Criminal Behaviour

Lecture Topic 2

Week 2

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Lecture Objectives

At the end of this lecture you should be able to:Describe biological factorsEvaluate critically the evidence for a

biological basis to crimeDescribe and critique Lombroso’s &

Sheldon’s theoriesDescribe and critique Eysenck’s theory of

criminality

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Biological factors include: Genetic disposition or predisposition Acquired deficits (birth trauma, other

head injuries) and poisons causing permanent damage (heavy metal poisoning)

Transient biochemical problems (drugs, hormone imbalances)

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Physique

Physique was thought to be the outward sign of a criminal disposition. Includes the theories of:

Lombroso’s Atavistic or Born Criminal Phrenology Sheldon’s Somatotyping

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Darwinian influence

Remember that many of the early biological theories were developed shortly after the publication of Darwin’s Origin of Species

Early theories were simplistic and relied heavily upon the notion of evolution (quite a naïve notion at that)

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Lombroso’s Born Criminal Instrumental in establishing asylums for

the criminally insane In November 1872, Lombroso

performed an autopsy on the body of a criminal by the name of Villella

Villella’s skull revealed an anomaly in the cranial structure, a smooth concavity in the occipital area described as the median occipital fossette

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The discovery of the fossette convinced Lombroso that criminals are born

Lombroso considered the ‘criminal’ as a separate species, which had not sufficiently evolved

Lombroso termed this ‘evolutionarily retarded species’ Homo delinquens

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Physical Description

Homo delinquens had: Asymmetrical skulls Flattened noses Large ears Fat lips Enormous jaws High cheekbones Mongolian eye characteristics

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They also had: An affinity for tattoos Cruel games Orgies A peculiar primitive slang

Lombroso concluded that these people could not adapt socially and morally to the demands of the modern times.

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“…the desire not only to extinguish life in the victim, but to mutilate the corpse, tear its flesh and drink its blood.”

(Lombroso’s speech at the Sixth Congress of Criminal Anthropology)

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Softening of Lombroso’s Theory Over time Lombroso softened his

approach, and acknowledge that only around 1/3 of criminals fell into the ‘atavistic’ category

For the remainder the environment was the key factor

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Lombroso’s Criminal Types Born Criminal – innately antisocial Habitual or professional Criminal –

systematic violation of law, crime as a profession

Judicial Criminal – violated law through a lack of prudence or forethought (impulsive)

Criminals of Passion – violated law through honour, love, noble ambition, patriotism

Criminaloids – violated law as a result of a weak character (easily lead astray)

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Lombroso also acknowledged the morally insane and the hysterical criminal

Female offenders were originally considered by Lombroso to “lack a mother sense”, but later he described them as…More terrible and cruel than any man,

almost monsterlike – “vengeances of a refined cruelty”

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Phrenology

Phrenology was based on two basic premises:Firstly, that the brain was the organ of the

mind and that size matteredSecondly, that the size of different areas of

the brain would be related to the shape of the skull

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Very influential at the time – the wealthy would go and get their bumps read!

Probably influenced Lombroso

So let’s play with my Phrenology Head!

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William Sheldon

Theory of Somatotyping (relationship between body type and personality)

Still used today – i.e., chiropractic, eating disorders

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Classify yourself

For each of the following descriptions, give yourself a score out of 7, with 1 being not at all like me to 7 being exactly like me

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soft body underdeveloped muscles round shaped over-developed digestive system

Score from 1 (not at all like me) to

7 (exactly like me)

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hard, muscular body overly mature appearance rectangular shaped thick skin upright posture

Score from 1 (not at all like me) to

7 (exactly like me)

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thin flat chest delicate build young appearance tall lightly muscled stoop-shouldered large brain

Score from 1 (not at all like me) to

7 (exactly like me)

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You should now have 3 scores If your first score is highest then you are

endomorphic If your second score is highest then you

are mesomorphic If your third score is highest then you

are ectomorphic

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Let’s Group

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Endomorphs Endomorphs HereHere

Mesomorphs Mesomorphs HereHere

Ectomorphs Ectomorphs HereHere

Ectomorphic self-conscious preference for privacy introverted inhibited socially anxious artistic mentally intense emotionally restrained

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Mesomorphic adventurous desire for power and dominance courageous indifference to what others think or want assertive, bold zest for physical activity competitive love of risk and chance

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Endomorphic love of food tolerant evenness of emotions love of comfort sociable good humored relaxed need for affection

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Sheldon avoided sharp distinctions between body types – must have a 7 to be classified, and most are somewhere in between

Achieving a 7 was unusual Most people will have a primary body type,

for example 3-2-5 would be primarily ectomorphic but would contain characteristics of other body types

Average would be 4-4-4

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The basic problem

Is your personality driven by your body type?

Or is your body type driven by your personality?

Sheldon attempted to overcome this problem by basing body type on objective measures of shoulder width versus hip width

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The findings…

University males typically 4-4-4 Delinquents tended to be mesomorphic Some endomorphic delinquents Very few ectomorphic delinquents

Modern findings refute Sheldon’s somatotyping and its relationship with criminality

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Physiological Indices

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Heart Rate & Criminality Lower heart rate has been found

amongst criminals, delinquents and the children of criminals compared to controls. Findings consistent across a range of studies (Venables,1988). Decorated bomb disposal operators have lower heart rate than non-decorated bomb disposal operators which was lower than soldier controls.

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Implications: heart rate is related to fearlessness, criminals have a lower level of fearlessness than non-criminals. This could be either learnt or biological although Venables suggests that it is hereditary. The finding regarding children is interesting to note though.

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EEG Patterns and Criminality Some evidence suggests criminals have

different electroencephalogram (EEG) readings notably slower alpha rhythms and slower activity generally than non-criminals. Whatever the explanations (and there are some tentative ones) this difference has been found and does suggest a genetic difference.

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Hypoglycaemia and Criminality Hypoglycaemia has been linked to

irritability, outbursts and aggression. Differences in hypoglycaemia and related conditions (insulin secretions) found between aggressive criminals and controls. But hypoglycaemia and alcohol significance, since alcohol impacts on insulin secretion. The physiological explanations are unclear.

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Hyperactivity

Strong relationship between ADHD and criminality

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Hemisphere Functioning and Criminality

Some evidence for hemispheric dysfunction among certain offenders, specifically violent and aggressive offenders. Research is based on WAIS score imbalances between the Verbal and Performance scores. Performance is considered to be sourced in the right hemisphere and verbal in the left.

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The differences however could be due to environmental differences in learning. That is, Verbal scores are more strongly related to academic performance than performance scores.

Physiological measures suggest that violent subjects have a lower left hemisphere arousal

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Attractiveness

Has been suggested that facial and general physical attractiveness is lower in criminals

Social ramifications of attractiveness most likely explanation

Offenders who undergo cosmetic surgery tend to have a lower recidivism rate!

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Minor Physical Abnormalities MPA’s are slightly correlated with abnormal

behaviour, including violence. MPA’s develop during 1st trimester.

Suggested that brain abnormalities also occur at this time.

Studies show MPA’s are predictive of violent behaviour in those children who have poor parenting. Strong suggestions of an interaction effect. Not a genetic indicator.

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Neurotransmitters Studies suggest reduced serotonin in antisocial

and aggressive persons with no effect for other neurotransmitters.

Impact on suicide also an issue. Results of studies to date suggest the need to

control for specific influences such as alcoholism and nutrition.

Overall, there is now very strong evidence for neuro-transmitter implications in violence.

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Brain Dysfunction

Some brain dysfunction linked to anti-social and violent behaviour. This is strongest for violent offences and frontal lobe dysfunction; and temporal lobe deficits for sex offenders.

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Prefrontal cortex is responsible for executive functions and executive control – sustained attention, working memory, abstract decision making, self regulation and inhibition, planning and organising. Clearly, a poor functioning prefrontal cortex can result in poor impulse control.

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Brain Dysfunction

Studies are based on neuropsychological tests and brain imaging

Conclusion: Could be acquired deficits but may also be genetic.

Acquired brain damage is related to violent offending.

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Research Design

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Twin StudiesTwin Studies Adoption Adoption StudiesStudies

Control Control VariableVariable

EnvironmentEnvironment GeneticsGenetics

Experimental Experimental VariableVariable

GeneticsGenetics EnvironmentEnvironment

Note: It is ethically impossible to randomly assign Note: It is ethically impossible to randomly assign infants!infants!

Twin Studies

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MonozygoticMonozygotic

Genetically IdenticalGenetically Identical

DizygoticDizygotic

Genetically DifferentGenetically Different

Twin Studies

Aim is to tease out genetic and environmental effects.

Assumption: monozygotic and dizygotic twins have some environment but different genes.

Concordance rates: probability of one twin being criminal if the other is also. Average concordance rate for MZ is 51.5% and for DZ 20.6%. For most recent studies 31% v 12.9%.

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Twin Studies

Although some limitations, these tend to introduce random error or a bias which would reduce the effect.

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Adoption studies

Use of cross fostering paradigm. Compares criminality in children who have been adopted into non-familial families.

Results shown in 2x2 design

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Adoption studies

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   Biological Biological Parent Parent CriminalCriminal

Biological Biological Parent Non-Parent Non-CriminalCriminal

Adopted Adopted Parent Parent CriminalCriminal

24.5%24.5% 14.7%14.7%

Adopted Adopted Parent Non-Parent Non-CriminalCriminal

20%20% 13.5%13.5%

Conclusion

The evidence is consistently pointing a biological basis for offending behaviours, especially violent crime.

The biological basis could be genetic or acquired or an interaction effect.

The evidence strongly supports a genetic pre-disposition to crime.

The evidence also points to a very strong interaction effect.

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Eysenck’s Theory

An elaborate and complex theory of criminal behaviour. Eysenck has combined learning theory with psychophysiology to produce a theory that tries to explain criminal behaviour.

He suggests that there are four main personality dimensions:

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Eysenck’s Theory

intelligence - related to the cerebral cortex as a whole

extraversion/intraversion - related to the reticular activating system

neuroticism - related to the autonomic nervous system

And…

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Eysenck’s Theory

psychoticism - as yet no specific brain location – similar to psychopathy – possible neurological basis

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Eysenck’s Theory

Eysenck's notion of intelligence is consistent with the G factor theories.

 

Extraversion refers to behaviours such as sociability, impulsivity, high needs for excitement and generally high needs for excitement.

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Extroversion Intraversion refers to the need for quiet, for close

friends, for control. Extraverts postulated to have overactive RAS -

filters out too much of the incoming information. Consequently, they need high excitation to achieve homoeostatic functioning. Results in excitation seeking behaviours & thus criminal behaviour.

Intraverts - under active RAS - lets in too much information or amplifies the information. Consequently, stimulation avoidance since homeostasis of cortical arousal is readily achieved.

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NeuroticismNeuroticism is related to the autonomic nervous system - this system prepares the body for fight/flight response.High neuroticism – over-active ANS – turns on quickly or stays on longer. ANS over arousal leads to greater impact of stressful and anxiety producing events. To avoid the activation of the ANS they tend to act in habitual behaviours. If a person has learnt antisocial behaviours as a way of reducing the impact of the autonomic nervous system then they are more likely to engage in continuous antisocial acts.

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Psychoticism

Most poorly articulated concept in Eysenck's theory. It is very similar to psychopathy, cold callous indifferent to the needs of others - the opposite of altruism.

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Criminal BehaviourThese personality predispositions interact with one's learning history.

Eysenck suggests that conditioned fear is a critical component of not committing crime. That is, we do not act in antisocial ways because these are conditioned stimuli for conditioned fear (or anxiety). The unconditioned stimulus is the aversive consequence (the beatings) and the unconditioned behaviour is the antisocial act.

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Criminal Behaviour

ie antisocial act leads aversive consequence leads to fear/anxiety after several trialsantisocial act leads fear/anxiety However, for extraverts the learning process is much more difficult because the RAS stops the information from being properly synthesised.

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Criminal Behaviour

Neuroticism result in higher levels of habitual behaviour. Thus if a extravert has not been properly conditioned it is likely that they will engage in repetitive antisocial acts.

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The Evidence

High excitation seeking is related to criminal behaviour.Family violence perpetrators have overactive ANS.Violent offenders have higher levels of attribution of hostile intent.But studies using questionnaires (especially those designed by Eysenck to measure these attributes) have not been very supportive.

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The Evidence

The flaws therefore, could be anywhere in the model, from measurement problems to the whole thing being wrong. Furthermore, the theory does suffer from the problem of being a general explanation for crime.

The theory may be useful for explaining why some people commit crime but not explain all criminal behaviour.

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The Evidence

One of the most serious problems is the reliance on classical conditioning. There is no doubt that most human behaviour is not learnt through classical conditioning. The theory undoubtedly needs to take into account other forms of learning.

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Consolidation

Write down three things you remember about these sections of the lecture

Early theories (Lombroso & Sheldon) Twin & Adoption Studies Personality & RAS

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