Most people when they talk about criminal behaviour have a psychological perspective,
criminals made the choice to commit a crime and should serve the time, offenders just
didn’t didn’t learn the difference from right and wrong when growing up. And harsh sentences
will act as a deterrent for the worst crimes. But there is a very different explanation for
criminal behaviour that these arguments don’t match, what if people are born criminals?
We are going start this discussion on biological explanations with Lombroso’s
idea of the atavistic form. He published his ideas in “the criminal man” in 1876.
Now before I even start, his theory is going to sound really problematic,
and it is. But take a moment to consider that before a scientific approach to
explain criminal behaviour, historically people would use a religious explanation,
suggesting that people who committed crimes were possessed by demons or corrupted by the devil.
So, while you’re going to disagree with Lombroso’s theory you will probably
agree it’s at least a step towards a more scientific understanding of criminality.
So, what is the atavistic form? well ătăvus is a Latin word for ancestor,
and taking an evolutionary perspective, Lombroso suggests that criminals are
people from an earlier stage of development, so are “genetic throwbacks” to an earlier,
more primitive stage of human evolution. This is compared to modern humans who
according to Lombroso, are the non-criminals. This means that criminals are born criminal,
criminality is innate. And importantly Lombroso argued that we can identify these criminals,
they are less evolved, so physically, and mentally different than non-criminals,
they should look and behave similar to our genetic ancestors, this is called degeneration.
Some of the physical differences are an A-symmetrical face, a heavy brow,
ether very small or big ears that stick out from the head, large jaws and excessively long arms.
Lombroso even suggested different types of criminals had different physical features,
for example an upturned nose in thieves and a beak like nose in murderers.
Lombroso’s work founded what is known as the positivist school of criminology.
This suggests that criminal behaviour has a set of distinct characteristics.
Using careful measurements of criminals and non-criminals, positivist criminologists find
evidence for the causes of criminal behaviour. So as Lombroso argued for biological differences,
he backed up his ideas with biological measurements.
Over the years Lombroso and his students measured the bodies of over four thousand living and dead
criminals mainly focusing on the skull. Evaluations of atavistic form.
Now when evaluating Lombroso’s theory of the atavistic form
we can start with the research he conducted. While he studied the bodies of thousands of criminals,
He didn’t compare these results with a control group of non-criminals. This suggests that the
features observed by Lombroso could have been common in non-criminals at the time and may have
been linked to nutrition in the poor or linked to the presence of physical and mental illness.
Later research by Goring did use a control group, comparing a wide range of biological measurements
of over 3000 English non-criminals with over 3000 English criminals and, the results of the study?
"the physical and mental constitution of both criminal and law-abiding persons, of the same age,
stature, class, and intelligence, are identical.
There is no such thing as an anthropological criminal type."
well after that study Lombroso’s atavistic theory lost popularity among scientists.
I do have some positive evaluations, but before talking about any positive legacy
of Lombroso’s work I think we need to talk about the scientific racism of his ideas.
Lombroso explicitly selected features of human anatomy that are common among black people,
his theory then suggests that black people are biologically less evolved and criminal,
these ideas have been used to justify policies that have harmed black communities.
For example, the eugenics movement that attempted to stop groups having children
if they were thought to be genetically unfit, to racist IQ testing in America that was biased
against black people. While these ideas have been rejected by modern psychology and biology it’s
still part of the subject’s legacy, and highlights the importance of carefully considering the
social sensitivity of the research we conduct. Anther similar point, Lombroso’s theory has a
problem with cause and effect, it could be that many of the criminal physical characteristics he
identified actually led to stigma, these people because they were rejected by society turned to
crime, ultimately creating a criminal stereotype that ends up working as a self-fulfilling
prophecy. If you look a certain way, you are told you look like a criminal so you act like one.
Okay so what can we say that is a positive of Lombroso’s ideas? Well, his positivist
criminology was the first scientific attempt to define the causes of criminal behaviour,
attempting to confirm theories by using empirical methods, like taking careful measurements. This
was an improvement on theories that suggested criminality was due to sin,
demonic possession or that criminals were just feeble-minded.
One point that could be seen as a positive or negative evaluation is Lombroso rejected free
will, and suggested criminal behaviour was due to biological determinism.
Because this means factors outside of the criminal’s control, this supports an argument for
less severe punishments and a focus on treatment. Before I go on, a final fact about Lombroso,
he requested that after he died his colleges add his body to the research, they examined his
skull and took measurements. and now in his own museum in Turin Italy, his perfectly preserved
head floats in a glass jar alongside hundreds of the skulls he used as evidence for his theory.
I’m not going to show you a picture of that, but if your interested you can google it.
Biological explanations of offending behaviour – Genetic and neural explanations
Atavistic theories have been completed rejected,
and many theories after focused on social explanations
But idea that criminals are born, so criminal behaviour is innate never really went away,
and is now an active area of research. Now while Genetic and Neural explanations
are linked, and I’m going to talk about the connections between them, keep in mind you can
be asked about them individually and that should shape your response to the question your asked.
So, what are the arguments that criminality is genetic,
well in any discussion of genes and behaviour we should make the distinction between the
presence of a gene in the genetic code, or the genotype, and the expression of that gene,
so the actual behaviour that genotype codes for, the phenotype. So, this explanation
suggests that violent criminals inherit a gene or set of genes that lead to violent crime.
One indication is to look at family studies, twin studies and adoption studies
to see if criminal violence is more common between genetically close family members,
especially if shared environment is controlled for. And that is what we see.
However, while that indicates a genetic origin, it can’t tell us which genes are responsible.
Candidate genes have been suggested, one example is the short variant M-A-O-A genotype. This gene
regulates the production of the M-A-O-A enzyme, it works by breaking down neurotransmitters
like serotonin, dopamine and noradrenaline. This short version produces fewer enzymes,
disrupting the brains ability to regulate those neurotransmitters. I will tell you in a few
minutes what these neurotransmitters do in more detail. But this genetic
variant is linked to poorer impulse control. Now about one in three males worldwide have
the short variant M-A-O-A gene, and they are not all violent criminals. So the argument is
genetic factors only produce aggressive behaviour in combination with environmental factors.
One argument is diathesis stress, the presence of a gene is a vulnerability, the diathesis.
But later negative life events, called stressors are needed to trigger the violent behaviour.
Before I talk about neurological factors, I want to tell you about a meta-analysis.
Rhee combined the participants of 51 adoption and twin studies,
including over 110 thousand participants. All of these studies looked at anti-social behaviour.
From this data Rhee was able to calculate the relative contribution of genetic and
environmental factors on anti-social behaviour. Genetics accounted for 41% of the variance
and environmental factors 59%. Now you may look at this and say,
well it looks like the environment is more important than genetics, and that may be true,
but genetic theories of violent crime and not accepted at all by many theorists.
So this is strong evidence that genetic factors really do play a large determining role in if
someone displays anti-social behaviour, with huge implications that I will cover in the evaluations.
The neural explanation suggests that there are a range of biological processes in the brain that
lead to criminal behaviour. Now of course many of these processes are likely due to genetic factors.
If we consider neuro transmitters first, so the biological molecules that regulate
brain activity at the synapse, there are a few that are linked to offending.
Noradrenaline is a part of the fight or flight response, and higher levels are
linked to violence. Low levels of serotonin are linked to impulsive behaviour and a craving for
dopamine as seen in drug addicts can lead to criminal behaviour to satisfy that craving.
If we look at large neural structures in the brain there are two locations
that seem to be linked to violence, the limbic system and the frontal cortex.
Emotions like guilt, empathy and compassion are processed in the limbic system,
low activity here is associated with psychopathic behaviour, people able to
commit violence without the feeling any of the emotions that would usually stop that behaviour.
The frontal cortex is the place where your decision making happens,
also called executive function. If this area is smaller and less active
then its less able to override and stop strong negative emotions and impulses
resulting in violent behaviour. # Research Evaluations
So what evidence is there for genes and neurological factors?
Well our understanding of the MOAO gene started with a researcher called
Brunner (1993) he investigated the case of a family from the Netherlands.
The men of this family were exceptionally violent. Brunner discovered the males in
this family had a faulty version of the MOAO gene, it produced virtually no enzyme.
This suggested that criminal aggression could have a genetic origin,
that results in a neurological change, ultimately resulting in violent criminality.
The next two studies just consider neural structures.
Firstly Raine found that the prefrontal grey matter volume in people with anti-social
personality disorder was 11% less than a control group. This data suggests there is a link between
a neurological difference, and the reduction in conscience in people with APD.
And a final study by Kiehl is an FMRI study of criminal psychopaths,
non-psychopathic criminals and a control group of non-criminals.
Only the criminal psychopaths showed a reduction in activity in the limbic system, suggesting they
don’t experience the strong emotions that most people feel that inhibit violence.
# General Evaluations – Biological explanations of offending behaviour
If we take a biological approach to criminal behaviour, this has important implications.
Genetic and neural factors are completely out of the control of the individual.
Criminal justice, could view people who are biologically predisposed to violence
as needing treatment rather then punishment. There are strong views on both sides of this,
but it is possible treatment could lead to a safer society, as punishment is unlikely to be effective
against people with biological vulnerabilities. However, researchers in this area need to be
careful about the socially sensitive nature of their research. Genetic theories around violence
could lead to policies that are discriminatory of groups of people with certain genotypes,
and justify that discrimination the basis of reducing violent crime.
Any attempt at explaining violent crime as purely biological would of course be biologically
reductionist, a more holistic approach would include factors such as drug use, mental illness
and child development. Also, a consideration of how these factors interact would be closer to
a valid understanding of criminal violence. Much of the research linking genes to crime
has focused on violent crime, and many criminals are non-violent.
One final point is about the validity of many of the studies. It can be difficult
to obtain large samples of violent criminals for studies. Especially those that happen to be
twins or adopted. So many of the studies measure anti-social behaviour at a non-criminal level.
It could be argued this is very different to violent offending.
Here are some real exam questions you can try out. Patrons can see a walk though video
of these over on my website. For everyone else make sure your subscribed,
and see you in the next video, biological explanations of offender