Transcript Turning to Crime Biology

Turning to crime
Biology
Turning To Crime
Biology
Brain
Dysfunction
Genetic
Abnormality
Gender related
life expectancy
Raine
Caspi
Daly & Wilson
Biology
A third influence that may affect an individual’s likelihood of turning to crime is
biology.
When considering this influence we would include genes, hormones, neurology
and gender.
So far, a complete biological explanation is not good enough, but the interaction of some
biological predispositions with environmental influences can explain the individual
differences we see where only some ‘at risk’ individuals take the step into criminal
behaviour.
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For example: Genetic variation MAY be responsible for causing differences in an
individual’s level of aggression which may lead to violent crime. However it is unlikely we
can biologically explain crimes such as; fraud, theft, drug-dealing etc.
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Cases have been reported whereby a brain tumour has changed the personality
of an individual from a well-behaved caring person to a violent and uncontrolled
individual.
Biological: Brain Dysfunction
Adrian Raine conducted research using PET
scanning and found abnormalities in some
parts of the brain in violent criminals.
He has found that low physiological arousal,
birth complications, fearlessness and
increased body size are early markers for later
aggressive behaviour.
His explanation is considered to be a Bio
psychosocial explanation.
Put your thinking caps on!
Hippocampus
Thalamus
Learning &
memory
Learning &
memory
Memory &
thinking
Mental disorders
Prefrontal
cortex Emotions
Amygdala
Cerebellum
Earlier work by Raine and others had demonstrated the relationship between low
levels of activity in the prefrontal cortex and violent behaviour (Raine 1994).
This is an area of the brain behind the forehead and Raine describes the function
of this part of the brain as like ‘the emergency break on behaviour’, which
prevents us from acting on violent or aggressive impulses.
It is thought that the prefrontal cortex sends messages to the limbic system to tell
us to fear the consequences of acting on our impulses. The limbic system is part
of the old brain which governs our emotional and aggressive impulses. The
hippocampus (remember Maguire) and amygdale are key structures in the limbic
system.
Raine suggests that violent offenders have shown abnormalities in these areas in
the function of the different hemispheres (remember Sperry) and developments
of brain imaging techniques have allowed research to be carried out into the
possible brain dysfunction in violent offenders.
Evaluating Raine’s evidence for
explanations into criminal behaviour
Raine’s more recent work has led him to believe that biological predispositions are
‘switched on’ by environmental conditions. If these environmental conditions do not
exist, then the child is much less likely to turn towards crime.
What does this suggest about crime prevention?
A major concern about all biological explanations is the labelling effect.
Why is this important in relation to ethics and what can this effect lead to within
individuals?
What types of crime can’t be explained by this theory?
Evaluating Raine’s evidence for
explanations into criminal behaviour
APPROACHES
How does Raine’s study link to the physiological approach?
DEBATES
How does Raine’s study link to the nature/nurture debate?
How does Raine’s study link to the reductionism/holism debate?
Biology: Genes and Serotonin
• Genetic explanations of criminal behaviour have ranged from the “XYY
Theory” of the 1960s to the twin studies of the 1970s.
– it was proposed that males with an extra Y chromosome (males should have one
X and one Y chromosome) were predisposed to be violent criminals (Price et al.,
1966). This genetic abnormality became known as 'the supermale syndrome';
individuals who had it were above average height and below average
intelligence. The XYY theory offered the prospect.
• The XYY theory offered the prospect of a genetic explanation, which
carried with it the weight of scientific knowledge and potentially offered
possibilities of screening people before they had committed a crime,
cutting the risk to the population at a stroke. However, later research
failed to find more than low correlational support for the original
findings. The over-representation of XYY individuals in prison populations
may have had more to do with their lower intelligence, making them
more likely to get caught and to have suffered poor educational
performance, which in itself is a risk factor for becoming criminal.
Turning to crime
Biology: Genes and Serotonin
• Researchers have searched for genetic explanations for criminality by
looking at how crime runs in families.
The most common way to do this is to work with identical twins.
• Christiansen (1977) found a 52% concordance rate for criminality in MONOZYGOTIC twins
and 22% in DIZYGOTIC - but this study was fraught with reliability issues.
• However, we must remember the effects of shared upbringing and if crime really was
genetic we would expect a 100% concordance rate for monozygotic twins as they share
100% of their genes.
• A totally biological explanation would be seen as reductionist; an
advantage of this being that it can give an understanding of the cause of
behaviour, but is missing out on the complexity of human nature.
Biology: Genes and Serotonin
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Further research suggests that Monoamine oxidase (MAO) is an enzyme in the
mytochondria (the powerhouses found in large numbers in every cell that provide the
cell with energy). MAO is the enzyme responsible for breaking down several
neurotransmitters (brain chemicals which relay, amplify, and modulate signals between
a neuron and another cell) including monamines: serotonin, dopamine and
norepinephrine.
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Therefore it also has an effect on the levels of these neurotransmitters in the body.
There are actually two MAO enzymes, MAOA and MAOB, and they are produced by two
different genes that have loci (or “addresses”) close to each other on the short end of
the X chromosome. This means that these genes are sex-linked.
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It is well known medically that inhibiting the production of MAO, particularly MAOA,
using drugs is a very effective way of treating depression. So, by inference, it would
seem that altering MAO enzymic activity can affect the brain by altering its chemistry.
Evaluating Caspi’s evidence for
explanations into criminal behaviour
Sample:
Can this study be generalised?
How is this study reductionist?
How is the study determinist?
Biology: Gender
• The final study concerning biology (and
turning to crime – woop!) is an evolutionary
explanation for human behaviour.
• This assumes that behaviour has an adaptive
quality which means it is more likely that it
will be passed on biologically as it is a quality
that will aid survival.
Turning to crime
Introduction to the world of
Evolutionary Psychology
Read the section on Gender on page 30.
1. How do evolutionists explain risk-taking
behaviour in males?
Evidence 1: Evaluating Daly & Wilson’s evidence for
explanations into criminal behaviour
What is a problem in using correlation to
explain criminal behaviour?
Can the results be generalised?
Does this theory explain gender differences?
Evidence 1: Evaluating Daly & Wilson’s evidence for
explanations into criminal behaviour
How is this study reductionist?
How is this study determinist?
How is this study linked to the nature/nurture
debate?