The Importance of Genes in Understanding Criminal Behaviour

There are many schools of thought as to what causes a criminal to exhibit criminal behavior, but for the benefit of this essay the focus is going to be limited to the effects of genes on the understanding of criminal behaviour. However, it is important to bare in mind that not any one discipline can explain fully the causality of criminality and a multidisciplinary approach would offer more of an insight.

Early biological research into criminality is scathed with criticism, ethical issues and political manipulation and many criminologists choose not to include biological explanations for criminal behavior. Instead, many focus on environmental and sociological explanations (marsh et al, 2006). However, biology does have a part to play in human development, mental disorders, mental illnesses and personality traits, all of which can increase the likelihood of a person exhibiting criminal behavior.

Academics such as Lombroso, a significant figure in early modern criminology, were of an opinion that physiological features of a person offered an insight to criminality (Jones, 2005). Lombroso used Charles Darwin’s theory of evolution to argue that criminal behaviour was atavistic and therefore criminals were biologically less evolved, causing physiological differences between criminals and non criminals (Marsh et al, 2006). He categorised criminals on physiological features such as having a low and narrow forehead, larger jaws, bigger ears and longer arms, ect (Jones, 2005).

Much of Lombroso’s work is heavily criticised for being unscientific, simplistic and false (marsh et al, 2006). Lombroso later adapted his theory to include social and environmental reasoning to criminality. (FIND REF)

Although the work of Lombroso on physiological features and criminality is heavily flawed, studies such as Glueck & Glueck, 1950 have found a correlation between physiological characteristics and delinquents. Glueck & Glueck, 1950 stated that 60% of delinquents had a mesomorphic body shape, unlike non delinquents of which they found had only a 30% make up of mesomorphs (Marsh et al, 2006). This study clearly demonstrates a correlation between body shape and criminality, yet the study fails to provide a direct causal link.

However, if explored further, the body shape Glueck & Glueck linked with criminal behaviour is closely linked to levels of testosterone (marsh et al, 2006). Testosterone is negatively correlated with empathy and a person demonstrating low levels of empathy will have an increased risk of exhibiting criminal behaviour (Marsh et al, 2006).

An Impulsive personality is widely associated with criminal behaviour (Fairbanks et al, 2004). Impulsivity is also a common trait associated with disorders such as ADHD, conduct disorder, bipolar disorder and some personality disorders (Moeller et al 2001, cited in, Fairbanks et al, 2004). Impulsivity lowers inhibition, reduces information processing (Passamonti et al, 2006), all of which can increase the chances of criminality. Impulsivity is also an important feature in aggressive behaviour (Kockler & Stanford, 2007).

A variety of studies have shown that the enzyme monoamine oxidase can affect the level of a person’s impulsiveness (Passamonti et