APPLIED CRIMINAL PSYCHOLOGY

BIOLOGICAL BASES OF CRIMINAL BEHAVIOUR

V.M. Westerberg

Massey University

School of Psychology

NEW ZEALAND

TOPICS

In this presentation we will discuss:

The Theory of Evolution on crimeGenetic basis of criminal behaviourAnatomical and functional bases of criminal behaviourTemperamentTwin, adoptees, and family studiesVideoConclusions

The Roots of Criminal Behaviour:EVOLUTION

Criminal behaviour, from physical aggression to theft, is a universal animal trait having to

do with survival and explained by Evolutionary Theory [Darwin, Lorenz, Bowlby] (Lerner,

Jacobs, & Wertlieb,2005).

How does Genetics work?

Behavioural Genetic Understanding of Criminal Conduct

At the heart of biology is the estimation of genetic and environmental influences.

The environment cannot provide an individual with a trait the s/he does not have, it can only modify existing ones.

Genetics are expressed not only on the outside

...but also on the inside

TEMPERAMENT

Temperament refers to stable innate characteristics that are the precursors of personality.

The ‘difficult’ child: intense reactions, negative mood, slow adaption and irregular functions.

Some psychopathological conditions can be traced back to childhood or adolescence, like sociopathic behaviour. Addressing them in time is essential to try to prevent escalation of the traits into adulthood.

TWIN STUDIES

TWINS 13 published analyses on the genetics of adult crimes using twins have

been collected. All of them showed greater concordance in MZ twins (51.5%) vs. DZ

twins (20.6%).

TWINS REARED APART A study done with 32 sets of monozygotic twins reared apart since

shortly after birth (median age at separation was 0.2 years) were interviewed separately and blindly using DSM-III Axis I for psychiatric disorders and antisocial personality (Grove et al., 1990). The resulst showed significant commonalities in the genetic factors responsible for the traits of alcohol-related problems, drug-related problems, childhood antisocial behaviour, and adult antisocial behaviour..

Christiansen (1977) studied 8 cases of MZ twins with one of the pair having a criminal record. He noted that sociopathic traits was found in 4 of the siblings without a police record.

ADOPTION STUDIES

Provide powerful support for findings found in twin studies

Variation on adoption studies is the ‘cross fostering paradigm’.

Are biological parents criminal

Yes No

Are adoptive parents criminal

Yes 24.5% 14.7%

No 20% 13.5%

CRIMINAL FAMILIES

Consistent with the Cambridge Study and the Pittsburgh Youth Study, the results from a recent Tasmanian study (Dax, 2011) suggests that the children of parents with a criminal record have a much greater likelihood of becoming involved in crime themselves than the children of parents who do not have a criminal record.

A child born into a family where neither parent has a criminal record had a very high probability (between 76% and 80% for sons & daughters resp.) of not having a criminal record (Dax, 2011)

However, a child born into a family where both parents had a criminal record had a fairly low probability of not having a criminal record (27.5% for sons; 41.1% for daughters) and the child was more likely to obtain a criminal record for a serious offence (66.9% for sons; 43.8% for daughters) (Dax, 2011)

Official records are known to substantially underestimate the true level of offending over the life course (Soothill, Fitzpatrick & Francis 2009)

EXPLORING THE CRIMINAL MIND

http://www.youtube.com/watch?v=u2V0vOFexY4

ANATOMY OF CRIMINAL BEHAVIOUR

The amygdala is the seat of emotions and emotional memory– which is of particular interest to the study of criminal behavior.

Executive functions reside in the prefrontal and orbito-frontal cortices which explain the lack of self-control, inability to follow a life plan and lack of empathy. Because the amygdala and the cortex are responsible for brain-related behaviours, it follows that functional and/or anatomical abnormalities in these areas will have predictable consequences.

TO SUMMARIZE

In this presentation we have shown that :

Genetic influences on criminality are complex and multifaceted. Anatomical and functional studies show the relationship.

Evolutionary theory accounts for the natural reasons of criminal behaviour.

Crime runs in families where parents and/or siblings of a given offender have a history of serious criminal offending.

Twin and adoptees studies demonstrate biology has a causal effect on criminality moderated to a small degree by environmental factors.

Evidence points to the need for early identification and

intervention with high-risk children.

IN CONCLUSION...

Just as with many other medical and psychological conditions, having the genetic tendency for a disorder does not mean that the individual will invariably develop it.

In the case of criminal conduct, biology loads the gun, the environment takes aim, and the personality pulls the trigger.