Criminology concepts and applications

Criminal Propensity

There is a significant amount of debate about what goes into the making of a criminal. In the past, people have advocated nature or nurture. Modern criminal justice professionals recognize that causation is not a question of nature vs. nurture, but an issue of how nurture (social environment and influences) impacts nature (hereditary influences).

Early Indicators of Adult Criminality

While it is impossible to predict with certainty whether or not someone will grow up to be a criminal, there are certain indicators that are highly predictive of adult criminal behavior. For example, children with behavioral disorders, specifically attention deficit disorder / attention deficit hyperactivity disorder, oppositional defiant disorder, and conduct disorder, are more likely to become criminal offenders when they reach adulthood. Risk-seeking behavior (even non-dangerous risk-seeking behavior) is thought to be linked to low levels of arousal and indicative of later criminality. Furthermore, people with neuropsychological defects may perceive the world as being hostile to them, which increases their likelihood of criminality. In addition, there appears to be a consistency in difficult behavior across a lifetime, so that people who are difficult in an age-inappropriate manner as children are more likely to exhibit criminal behavior as adults. Most significantly, early aggression is linked to adult criminality, perhaps because the consequences of early aggression create a set of circumstances that continuously reinforce violent and aggressive behavior over the course of a lifetime. In addition, factors such as poverty, or maternal substance use or abuse can contribute to adult criminality.

Biological Factors Affecting Adult Propensity

The most significant biological factor affecting adult criminal propensity is also one that is impossible to control. Gender is highly linked to criminal propensity. "Male offenders commit the vast majority of murders, robberies, and burglaries throughout the world. In the United States, approximately 85% of arrests are of male suspects, particularly for the serious violent offenses, such as murder and armed robbery (e.g., see U.S. Department of Justice, 2005). Furthermore, studies have shown that the gender difference in physical aggression is evident even before the preschool years (Tremblay, 2006), and it is fully expressed by puberty (Volavka, 1995, 1999)." (Wright et al., 2008). In addition, it strongly appears that these differences are biologically linked rather than the result of differential socialization because the differences in criminality between males and females exist across cultures.

In many ways, the human brain is formed during early childhood. While learning occurs after that point, it is how the brain develops during early childhood that impacts the ability to learn. "Early formation of synaptic paths is crucial for the healthy development of all cognitive functions; for instance, if an infant does not sufficiently form these "lines of communication" in his or her brain by a certain stage in the first months of life, then basic skills (such as sight or verbal communication) can be lost permanently. In the meantime, new brain cells are constantly being developed, even into old age, but such alterations in the brain are largely contingent on what the individual has experienced in his or her environment" (Wright et al., 2008). Therefore, one of the factors that can impact adult propensity to commit violence is whether the brain had the opportunity to develop normally in very early childhood. Of course, both social and biological factors can impact early brain development.

In many ways, criminals are not thought to respond to external stimuli in the same manner as non-criminals, and it is believed that there may be an underlying biological basis for these differences. The auto-nomic nervous system (ANS) is the part of the nervous system beyond the conscious control of the individual and is split into the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system prepares the body for action while the parasympathetic nervous system handles baseline tasks. In many criminals, the relationship between the two parts of the ANS operates differently than in non-criminals, with them exhibiting lower hear rates. These lower heart rates are thought to be the result of "a phenomenon known as vagotonia, which is a predominance of the parasympathetic autonomic processes over the sympathetic system. Vagotonia is thought to occur from overstimulation of the vagus nerve, which encourages the release of insulin from the pancreas and often leads to hypoglycemia, which is also linked to criminality" (Wright et al., 2008). This is also thought to lead to slower brain-wave functioning. Therefore, these biological factors are linked to criminality.