1. Positivist criminology
How did this approach to the study of crime differ from classicist criminology?

2. Positivist criminology – general features (1)
Criminals did not possess free will, but were motivated by factors over which they had no control. We refer to this as determinism.
These factors could be biological, psychological or sociological: here the emphasis is on biological explanations of crime.
Punishment was thus inappropriate – treatment was instead advocated as a response to crime: but this treatment could be of a severe nature.

3. Positivist criminology – general features (2)
The focus of interest was on the offender and not the crime that had been committed.
Theories that sought to explain why an individual committed crime were based on some form of scientific evidence – the ‘search for facts’.
Today we will focus on biological positivism.

4. Biological positivism – origins
This suggests that criminals are born bad (the nurture v. nature debate).
The person who initially put forward this idea was the Italian criminologist, Cesare Lombroso.
His key work in which this idea was put forward was L’Uomo Delinquente, initially published in 1876.

5. Lombroso – key ideas
Criminals were persons who had failed to properly evolve – the concept of atavism.
Criminals could be identified by physical characteristics termed stigmata which reflected their biological imperfections; this idea was developed from phrenology (Joseph Gall) that focused on the shape of a person’s skull.
The rationale of treatment should be to protect society not punish the criminal – and this could result in pre-emptive action.

6. And others suggested a link between physical characteristics and behaviour
In the 1940s, Robert Sheldon popularised the view that the size and shape of a person's body was an indicator of intelligence, moral worth and future achievement.
He put forward three somatotypes – Ectomorphic, Mesomorphic and Endomorphic – which differentiated humans according to distinct physical and psychological traits.

7. Lombroso – criticisms There are two key problems:
The methodology on which Lombroso based his theory was flawed.
The idea that criminals were ‘born bad’ ignored factors external to an individual – a criticism that he took on board in later editions of L’Uomo Delinquente.
This also ignored the existence of free will.
However …

8. Later applications of biological positivism
These suggest that Lombroso was right in pointing to biological imperfections as the source of criminal behaviour but he lacked the scientific means to properly prove this.
More modern scientific methods have led to suggestions that biological imperfections are the root cause of criminal behaviour and also that
These could be inherited – hence crime ‘runs in families’.
More modern applications include …

9. The criminal chromosome
Chromosome deficiencies affect the chemistry of the brain: these were not inherited.
Males with an additional Y Chromosome (hence XYY) were predisposed to violent or anti-social behaviour (Jacobs et al., 1965).
But …
This was not a universal explanation of crime since many persons with such a deficiency did not exhibit criminal behaviour.

10. The criminal gene
Genes reside on chromosomes and there are a large number active in the brain.
Mutated genes are inherited and may result in a person being unable to control his or her emotions.
Han Brunner (1993) suggested that a deficiency of monoamine oxidase A among males in a Dutch family he studied could explain their violent behaviour over many generations.
However, even he refused the idea that this was the criminal gene – although along with other factors it might contribute towards violent or criminal behaviour.

11. Neurophysiological explanations of crime
This approach focuses on brain activity. Key theories associated with it include:
Abnormally low levels of serotonin (a chemical in the brain that regulates mood) can result in violent (often impulsive) behaviour.
Attention Deficit Hyperactivity Disorder (ADHD) – brain dysfunction that causes irrational and often violent behaviour.
Neither of these conditions is inherited.

12. Problems with neurophysiological explanations of crime
The focus on brain disorders as a source of crime ignores all other factors that may contribute to such behaviour.
The emphasis on brain disorders can give rise to an approach that seeks to medicalise a social problem – a cheaper solution than, for example, social reform policies.
This approach may lead to pre-emptive interventions that label those on the receiving end and perhaps result in the behaviour these were seeking to prevent.

13. References / further reading
Brunner, H., Nelen, M., Breakefield, X., Ropers, H. and van Oost, B. (1993) ‘Abnormal Behaviour Associated with a Point Mutation in the Structural Gene for Monoamine Oxidase A’, Science, 262: 578–80.
Jacobs, P., Brunton, M. and Melville, M. (1965) ‘Aggressive Behaviour, Mental Subnormality and the XYY Male’, Nature, 25 December: 1351–2.
Lombroso, C. (1876) L’uomo delinquente. Milan: Hoepl.
Sheldon, W. (1949) Varieties of Delinquent Youth. New York: Harper.
Walklate, S. (2014) Criminology: The Basics, 2 ed. London: Routledge.