What Scientific Research Says About Criminality

15 July 2015
 Categories: Law, Blog


Research in the areas of sociology, psychology, neuroscience and other fields may change the way criminal behavior is viewed and treated in the American justice system eventually. This article will discuss the environmental factors, learned morality, and discoveries in neuroscience.


Medical research indicates that there are genetic factors that can predispose a person to illegal behavior (as discussed below), but sociological studies indicate that these environmental factors are more reliable predictors of violent or serious criminality:

  • Lack of parental supervision.
  • Lack of training on how to care for animals or vulnerable persons, from an early age.
  • Inconsistent or unfair discipline sometimes based on parental whims.
  • Harsh/abusive discipline.
  • Lack of positive reinforcement. Parents fail to "catch their child being good" to give them favorable attention for it.
  • Lack of family unity and few positive ways to spend time together.
  • Disconnection from extended family that normally provides motivation for social compliance and good behavior.
  • Parental substance abuse, poverty, and strife or disruption.
  • Dispiriting educational institutions ("diploma mills") that reinforce hopelessness and fail to equip children with necessary skills and social opportunities.

These factors can produce youths that are despairing and angry, and it is worth noting that a youth that is exposed to wealth and privilege can also grow up in a dysfunctional atmosphere that fosters genetic tendencies to crime.

To counteract poor social conditions, community action and parental education/support need to improve in many areas to thwart delinquency.


Related to this is research that many violent criminals involved in gang activity have developed an erroneous moral code in which retribution has a greater value than compassion. They believe that their behavior is a good thing because violence teaches obedience and can be used to mete out justice.

To motivate these persons to change, they need to be convinced that violence is not necessary or desirable to reach their goals. They also need to develop insight and empathy for others.

Genetic Research and Neuroscience

Some of the modern genetic research and neuroscience has been disturbing to many because it seems to infringe on the notion of free will. Researchers are quick to point out that people may have certain traits and yet do not engage in criminal behavior. It often takes a combination of factors as addressed above.

A Finnish study of 900 convicted criminals including 78 violent offenders showed that the persons who committed the violent crimes had two genes that the others didn't possess. One of these is MAOA gene, which is also nicknamed the "warrior gene" (because of its connection to aggressive behavior) and is involved in controlling the amounts of serotonin and dopamine (chemicals that transmit messages) in the brain. The other gene involved is the CDH13 gene that is associated with ADHD (Attention Deficit Hyperactivity Disorder) and the propensity for substance abuse.

Brain imaging shows differences between criminals with antisocial personalities (people who appear to have no regard for rights of others or for rules/laws) and other people. They have significant reductions in areas in the frontal lobes of their brains. Psychopaths (who have a severe form of antisocial personality disorder) have an 18% reduction in the part of the brain called the amygdala, which has been termed the "seat of emotion." This would explain their emotionless, remorseless behavior.

Some of these traits begin to be apparent early in life and would require prompt intervention. Fortunately, it turns out that the brain is more plastic or malleable than once thought.

To Recap

Research indicates that although there is a genetic component to violent crime, though this may never manifest. However, a learned but corrupted moral code, plus the influence of drugs and alcohol, and a dysfunctional or hopeless environment can switch on these criminal tendencies or make them worse.

While scientists are careful to say that their research should not excuse criminal behavior, these things could be considered mitigating factors in a criminal defense if proved to be present.