AQA B A2 PSYCHOLOGY: FORENSIC: Explanations of Criminal Behaviour
Biological / Physiological /Genetic Explanations
Sheldon’s Somatotypes









William Sheldon believed that people could be classified into three body shapes, which correspond with three different personality types.
1.
endomorphic (fat and soft) tend to be sociable and relaxed.
2.
ectomorphic (thin and fragile) are introverted and restrained
3.
mesomorphic (muscular and hard) tend to be aggressive and adventurous.
using a correlational study, found that many convicts were mesomorphic, and they were least likely to be ectomorphic (Sheldon et al 1949).
criticised on methodological and subjective grounds (because he rated his subjects' body types himself)
supported in the area of criminal behaviour by Glueck and Glueck (1956) - found in sample of delinquents 60% were mesomorphs, whilst in a non-delinquent
sample only 31% were, and by Cortés and Gatti (1972) who found in a sample of 100 delinquents that 57% were mesomorphic compared with 19% of controls.
Wadsworth (1979) found that British delinquents who committed serious crimes tended to be smaller than average and were late in reaching puberty!
West and Farrington (1973) found no association between delinquency and body shape or size.
Feldman (1977) –expectancy - such features might catch the attention of police or influence juries or sentencing. The mesomorph is more likely to use
aggression because size is on their side.
Thornton (1939) showed 20 photographs of criminals to people who were asked to choose one of four crimes each of the criminals might have committed. He
found that people could match faces to crimes more reliably than would have been predicted by chance. Bull (1982) achieved similar results, using photographs
of non-criminal individuals but still producing an association between some faces and some crimes, which was stronger than could have been predicted by
chance.
Masters and Greaves (1969) surveyed the incidence of facial deformities in 11,000 prisoners and concluded that 60% of them had facial deformities by
comparison with 20% in a non-criminal population.
Lombroso








Lombroso in 1876 argued that the criminal is a separate species between modern and primitive humans
physical shape of the head and face determined the "born criminal" - primitive and were unable to adapt to modern morality.
based on genetics. The atavist (primitive genetic form) and had large jaws, high cheek bones, large ears, extra nipples, toes or fingers, and were insensitive to
pain.
suggested that from the surveys carried out in prison, could detect physiological differences between different types of criminal.
 murderers - cold, glassy, blood-shot eyes, curly, abundant hair, strong jaws, long ears and thin lips,
 sex offenders - glinting eyes, strong jaws, thick lips, lots of hair and projecting ears.'
indirect support from Goring (1913) - studied 3000 English convicts - a common factor in his subjects was low intelligence. At this time intelligence was
regarded as genetically determined and so criminal behaviour too was seen to be linked to genetic inheritance. Within such a reductionist biological determinism,
characteristics such as intelligence and criminality are seen as fixed and immutable. Any possibility of social factors influencing outcome is minimised. From this
perspective it is a short step to compulsory sterilisation of those who are deemed immoral' or mentally deficient, a policy which not only existed in Nazi
Germany, but in Sweden, Britain and the USA (see Rose et al., 1984).
Criticisms - research methodology was not rigorous (no proper control group, often relying on large groups of soldiers, and his criminal samples contained large
numbers of the mentally disturbed)
correlation does not imply causality. It could be that poverty and deprivation produce physical defects, rather than the defects being the result of genetic
transmission.
A study that involved giving prisoners plastic surgery in America, found that they were less likely to commit crimes upon release (Kurtzberg et al, 1978).
XYY Syndrome




Jacobs et al (1965) suggested that men with the XYY syndrome were more aggressive than normal 'XY' men. XYY men are over-represented in the prison
population. There are 15 sufferers per 1,000 in prisons and 1 per 1000 in the general population.
XYY men have lower intelligence and it could be this that leads to aggression.
A Danish study screened 4591 men for the presence of XYY - found only 12 cases (Witkin et al., 1976). Whilst these individuals were indeed more likely to be
involved in crime than chance would have predicted (41.7% of them, by comparison with 9.3% of the XY individuals), it was not involvement in violent crime.
Their conclusion was that the over-representation of XYY males in prisons and special hospitals was more likely to be the result of other characteristics - low
intelligence and above-average height - and the social reaction that these characteristics may have produced.
Some men thought to have the XYY syndrome have later been found to be XY, causing problems with studies. Key symptoms of XYY are being unusually tall and
suffering from acne and scars; some men have been incorrectly classified as XYY on this evidence alone.
Page 1 of 6
AQA B A2 PSYCHOLOGY: FORENSIC: Explanations of Criminal Behaviour

Another chromosome theory is the 'long Y' theory. Individuals with an elongated Y chromosome were higher on a delinquency scale.
Neurochemical explanation




The chemistry of the brain can be affected by environmental as well as genetic factors. Lower levels of serotonin have recently been blamed for anti-social
behaviour. Low levels of serotonin have also been blamed for depression and eating disorders. Serotonin is linked to control or inhibition of behaviour.
The brains chemistry can be influenced by diet, for example, food additives, pollution or hypoglycaemia (low blood sugar levels associated with forms of
diabetes). Dawn Stanton attacked her husband with a knife when hypoglycaemic. But not all diabetics without insulin act criminally.
Individuals with low serotonin levels, who also do not eat (and therefore their blood glucose levels drop) are more susceptible to impulsive behaviour at that
time. One study has found a link between low blood glucose levels and arson.
David Garabedian worked with strong pesticides and attacked and killed a woman where he was working. He was a quiet man who changed after the influence
of the chemicals. The reason for the change was an increase in acytecholine in the hypothalamus. Brain chemistry in itself is not a sufficient explanation to
account for all types of criminal behaviour.
Hormones


Individuals who take large amounts of steroids can become extremely violent (known as "roid rage"). Steroids, usually taken to increase muscle growth, also
increase testosterone levels. Horace Williams, a body builder, beat a man to death after taking two thousand times the recommended dosage of steroids.
Correlational studies looking at the relationship between aggression and levels of testosterone have tended to give conflicting findings; some show positive
correlations, others negative correlations or no correlation.
Neurophysiological




When Charles Whitman killed 21 people during one day in 1966 shooting 16 of them from a Texas university tower an autopsy subsequently revealed that he
had a large brain tumour, which might have been affecting the area of the brain responsible for controlling aggressive, urges, the amygdala. Such conditions or
serious brain injuries may cause dramatic personality and behavioural changes which can result in the acting out of violent impulses. In the 1970s, it was
suggested that surgical intervention in such cases might he beneficial (Delgado, 1969) though ideological objections to such drastic and often irreversible action
were legion. However, this did not prevent Mark and Ervin (1970) suggesting that brain dysfunction related to focal lesion was the cause of violence and should
be treated by psychosurgery.
Another suggestion is that certain individuals, as a result of genetic predisposition or brain damage at birth, suffer from a cluster of symptoms which render
them incapable of moral control and because of cortical underarousal, they are constantly seeking stimulation. The symptoms appear in early childhood and are
subsumed in the term attention deficit hyperactivity disorder (ADHD). They include inappropriate degrees of inattention, impulsiveness, challenging behaviour and
hyperactivity. The symptom cluster is also known as MBD or minimal brain dysfunction.
Moir and Jessel (1995) have suggested that this brain dysfunction can account for impulsive and seemingly irrational crimes, some of which involve violence.
Moreover, they suggest that brain scans could identify the disorder in young children who are already showing behavioural problems and that treatment (Ritalin
(a stimulant), biofeedback and parental training) could possibly prevent these children growing up to be seriously antisocial.
Another neurological disorder, developmental co-ordination disorder or dyspraxia, has also been seen as a possible contributor to antisocial behaviour. Sufferers
will typically tend to be clumsy and accident prone, slow to reach milestones, uncoordinated and unpopular because they do not fit in. If these symptoms are
not recognised and addressed then the social consequences of ostracism may lead to seriously disruptive behaviour. When Madeline Portwood, an educational
psychologist, assessed a group of young offenders she found that 61% of them were dyspraxic and yet none of them had been diagnosed as such (Portwood,
1996).




There are serious problems ahead if young children are to be labelled as potential criminals, and this kind of biological determinism often fails to take into
account the complexity of criminal behaviour and how it is socially constructed.
2000 persistent offenders in Canada were studied. 90% were found to have minor damage in the frontal or temporal regions of the brain (Yeudall, 1982).
Raine 1994 used PET scans to study the living brains of impulsive killers. Damage was found in the pre-frontal cortex, which controls impulsive behaviour. The
task used involved sustained attention. It involved watching a screen for 32 minutes and responding every time a 0 appeared. Impulsive individuals also missed
many of the 0s. Oddly enough, pre-frontal under arousal has also been found in politicians!
It could be that criminals have a left hemisphere that is poorer at processing Verbal information. Therefore they might make poor use of verbal code (or self
talk) and have less development of social rules (conscience).
Hare (1970) has found that 14% of aggressive psychopaths showed slow wave activity in the temporal lobe of the brain compared to 2% of the general
population. We cannot be sure whether the slow wave activity causes a person to become psychopathic or whether being psychopathic produces slow wave
activity.
Page 2 of 6
AQA B A2 PSYCHOLOGY: FORENSIC: Explanations of Criminal Behaviour

EEG readings taken of 600 Swedish children with no history of delinquency. 12 years later those with slow brain wave patterns were more likely to have had a
criminal record (Mednick et al 1981).
Low intelligence

There is no clear link between low intelligence and criminal behaviour, or at least no direct link. Low intelligence could lead to failure at school and the
consequent drifting away from what is for many a route to a successful career. Failure at school could lead to low self-esteem. This leads to emotional
disturbance, conduct disorders and criminal behaviour. The average IQ of criminals is 92, which is just below average. Remember IQ probably reflects schooling
rather than innate 'intelligence'.
Conclusions on biological explanations


The evidence does not prove that criminals are born that way.
The evidence can still be explained in terms of a poor environment. It may suit politicians to believe in biological explanations, as the cure could be simpler
and cheaper than accepting that poverty and a poor environment are major determinants of criminal behaviour. Setting to rights the ills of society could be
politically and financially difficult. Drugs and surgery have dealt with genetic problems in the past. In the earlier part of the 20th century, the eugenics
movement led to 27 US states having compulsory sterilization of the feeble minded. The Nazis killed those whom they deemed to possess an inferior genetic
makeup.
Genetic - Twin Studies




An 'MZ apart' study is when two monozygotic children have been brought up apart. If both turn out to be criminals then this would be support for the genetic
explanation. The degree of similarity between two twins is known as the concordance rate. This rate can then be compared with dizygotic twins who are
brought up together ('DZ together').
Looking at a number of studies the average concordance rate is 55% for MZ twins and 17% for DZ twins (Bartol, 1999).
Evaluation
1.
Different studies define criminality in different ways.
2.
Quasi-experimental designs are not so controlled as experimental designs.
3.
Age of separation of MZ twins.
4.
Misclassification of twins as MZ or DZ.
5.
MZ twins look alike and may therefore generate more similar social responses than DZ twins. This means that in addition to sharing the same genes,
they may also share an almost identical social environment.
6.
MZ twins often have a very close relationship and may therefore develop similar interests, which might include criminal behaviour.
7.
Very small sample size in some studies, because of the inherent difficulties in obtaining access to criminal twins.
8.
Variable definitions of criminal behaviour.
Recent studies looking at measures of personality and intelligence in relation to MZ twins reared apart have found some striking similarities (Bouchard et al.,
1990).
Genetic - Adoption Studies





1.
If a child who has criminal parents is adopted and later the child becomes a criminal then this will lend support to the genetic explanation.
A study by Schulsinger (1972) found that only 3.9% of such children developed criminal tendencies. This was compared with control children (adopted children
from non-criminal biological parents), where 1.4% became criminal. The small difference was not significant. The sample was large at 57, so there was a good
prospect of detecting significance. The psychopathy was loosely defined as impulse-ridden behaviour.
Crowe (1974) found that in a sample of 52 adopted children of imprisoned women; seven of them had at least one criminal conviction, by comparison with only
one in a matched control group.
Mednick et al (1987) found 14,000 adoptees amongst court convictions. Many had criminal biological parents (particularly strong relationship for sons and
fathers). There was no relationship in the types of crime committed. Improved social conditions reduced crime (going against the genetic explanation).
Evaluation
1. Age of adoption
2. Amount of contact with biological parents (contamination effect)
3. Adoptive family selected to be similar to biological family.
Small sample sizes.
Page 3 of 6
AQA B A2 PSYCHOLOGY: FORENSIC: Explanations of Criminal Behaviour
Psychological Explanations
Personality Theories




Extraverts need excitement so they are more likely to seek crime in order to
gain excitement.
Eysenck (1977, 1982) proposed that extraverts do not condition easily. Whereas
others would learn that crime does not pay through classical and operant
conditioning, the extravert would not learn these associations.
Gray (1981) has revised Eysenck's theory.
A third dimension was added; psychoticism. Those high in psychoticism are
'egocentric, aggressive, impulsive, impersonal, cold, lacking in empathy and
concern for others, and generally unconcerned about the rights and welfare of
other people' (Eysenck 1982).
Eysenck predicted that criminals would score highly on extraversion, psychoticism
and unstableness (Eysenck 1977). Much research has been generated in attempts
to verify Eysenck’s prediction that criminals should achieve high scores in E
(extraversion), N (neuroticism) and P (psychoticisin). Whilst there has been some
support for an association between P scores and criminal behaviour, there has
been little support for the configuration of E, N and P scores. Moreover, there
has been serious criticism of the authority with which this particular theory has
been presented when there are misgivings on any evidence for its theoretical
foundation (Trasler. 1987). Also, there is little evidence to support unstableness
or emotionality and crime. However, Eysenck has provided a testable theory that
has stimulated international research.
Moffit (1993) identified four types of young male offender:
Stable early-starters (ES)
Adolescent-limited (AL)
Adult-starters (AS)
Discontinuous offenders (DO)
Start offending from an early age and commit many
crimes. Childhood problems and low IQ
less violent than ES; have social skills to succeed in
later life
Unusual. Non-violent offences. No childhood
problems. More likely to be females (Kratzer and
Hodgins, 1999)
Crimes appear for a limited period only
Psychoanalytic Theories


The central concept of psychoanalysis, and the one that Freud first put forth, is the unconscious - traumatic experiences in early childhood left their mark on
the individual despite the fact that the individual was not aware of these experiences.
Viewed personality as having three components:
 Id - drives, animal instincts, pleasure driven
 2.Ego - balancing mechanism that mediates between id and superego
 Superego - conscience, internalised norms and values of society.
 Humans are naturally id driven and antisocial - criminal.
 Natural tendency towards crime is controlled by society - superego.
 Overdeveloped superego may contribute to criminal activity:
 commit crimes due to unconscious desire to be punished.
 repressed instincts can break through.
 Crime is a product of an ‘imbalance conflict’ between id-ego-superego
Page 4 of 6
AQA B A2 PSYCHOLOGY: FORENSIC: Explanations of Criminal Behaviour





Product of social environment - some environments may support criminality (Aichhorn, 1935).
Problems in socialisation lead to behavioural problems.
John Bowlby (1946) (see Hodges and Tizard) studied 44 juvenile delinquents and compared them with non-criminal disturbed juveniles. 39% of the delinquents
had experienced complete separation from their mothers for six-months or more during the first five years of their lives compared with 5% of the control
group. Problems with Bowlby's research: unrepresentative samples, poor matching for control group, low reliability in the interviews with participants (Feldmann
1977). Also whether or not the effects are reversible are contested (see Hodges and Tizard). Koluchova (1976) studied a pair of Czech twins and reported that
although they were severely neglected for the first 7 years of their lives they were deemed normal by the time they were 14 after being cared for. Clarke and
Clarke (1976) studied children from deprived backgrounds using a longitudinal study and found there were many factors that contributed to the child becoming a
criminal, not just whether or not they were maternally deprived.
Psychoanalytic explanations are difficult to test. However, the effects of emotional or sexual abuse can well be believed when we find that 'serial killers' such as
Frederick and Rosemary West suffered terribly as children (Wansell 1996). Out of 36 sex murderers interviewed in the USA 42% were found to have been
sexually abused as youngsters (Ressler et al 1988). Dietz and Warren (1995) found that 76% of the 41 serial rapists that they interviewed were abused when
young. Having said this though only about 10% of abused children go on to commit crimes.
Psychoanalytic theory would predict that 'over-controlled' individuals could save up all their emotional turmoil and then explode into a torrent of violence!
However, one of the essential assumptions of psychoanalytic theory is that females will have a less developed superego/conscience and will therefore commit more
crime and this is simply not borne out by criminal statistics.
Social Learning Theories






Learning theory would explain criminal behaviour in terms of rewards (reinforcements) and punishment. Such an explanation does not take account of the
individual’s cognitive reasoning. Trasler (1978) suggests that ineffective parental strategies or, in some individual cases, an inability to acquire conditioned fear
responses may produce inadequately socialised children who then go on to offend.
The view that criminal behaviour, in common with all other behaviour, is learned was most clearly expressed by Sutherland (1939) in his theory of ‘differential
association’, which states that:
 criminal behaviour is learned;
 the learning is through association with other people;
 the main part of the learning takes place within close personal groups;
 the learning includes techniques to carry out certain crimes and also specific attitudes and motives conducive towards committing crime;
 the learning experiences — differential associations — will vary in frequency and importance for each individual;
 the process of learning criminal behaviour is no different from the learning of any other behaviour.
Sutherland also attempted an analysis of the gender differential in crime, arguing that boys are more likely to become delinquent than girls because they are less
strictly controlled and are taught to be aggressive and active risk seekers, all characteristics likely to bring success in the criminal world and, indeed, in the
world generally.
Subsequent developments of Sutherland’s theory emphasise the role of rewards and punishments, whilst the acceptance of social learning theory allows for the
consideration of learning by imitation or observation of others’ behaviour and the importance of the social environment (Bandura and Walters, 1963). Peers who
are held in high regard are very influential role models (Bandura, 1977), as are media stars, whilst rewards that might maintain certain behaviours take the
form of status, self-esteem, financial incentives or just plain excitement. Akers (1990) goes even further, whilst sticking with Sutherland’s original theory, and
looks to the meanings of crim-inal behaviour for offenders, thereby adding a useful cognitive dimension. Thus offenders may take on beliefs about offences, which
allow them to maintain their behaviour. These beliefs may be positive, so car thieves might argue that joy riding is good fun and is the only way for them to
access cars, whilst other beliefs allow the negative consequences of some offences to be ‘neutralised’. Other offences are described as not having ‘real’ victims,
e.g. shops, or as so trivial they don’t really count.
Jeffery (1965) stated that such individuals would need to feel reinforced and not punished for associating with certain others. This could explain why some people
from a particular background become criminal and others do not.
Bandura's Social learning theory, instead of looking at how the past affects behaviour says instead that violent behaviour is modelled from others. This occurs
mainly through media such as films and television. Social learning theory is an extension of operant principles. While operant theory maintains that behaviour
is acquired through reinforcement and punishment from the environment, social learning theory holds that behaviour can also be learned at the cognitive level
through observing the actions of other people. Once learned the behaviour may be reinforced or punished by its consequences like any operant behaviour.
Bandura (1977) suggests that there are three aspects to motivation:
1.
External reinforcement (as in operant theory)
2.
Vicarious reinforcement – the observation of other people being rewarded or punished for their behaviour
3.
Self-reinforcement – gaining internal satisfaction from an activity, which therefore motivates the individual to behave in a similar way in the
future.
Page 5 of 6
AQA B A2 PSYCHOLOGY: FORENSIC: Explanations of Criminal Behaviour


Models who are regarded as successful or of a high status are more effective in motivating an individual to copy their behaviour. Observational learning is
thought to take place primarily in three contexts:
1.
In the family
2.
in the prevalent sub culture
3.
Through cultural symbols such as television and books (Bandura 1976).
Learning theory and social learning theories of crime evaluation
For
 The theories are based on carefully conducted empirical research
 They can help to explain why criminality does, to an extent run in families.
 Males and females are socialised very differently, with females encouraged not be aggressive and to conform, males are encouraged to “stick up for
themselves” and be independent.
Against
 The studies on which these theories are based are conducted in laboratories or other artificial environments in carefully controlled conditions. They
therefore lack validity in that they may not be sampling behaviour as it occurs in real life situations.
 The fact that criminal behaviour tends to run in families is not necessarily due to imitation but may be due to circumstances such as social deprivation, or
to genetic propensity to behave in an anti-social way.
 There are biological differences between men and women, especially hormonal ones, and this, rather than socialisation, may account for differential rates of
crime between men and women.
Nature Versus Nurture
Plomin (1990,1994) has convincingly argued that genetics alone cannot explain adult behaviour and focuses much more on the way genes interact with the
environment. He further suggests that the environment cannot be taken as a constant and that the ‘non-shared environment' is a crucial factor in determining adult
outcomes for children in the same family i.e. what most affects children are the things they do not share with their siblings, their own unique individual experiences.
Parents tend to think they raise their children in the same way but families alter over time, sometimes quite significantly, e.g. chronic illness, unemployment, high
mobility, divorce, etc., and children’s experiences vary too, e.g. having an influential teacher, developing a new interest, losing a friend, etc. Plomin suggests that it is
these differences and the way they interact with genetic make-up, which produce personality differences.
Page 6 of 6