To what Extent can Biological Factors explain Criminal Behaviour? The Case of Psychopathy

Published: 2023/07/06 Number of words: 1344

Criminal behaviours have been consistently linked to biological factors by many criminologists and this consistent association between the two variables has meant that in many parts of the world, biological evidence is used to deal with certain criminal cases in courts where the influence of the biology is suspected to have influenced the suspects (Denno, 2015). However, it is widely accepted by many experts in the field that biological factors are not responsible for all types of crimes, rather social factors equally contribute their own part (Ayar et al., 2012). While this is acknowledged, the influences of biology seem significant, particularly with respect to violent crimes as will be demonstrated in the main body of this essay. This essay will focus on the contributions of biological factors on criminal behaviour with psychopathy as a case example. It will draw on research evidence to demonstrate the extent to which the biological factors are capable of contributing to criminal behaviour, such as the high rate of recidivism in psychopaths. The essay will highlight the limitations of biological factors in understanding the criminal behaviours of psychopaths.

Psychopathy stands as one of the personality disorders strongly linked to criminal violence, which is also widely used as an example to illustrate the connection between biology and crime (Gonzalez et al., 2019). A psychopath is defined as ‘a self-centered, callous, and remorseless profoundly lacking in empathy and the ability to form warm emotional relationships with others, a person who functions without the restraints of conscience’ (Hare, 1993, p.2). Psychopathy has been found to be among the strongest predictors of violence and aggression (Reidy et al., 2015). Psychopaths commit violent offences in its most severe forms, and they also commit many violent crimes twice the rate committed by non-psychopathic offenders while the violent recidivism rate for psychopaths is no less than five times higher than the recidivism rate for non-psychopaths (Reidy et al., 2015).

The definition of a psychopath above can explain their high involvements in criminal violence and recidivism. Firstly, they lack empathy, and this could make them to offend people without trying to put their victims in their shoes. Secondly, psychopaths are remorseless. A sense of remorse can make an offender to change his ways having considered his previous offences as bad. With psychopaths lacking in remorse, it is not surprising to see that they score high in recidivism, particularly violent one. Psychopaths have equally been found to suffer from emotional dysfunction (Francisco, 2006). Again, this emotional deficit could also contribute to an inability to connect with their victims’ situations. The emotional dysfunction in psychopaths has been found to contribute to their engagement in sexual sadism in particular (Kirch & Becker, 2007).

An important point to note here is that the behaviours of psychopaths have neurobiological basis. For example, Nummenmaa et al. (2021) recently tested the neural basis of this trait on over 100 psychopaths, including both convicted and non-convicted ones using T1-weighted magnetic resonance imaging and found that psychopathic offenders had lower density of grey matter in their anterior insula and orbitofrontal cortex while affective psychopathy traits in the community sample similarly showed lower density of grey matter in the same aforementioned brain regions. This is a strong source of evidence indicating that psychopathy has biological basis and that it does not matter whether the psychopath has committed a crime or not. Nummenmaa et al.’s (2021) study supports previous ones that have implicated different brain regions in psychopathy. Blair (2003, p.5), for instance, had previously delved into the contributions of the amygdala, noting that the ‘amygdala is thus involved in all the processes that, when impaired, give rise to the functional impairments shown by individuals with psychopathy’.

Evidence of genetic factors in criminality is drawn from different sources. For example, Fuss (2016) observed that a number of clinically established techniques ranging from neurogenetics to structural brain imaging, electroencephalogram (EEG), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have been used to demonstrate the role of biology in certain criminal cases in courtrooms. Nummenmaa et al.’s (2021) study has shown that this same process equally applies to psychopathy, that is, the fact that the above techniques are able to establish the neural basis for their pathology just like the case with other traits or disorders linked to criminality. Importantly, Gonzalez et al. (2021) have shown that these techniques are also used when dealing with criminal cases involving psychopaths in courts.

Although biological factors are linked to psychopathy and the criminal violence they commit, it is important to note that this does not necessarily mean that they were born with these traits. The ‘nature’ and ‘nurture’ debate in psychology and criminology applies to psychopathy just as it applies to other traits. While some researchers on this draw on genetic histories of the psychopaths (e.g., Blair, 2003; Nummenmaa et al., 2021), others draw on the impacts of social factors (e.g., Hickey, 2013; Scott, 2003). It is argued that extreme forms of abuse and severe neglect during childhood can lead to someone displaying the behavioural characteristics that are seen in psychopaths (Scott, 2003). Thus, the actual source of this trait remains open to debate. While this remains debatable, what has been empirically found to be true is that these psychopaths have neural basis to their behaviours.

In conclusion, this essay has explored the contributions of biological factors on criminal behaviour. Psychopathy is used as an example of a biological trait linked to crime to illustrate the link between biology and crime. The research evidence analysed above show that criminal behaviour has neurobiological basis, and this is particularly the case with psychopathic offenders. Different parts of the brain have been implicated in this process. However, not all psychopaths with brain impairments have been convicted of crime or have committed a crime. This indicate that while biological factors play a role, they do not appear to be primary factors since some of the psychopaths with the same brain deficiency with all other psychopaths are law abiding. This suggests that while biological factors play their part, social factors should not be overlooked.


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