males’ because they are usually tall, muscular and well built due to higher levels of testosterone. This also means that men with XYY syndrome are more aggressive and more likely to be violent and criminal. This is supported by Jacobs et al 1965 study who found that 15 per 1000 men in the prison population had this syndrome compared to 1 per 1000 in the general population.

What are the strengths of XYY theory?

• It has supporting research from Jacobs et al who found that 15 per 1000 people in the prison population had XYY syndrome compared to 1 per 1000 in the general population. This is a strength as it shows a tendency to commit crime.

  • The theory is scientific as the syndrome is measured by blood samples which is an objective method. This means the theory is more valid.

What are the weaknesses of the XYY theory?

• Described as a limited theory of crime as it only focuses on violent crime and doesn’t explain other types like white collar crime. Also, it only explains males committing crime and not females.

• It is biologically deterministic. This theory says that people are destined to commit crime due to genes/chromosomes. Other theories suggest crime is a choice such as right realism. This creates problems for the CJS which is built on the notion of free will.

• Focuses too heavily on genetic factors and ignores environmental factors. We do not know if XYY is the sole cause of their violence; there may be other factors involved e.g. childhood, friends, family.

  • XYY syndrome is very rare; only 1 in 1000 men have it so it cannot explain much crime.

What is the key research for XYY theory?

Jacobs et al. (1965) found that 15 per 1000 men in the prison population have the syndrome compared to 1 per 1000 in the general population.

How do twin studies contribute to our understanding of the biological basis of crime?

Twin studies support the idea that a heritable trait may increase the risk of criminal behaviour. This is shown when concordance rates between monozygotic twins are higher than between dizygotic twins.

Give an example of a twin. study that suggests there is a genetic basis of crime.

Christiansen 1977 - studied a large sample of of over 3,000 twins from the Danish Islands and found concordance rates of 35% in monozygotic twins and 13% in dizygotic twins.

What are the strengths of twin studies?

There is a variety of supporting research that shows higher concordance rates in MZ twins compared to DZ twins. For example, Christiansen (1977) found concordance rates of 35% for MZ twins and only 13% for DZ twins. These findings suggest that crime has a genetic basis.

What are the weaknesses of twin studies?

- Twin studies do not separate nature and nurture even though twins also share the same environment. For example, they both have the same upbringing, the same education, peer group, and socio-economic status. Higher concordance rates in MZ twins may also be influenced by the fact they are treated more similarly than DZ twins. Therefore, it may be this that explains similarities in criminal behaviour, not genetics.

- The theory is reductionist. For example, if genetics was the cause of criminality, identical twins would show 100% concordance rates but studies usually show around half or less. This means there must be external factors involved that the theory ignores.

- Early twin studies were not controlled properly. This is because the decision whether twins were MZ or DZ was made on the basis of how they looked and not their DNA meaning these studies lack validity.

Who was Cesare Lombroso and how is he important in criminology?

Lombroso is seen as the father of modern criminology as he separated criminology from religious explanations and pioneered the use of scientific methods.

Explain Lombroso’s theory of criminality.

Lombroso said that criminals are a different species and that criminality is heritable. He argued that people are born criminal and can be noticed through their atavistic features. These features are throwbacks to an earlier stage of human development that manifested as a tendency to commit crimes. The behaviour of these evolutionary throwbacks does not fit into society’s expectations and so they will commit crime. Atavistic features include:

-large or forward projecting jaw

-long arms in relation to Lower limbs

-large protruding ears.

What did Lombroso’s study find?

His study found that 40% of criminal acts are committed by people with atavistic features.

What are the strengths of Lombroso’s theory?

• Lombroso was the first person to give Crim scientific credibility and use objective measurements when previously crime was seen as a moral or religious issue. For example, Lombroso measured the facial and cranial features of criminals which is seen as scientific.

What are the weaknesses of Lombroso’s theory?

• It is very deterministic and assumes that we cannot escape our destiny of committing crime. Lombroso believed criminals are born with this evolutionary throwback. This causes problems for the CJS which is based on free will.

• Goring (1913) compared 3000 convicts to 3000 non-convicts and found no significant differences in distinctive facial features. Lombrosos did not use a control group which means his study lacks validity.

• Not everyone with atavistic features is a criminal and not every criminal has atavistic features e.g. ted bundy.

  • Lombroso is accused of scientific racism - many of the atavistic features are typical of people of African descent. This theory could justify prejudiced views which can then be used to support the policy of eugenics.

Explain Sheldon’s theory of criminality.

Sheldon proposed there are three somatotypes:

Ectomorphic - thin and fragile. This is linked with being introverted, restrained and relaxed.

Mesomorphic - muscular, hard bodied, and aggressive. This is linked with being adventurous and enjoying physical activity.

Endomorphic - fat and soft. This is linked with being sociable and relaxed.

He found that delinquents had a higher mesomorphy rating on average. This means criminals prone to committing aggressive acts were mesomorphic.

What are the strengths of Sheldon’s theory?

- Contains supporting research. For example, Gluck and Gluck (1956) found that in a sample of delinquents, 60% were mesomorphic but in a non-delinquent sample, only 31% were.

- In Sheldon’s correlational research, the most serious delinquents in his sample were the ones with the most extreme mesomorphic body types.

What are the limitations of Sheldon’s theory?

- Relies on correlational research. This only shows the relationship and does not show causation. For example, it may be that testosterone is what impacts body type and it is this that causes aggression and crime.

- Body type is not fixed, it can change over time. This would not change personality type or lead to more/less criminality meaning this theory is reductionist.

- The theory is stereotypical. Because of the way people treat mesomorphs, they could be picked on or invited/dared to do illegal acts. They may therefore be drawn into criminal activities by their peer groups leading to a self fulfilling prophecy.

- The theory is reductionist. It only explains violent crimes and ignores other crimes like white collar or technological crime.

Explain brain abnormalities (brain damage)vas a theory of crime.

Several research studies have suggested that damage to the pre-frontal cortex may cause altered behaviour in individuals including immaturity, loss of self control, decision making etc. Raine (1994) found damage in the pre-frontal cortex of the brains in criminal which controls decision making. It was also found that the amygdala (emotion centre of the brain) was shrunken in teenagers with aggressive conduct disorders.

What is the main research for brain damage.

Recent research in Canada (mc Isaac et al. 2016) found that people who have had serious head injuries are twice as likely to go to prison. Female prisoners were even more likely to have survived brain injury. The risk of women who had suffered brain injuries was 2.76 higher than uninjured women.

Explain the neurochemical theory of crime.

Aspects of a person’s diet such as low blood sugar, additives in food and pollution can influence the chemistry of the brain. Research has found that low levels of serotonin is linked to aggression e.g. not eating enough salmon eggs, bananas and other food that boosts serotonin can influence criminality.

What is the main research for the neruochemical theory?

Scerbo and Raine (1993) carried out a meta analysis of 29 studies looking at antisocial adults and children. They found low levels of serotonin in all studies.

Explain the use of steroids theory of crime.

People who take steroids in large amounts can become very violent. This is known as roid rage. Steroids are taken to increase muscle growth but they also increase testosterone levels which is a hormone thought to be implicated with aggression.

What is the main research for use of steroids?

A study in Sweden calculated 32 steroids users seeking treatment and also accessed their criminal records. In comparison to other drugs of abuse, steroids use proved to be associated with a greater severity and frequency of violent crimes.

Explain the policy of diet.

This policy is based on the theory that low serotonin levels can lead to crime. In Gesch et al (2002) study, 231 male prisoners volunteered to receive either a daily vitamin, mineral and essential fatty acid supplementation or a placebo drug. The result showed the average number of disciplinary. incidents per 1000 person days dropped by 35% and in the placebo group only by 10%. This shows that it is possible for diet to positively impact aggressive behaviour which in turn may lead to less crime.

Describe the policy of chemical castration.

This policy is based on the theory that high testosterone may cause crime. It aims to lower testosterone levels and take away sexual interest. It is compulsory for sex offenders in Poland and in South Korea. In a 2012 pilot scheme, chemical castration was provided for sex offenders in Her Majesty’s Prison. Here, volunteers were given a pill to reduce their sex drive. Such treatment was positively received by the prisoners.

Describe the policy of eugenics.

This policy is based on the theory that crime can be inherited through genes. It advocates higher rates of sexual reproduction for people with desirable traits and higher rates of sterilisation of people with less desirable traits. It reinforces the ideas of biological determinism and claims that biology had contributed towards many social problems. For example, the Nazi sterilisation programme advocated the policy of eugenics. It followed that there were claims that sterilisation laws would prevent incarcerated criminals from giving birth to criminal offspring.

What is the supporting research for eugenics?

Osborn and West 1970’s found 40% of boys whose fathers had criminal records had criminal records themselves compared to just over 12% of boys whose fathers did not have criminal records.

Describe the policy of the death penalty.

This policy is linked to the theory that crime is linked to biological or innate factors. It aims to get rid of criminals but also act as a deterrent. According to Amnesty International (2017) 1032 people were executed in 2016 excluding China. In the Uk there was a temporary abolition of the death penalty in 1965. It was then permanently abolished when it was shown that murder rates did not soar. The effectiveness of this policy is questionable. This is because statistics from the USA show that murder rate is lower in states that do not have the death penalty than those that do. For instance, in 2015 the murder rate was 25% higher in death penalty states than non death penalty states.

Evaluate the death penalty as a policy of crime prevention.

strengths:

• the death penalty does guarantee the public protection from harm. Convicted murderers are incapacitated and so they cannot commit further crimes, protecting the public.

  Weaknesses:

• the death penalty has not proven to be an effective deterrent. Studies show that crime rates are lower in places that do not have the death penalty. for example, a study in 2015 showed that murder rate was 25% higher in death penalty states.

  • The death penalty can be criticised as it infringes upon human rights. It does not help rehabilitate offenders or tackle any root cause of crime. it is punitive and ignores other aims of punishment.

Evaluate the policy if diet.

• Supported by research from Gesch et al (2002). He gave over 200 male volunteer prisoners either a daily vitamin mineral and essential fatty acid supplementation or a placebo drug. Its was recorded that the number of disciplinary incidents per 1000 person days decreased by 35% and the placebo drug group only by 10.1%

  • Also supported by Virkunnen et al 1987 who found that violent offenders had a lower than average serotonin turnover.

Evaluate the policy of chemical castration.

• supported by research. a 2012 pilot scheme chemically castrated male volunteer prisoners in hmp whatton. here volunteer were given a pill to reduce their sex drive. such treatment was positively received by the prisoners.

Evaluate the policy of eugenics

• it is highly unethical and controversial. it deprives people with the right to a family life as people who have been castrated can’t have children. also, it was used in the nazi sterilisation programme where thousands of people were forcibly sterilised due to the way they look, or their mental or physical disabilities in order to build a ‘national healthy body’. this gives way to discrimination.