Criminal Psychology - What Makes a Criminal? (Biological) Flashcards
Background;
Physiological explanations of crime:
Brunner (1993) – The warrior gene
A case study on a Dutch family was carried out to investigate biological explanations of crime. Within the study, 5 males were affected by borderline mental retardation and abnormal violent behaviour. The males exhibited criminal behaviours such as arson, rape and exhibitionism.
Numerous urine samples were taken and analysed from the sample over a period of 24 hours.
From these samples, a mutation in the X chromosome was identified, which explained why no females were affected as the XX genetic make-up counteracted the mutation. Brunner also found disturbed monoamine (MOA) metabolism associated with a deficit of MOA. MOA is involved in serotonin metabolism, and thus Brunner concluded that the impairment of this gene was the cause of the disturbed metabolism which then lead to mental retardation as well as their aggressive behaviour.
However, it is important to point out that not all males in the family were affected by violent behaviour, even when they suffered with mental retardation. In addition, this is an extremely rare condition and even if it were responsible for the criminal behaviour, it would be very difficult to generalise the findings.
Dabbs: To investigate the link between testosterone and crime
Two groups were created – male prisoners who had committed violent crimes and male criminals who had committed non-violent crimes. Saliva swabs were taken in order to measure testosterone levels.
The researchers found that inmates who committed crimes of sex and violence had higher testosterone levels than inmates that were jailed for property crimes or drug abuse. In addition, they found that inmates with higher testosterone levels were more involved in open confrontation whilst in prison.
Dabbs et al. say that high testosterone is associated with a lack of control over emotions, as well as aggression and violence. The higher testosterone suggests that males are more likely to commit crimes more than females due to that fact that males have higher levels of testosterone compared to females.
The following areas of the brain form an integral part of the Raine research.
The amygdala has been found to be responsible for feelings of fear. People with high activity in the amygdala have displayed impulsive aggression. However, people with reduced grey matter in the amygdala have been found to be more psychopathic, in the sense that they lack empathy and are very calculated.
The corpus callosum is responsible for transferring information from one hemisphere to the other. This could mean linguistic ability becomes impaired. This is because the left hemisphere is responsible for language! Remember this from the Sperry study?
The angular gyrus is involved in language and making sense of information. Therefore, if there is reduced functioning of this part of brain it may result in crime as criminals may not effectively understand the impact or consequences of their behaviour.
The pre-frontal-cortex is associated with emotional processing and control. People with damage to this part of the brain have less self-control, can be more aggressive, and they may find it difficult to deal with their emotions. This could lead an individual to lash out.
The limbic system AKA the emotional nervous system is made up of the amygdala, hippocampus and thalamus. Damage to this area has been linked to aggression, problems with memory, learning and attention. This could be why criminals fail to learn from their mistakes i.e. there is a very high reoffending rate for those who have been to prison, which would support this theory.
Different types of brain scans:
PET (Positron Emission Tomography) Patients are injected with a slightly radioactive glucose i.e. sugar. The most active brain tissue uses the glucose so it attracts the radioactive substance. The scan is usually presented as a coloured image where hot colours such as read and orange represent lots of brain activity whereas cold colours such as blue and green represent less brain activity. Therefore, this brain scan is more appropriate when you are trying to investigate the brain activity of certain areas of the brain.
MRI (Magnetic Resonance Imaging) Most of the human body is made up of water molecules, which consist of hydrogen and oxygen atoms. At the centre of each hydrogen atom is an even smaller particle called a proton. Protons are like tiny magnets and are very sensitive to magnetic fields.
When you lie under the powerful scanner magnets, the protons in your body line up in the same direction, in the same way that a magnet can pull the needle of a compass.
Short bursts of radio waves are then sent to certain areas of the body, knocking the protons out of alignment. When the radio waves are turned off, the protons realign. This sends out radio signals, which are picked up by receivers. These signals provide information about the exact location of the protons in the body.
They also help to distinguish between the various types of tissue in the body, because the protons in different types of tissue realign at different speeds and produce distinct signals. In the same way that millions of pixels on a computer screen can create complex pictures, the signals from the millions of protons in the body are combined to create a detailed image of the inside of the body.
This scan is more appropriate in highlighting tumors, or when you are trying to see the size or amount of grey matter in parts of the brain.
fMRI (Functional Magnetic Resonance Imaging) uses the same technology as an MRI, but instead of creating images of organs and tissues like MRI, an fMRI looks at blood oxygen levels in the brain to detect areas of neural activity. When a brain area has more neural activity it consumes more oxygen and to meet this increased demand blood flow increases to the active area. fMRI can be used to produce activation maps showing which parts of the brain are involved in a particular mental process.
During an fMRI scan the patient could be asked to perform a specific task to increase oxygen-rich blood flow to a certain part of the brain. Such as tap their thumb against their fingers, look at pictures, answer questions on a screen, think about actions based off a picture (ex: they see a picture of a book and think about actions like read a book, write a book, buy a book), etc. For the tasks where the patient is asked a question, most of the time the patient is told to just think about the answer, that way the speech part of the brain is not activated as well.
The primary reason for an fMRI scan is to help map a patient’s brain before they go into brain surgery. Creating this map will help doctors better understand the regions of the brain linked to critical functions such as speaking, walking, sensing, or planning. The brain activity is mapped in squares called voxels, which represent thousands of neurons. Colour is then added to the image to create a map of the brain, so that it is easy to see what parts of the brain were active during certain tasks.
Key Research;
The key research by Raine et al. has aimed to investigate brain activity in murderers and non-murderers using PET scans. The sample consisted of 39 M and 2F charged with murder or manslaughter but had pleaded NGRI.
The control group of 41 participants were matched on age and gender. The procedure was a Natural experiment. Continuous performance task (CPT) 30
seconds before being injected with a fluordeoxyglucose tracer for the PET scan. CPT task lasted 32 minutes while the scan was occurring. The results showed that the Murders had less activity in the prefrontal cortex of the brain compared to the controls. The conclusion of this is that Areas of abnormal activity associated with aggressive behaviour =amygdala, hippocampus and thalamus, a lack of fear =amygdala, impulsiveness (pre frontal cortex) and problems with controlling and expressing emotions = amygdala, hippocampus and pre frontal cortex.
Applications;
Plastic surgery for prisoners is one application that could help criminals to re-establish themselves into everyday lives. As it is in our society people who are deemed ugly are more likely to be seen as the villians (the ugly sisters in cinderela movies). If people who are deemed as ugly are seen in a stereotyped way can this lead to predetermining their lives? Plastic surgery therefore could be an example of how to help released criminals with getting on with their lives. It can pottentially lead to a happier life and higher self-esteem meaning that the individual may be less likely to act out criminal behaviour. In the same way changing the name and the location of previous criminals can help for them to get re-established in their new lives without the stigmas from their previous lives following them. One example of this is with Marry Bell a young child who in the 1960s strangled two young boys at the age of 11. She has been granted life-long anonymity making her wherabouts and name unknown to the world leaving her old life behind.
