Genetics and Criminal Behavior
Genetics and Criminal Behavior
A number of researchers have actually reported study results which show that there is indeed a positive correlation between genetics and crime, suggesting that genetics does play a role in the development of criminal behavior. These assertions are merited, as in as much as the environment within which an individual is raised plays an important role in shaping their personality, or even determining future behavior, genetics brings about a certain predisposition towards certain behavior, and actually affects the individual’s temperament and behaviors in certain situations. It is therefore merited to argue that genetics does play a role, with the role perhaps being that it predisposes an individual to criminal behavior. Wilson and Hernstein (1985) share the same viewpoint and actually identify factors such as sex, body type, intelligence and personality as factors that may affect an individual’s predisposition to crime. Hernstein even goes further in his assertions to argue that other variations such as an extra Y chromosome result in a higher risk of engaging in criminal behavior. Other scholars have argued that due to the fact that conditions such as schizophrenia, anxiety disorders or even depression, it is not really a stretch to implicate genetics in antisocial behavior (Tehrani & Mednick, 2000). Based on the evidence it is clear that the argument for genetics as an important player in the development of criminal behavior cannot be discounted, and the implications it has both presently and in the future for criminal justice must be taken into account.
A number of twin studies have been utilized to explore the relationship between genetics and criminal behavior, as twins provide the perfect subjects in terms of their similar genetic makeup, more so for monozygotic twins. By eliminating the influence of the environment, through the use of adoption, whereby twins from families with a history of antisocial behavior are actually adopted into families where there is no such history, the studies are able to focus solely on the relationship between genetics and criminal behavior. One similar study was actually carried out by Blonigen, Hicks, Krueger, Patrick and Iacono (2005), whereby the researchers attempt to establish the relationship between genetics and psychopathic personality traits. The researchers carry out the study on 626 pairs of twins of both sexes, with the results showing that there was a significant level of genetic influence when it can to psychopathic personality traits, more so with aspects such as impulsive antisociality as well as fearless dominance. These findings while not directly related to crime, serve to highlight the great influence genetics have on personality development. A study by Joseph (2001) also result in similar findings, with monozygotic twins reared apart showing higher rates of concordance when it came to antisocial behavior compared to dizygotic twins reared under similar environments. These findings served to demonstrate a higher degree of heritability in monozygotic twin pairs than in dizygotic ones.
In order to separate the issue of nature and nurture, adoption studies have also been utilized to great effect in an attempt to establish the role of genetics in the development of criminal or antisocial behavior. Adoption studies therefore eliminate the risk of engaging in the nurture versus nature debate, by adopting out children from families with histories of criminal or antisocial behavior to families that have no such history. Tehrani and Mednick (2000) compared the criminality rates of children adopted from mothers with criminal records, with those born of parents with no criminal records and found that the adopted children from incarcerated mothers had higher rates of criminal convictions compared to the control group, further reaffirming the heritability of criminal behavior. Joseph (2001) concurs with these findings and actually compares them to a study in Denmark, with similar findings, with a biological component for property crimes being found, in that children born from fathers with a history of committing property crimes were found to develop similar records of property crimes. These findings were actually similar to those of Cloninger and Gottesman (1987), who found that heritability when it came to violent offenders, stood at 0.50, while that for property offenders stood at 0.78, clearly indicating that there was indeed a higher likelihood of the existence of heritability, more so when it came to property crimes. Moffitt (1993) provides a different approach also evident in other studies, as the researcher takes into account the role environmental factors play in the development of recidivism, and actually highlights two types of criminal behavior, one that actually occurs during adolescence and disappears, and one that persists throughout the individual’s life, suggesting that the former can be attributed to environmental factors, while the latter to genetic or biological causes. This study by Moffitt also serves to highlight a different approach towards interpreting results on criminal behavior, by suggesting that criminal behavior observed after adolescence and essentially after a change in environment can actually be attributed to an individual’s genetic predisposition to crime, more so if the criminal or antisocial behavior begun prior to the change in environment.
There is however a different dimension to the debate, one that takes other biological factors into account, these factors are like gender, testosterone and brain dysfunction, with particular focus being on neurochemistry. Statistics that perhaps further serve to emphasize these research findings are those that show a clear disparity when it comes to comparisons of criminal behavior based on gender. Studies such as those of Hindelang (1978) and Steffensmeier and Allan (1996) have found the rates of offending amongst males are almost four times those of females, serving to bring to the fore the roles played by biological factors in criminality. Vaske, Wright, Boisvert and Beaver (2011) further explore the potential role of genetics in this disparity and find that indeed, females do exhibit a higher genetic risk threshold for engaging in criminal behavior. Studies on 21 young prisoners by Kreuz and Rose (1972) actually served to show a positive link between higher levels of testosterone and increased aggression, more so in a volatile environment, findings which one could also use to explain the gender differences in criminality.
Even though there is some merit to assertions that genetics do play a role in the development of criminal behavior, it is an area that still needs further research. Important discoveries and approaches are however being made towards making the research findings more credible, through the use of adoption studies, as well as monozygotic and dizygotic twin studies, aimed at eliminating the environmental aspect of the debate. There is however increasing evidence that indeed, genetics alone does not really cause criminal behavior, but rather simply predisposes an individual to such criminal behavior. This therefore makes it quite difficult to completely segregate and determine the degree to which genetics plays a role in criminal behavior. In addition, this creates a difficult situation for research, as it makes it quite difficult to identify specific genes that can be associated with crime or a predisposition to the commitment of crimes. Despite these challenges, my opinion on the matter is that there is room for further research, and that these findings must not be dismissed or taken lightly. This is more so when one considers that establishing whether or not a specific gene predisposes an individual to criminal behavior, may actually help in the control of crime. Presently, the police department should definitely consider the various study findings, as there is significant evidence of heritability when it comes to criminal behavior and as such, prior criminal history within the family can be used to predict the probability of future criminal behavior, necessitating closer observation.
Suggestions of the existence of a criminal gene would however have far reaching consequences, more so for the criminal justice system. This would actually be dangerous on two levels: at the level of the potential perpetrator, as it would result in discrimination and undue suspicion, regardless of whether or not the individual has engaged in criminal behavior. Secondly, it would grossly affect the judicial system as well as sentencing, as it would take the blame away from the individuals committing the crimes and put it squarely on genes. If proven to be true, and the existence of a criminal gene becomes a reality, the criminal justice system would be radically reformed, because the American criminal justice system, similar to most, works on the fundamental principle that punishment should be proportional to the degree of blameworthiness, meaning that by establishing that an individual was already fated to commit a crime (predeterminism), we would be shifting the blame away from them, resulting in a lighter sentence not proportional to the crime committed (Wilson, 2011).
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Joseph, J. (2001). Is crime in the genes? A critical review of twin and adoption studies ofcriminality and antisocial behavior. The Journal of Mind and Behavior, 22, 179-218.Kreuz, L., & Rose, R. (1972). Assessment of Aggressive Behavior and Plasma Testosteronein a Young Criminal Population. Psychosomatic Medicine 34(4), 321-332.
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