6. Biological Influences on Criminal Behaviour
A healthy diet, with essential nutrients, vitamins, and minerals, is vital for brain development, and an inadequate diet in childhood can result in neural deficits leading to antisocial behaviour, including aggression and reduced self-control (Jackson, 2016), and to many health issues. As many neurotransmitter precursors come from diet, a poor-quality diet may affect neural function simply by a lack of precursors.
Low SES is a known risk factor for antisocial behaviour, as it includes many overall risk factors such as poverty, reduced education and job opportunities, together with the discrimination that often follows. Poverty in general reduces a developing child’s access to nutritious, fresh food, so the effects of low SES are likely to be exacerbated by a poor diet, with its resultant health issues, and also by its impact on neural development.
Supplementing diet has been understood as a way to improve health and behaviour since Lombroso (Bohannon, 2009), and many large-scale studies on dietary supplementation for malnourished children have shown extraordinary improvements in behaviour (Liu, 2004; Raine et al., 2003). A poor-quality diet does not necessarily mean starvation. A large global study of approximately 200,000 children from forty-one countries showed a 123% increase in bullying behaviour in children eating poor-quality rather than nutritious food (Jackson, 2017). Such information opens the door to intervention strategies that can increase health and reduce antisocial behaviour with supplementation and education. A good example of such an intervention is the Breakfast Club of Canada, which provides children with nutritious breakfasts.
We have seen that direct abuse has both sociological and biological impacts on a child’s well-being and behaviour throughout the life course and even transgenerationally. But institutionalisation and residential schools have other insidious effects. As well as being physically, emotionally and sexually abused, residential school children were underfed, given poor-quality food, and frequently starved, as discussed in Hunger experienced in residential schools linked to present-day health problems. Aside from the obvious torture of such treatment at the time, the effects of poor diet and starvation can have long-lasting impacts on a person’s biology, health, and behaviour. Colonisation and residential schools deprived Indigenous Peoples of their traditional food sources and their knowledge of ways to harvest wild animals and plants to maintain a healthy diet. Once lost, these skills cannot be passed to future generations, leading to increased diet-related health issues. These issues are not just historical but persist today as many Indigenous Peoples have lost pre-colonial connections to the land and suffer ongoing biological consequences (Monchalin, 2016).
Foetal Alcohol Syndrome (FAS) and F0etal Alcohol Spectrum Disorder (FASD)
Some clearly environmental factors that impact behaviour can also have biological effects. It is well known that alcohol usage is involved in a vast number of crimes, as it increases impulsivity and violence and reduces self-control. But alcohol usage during pregnancy can have much more insidious impacts on the developing child, resulting in a wide range of health and behaviour problems. Prenatal alcohol exposure affects the developing brain as well as the serotonergic system, the dopamine system, hormonal systems, the immune system, and other aspects of neural development. These effects can result in children developing cognition, attention, communication, and perceptual deficits; hyperactivity; an inability to understand consequences; and poor peer relationships (CanFASD, 2018).
Alcohol use and abuse, which relates to residential school abuses and other systemic racism and discrimination, has historically disproportionately affected Indigenous Peoples (Johnson, 2016). Although such abuse is usually considered in a sociological context, it also has a biological basis. The effect of alcohol on an individual, such as how intoxicated they become, and how fast they process the alcohol, depends on many features such as whether they had eaten first, the speed at which they consumed the drink, and the alcohol content of the drink, but also the person’s biology. Alcohol is broken down by alcohol dehydrogenase and aldehyde dehydrogenase enzymes, which are controlled by several genes. Different ancestral groups have different alleles for these genes, impacting their alcohol metabolism and thus their ability to tolerate the effects of alcohol (Wall et al., 2016).
Colonialism, intergenerational abuse, and residential schools have greatly increased maladaptive coping mechanisms such as alcohol usage among Indigenous women, resulting in much higher rates (38 times) of FASD than in the general population (Popova et al., 2017). In Canada, youth with FASD are 19–40 times more likely to be incarcerated than non-FASD youth (Malbin, 2004; Popova et al., 2011). This is a vicious circle as incarceration exacerbates the effects of FASD as such people are highly suggestible, form poor peer relationships and are frequently victimised, increasing their recidivism (Brown et al., 2014).