Is Violent Behavior in Adult Males (and Adult Females) Caused by Genes, Environment, or Both?
Research Study: Nature (Genes) or Nurture (Environmet) Cause a Violent Behavior Personality
Research studies of genes and genotypes have been conducted to find out if an individual’s violent behavior is a function of nature or nurture. Research has found that the s/s genotype does correlate with violent offenses and violent crimes. Also, negative childhood environments have shown to predispose people toward violent behavior in later life. To conduct one research study, authorities sent 184 Caucasian, male, adult volunteers to the Institute of Forensic Psychiatry of the University of Saarland to be evaluated for legal responsibility or risk assessment. First, the men were told the scope and aim of the study that was being conducted. The men had to give their written consent before participating in this study. They were given a semi-structured interview that was conducted by well-trained psychiatrists. Next, the men were given a neurological exam. The Ethics Committee of the University of the Saarland and the University of Wurzburg gave its approval of this study (Reif, Rosler, Freitag, Schneider, Eujen, Kissling, Wenzler, Jacob, Retz-Junginger, Thome, Klaus-Peter & Retz, 2007). The genotyping was conducted by drawing blood samples and then extracting DNA using a standard method. Statistical analysis was then provided from the findings of this research study.
Researchers' Findings from the Study
The results of this study found that out of the 184 males, 72% of the men had a history of violent behavior. Older males were less likely to exhibit violent behavior. Those individuals who had a history of drug abuse showed to have a higher prevalence toward violent behavior. Personality disorders were more common among the men who had a history of violent behavior. Summing it all up from this study, results are conclusive that genetics (nature) do play a part in determining the likelihood for impulsive violent behavior. (Reif, Rosler, Freitag, Schneider, Eujen, Kissling, Wenzler, Jacob, Retz-Junginger, Thome & Klaus-Peter & Retz, 2007, p. 354-355)
“Aggressive behavior is influenced by variation in genes of the serotonergic circuitry and early-life experience alike. An interaction effect between childhood environment and 5HTT genotype on violent behavior was found - in that high adversity during childhood impacted only the later-life violence if the shorter promoter alleles were present. (Neuropsychopharmacology (2007) 32, 2375-2383; doi: 10-1038/sj.npp.1301359; published online 7 March, 2007).” (Yang, Hujaie, Zhiquin, Hanqing, Haiying & Wei, 2013, p. 6).
Research studies have shown (both) nature and nurture to play an important role in the temperament of a person, such as violent behavior. Many scientific, reliable, and valid studies have been conducted that validate this to be true.
Causal Factors in the Development of Violent Behavior Personality Types in Adult Males (and Adult Females)
Most of the participants in this study had suffered from childhood emotional abuse, which mirrored the findings of other studies that showed experiences of emotional deprivation, exploitation, humiliation, and constant rejection during childhood which is common among violent offenders (Carli et al., 2013; Kolla et al., 2013). Although experiences of emotional abuse seem to be a recurring theme in the childhoods of offenders, the prevalence of physical and sexual abuse was also higher than it was for individuals who were studied in normal and clinical populations (Bifulco et al., 2014; Deblinger, McLeer, Atkins, Ralphe, & Foa, 1989; McFarlane, Groff, O’Brien, & Watson, 2003).” (Schimmenti, Di Carlo, Passanisi & Caretti, 2014, p. 5)
There are physical illnesses, brain disorders, certain neurochemicals (monoamine oxidase (MOA), epinephrine, norepinephrine, dopamine, serotonin), and Post Traumatic Stress Disorder that can cause the violent behavior in individuals. Certain brain traumas (brain injuries) can also exacerbate the prevalence of the violent behavior. (Magnavita, 2012)
Personality is the accumulation, the total, of our “thoughts, emotions and behaviors.” It is also the way in which we interact with other people and how we relate to our world today. Personality is how we see other people, and how we see ourselves. Personality is in a formative state during childhood. It is shaped through the interaction of our genes and our environment. When people have personality disorders, these disorders are caused by “genetic and environmental influences.” What happens many times is: a person’s genes can predispose him “to developing a personality disorder, and a life situation may trigger the actual development.” (Mayo Clinic, 2015)
Magnavita, J.J. (2012). Theories of Personality. San Diego, CA: Bridgepoint Education, Inc. This text is a Constellation™ course digital materials (CDM) title
Mayo Clinic Staff. (2015). Diseases and conditions. Personality disorders. Retrieved online at http://www.mayoclinic.org/diseases-conditions/personality-disorders/basics/causes/con-20030111
Reif, A., Rosler, M. Freitag, C.M., Schneider, M., Eujen, A., Kissling, C., Wenzler, D., Jacob, C.P., Retz-Junginger, P., Thome, J., Klaus-Peter, L. & Retz, W. (2007, Mar. 7). Nature and nurture predispose to violent behavior: Serotonergic genes and adverse childhood environment. Retrieved online at Nature and Nurture Predispose to Violent Behavior article (http://www.nervenklinik.uk-wuerzburg.de/fileadmin/uk/psychiatrie/Dokumente/Forschung/Psychiatric_Neurobiology_and_Bipolar_Disorder_Program/MAO-A_and_violent_crime.pdf
Schimmenti, A., Di Carlo, G., Passanisi, A. & Caretti, V. (2014, Dec. 22). Abuse in Childhood and Psychopathic Traits in a Sample of Violent Offenders. Psychological trauma: Theory, research, practice, and policy. Advance online publication. ISSN number: 1942-9681 (Print). 1942-969X (Electronic). Accession number: 2014-56019-001. Retrieved online at Ashford u. library psycARTICLES database. http://dx.doi.org/10.1037/tra0000023
Yang, C., Huajie, B., Zhiquin, G., Hanqing, Z., Haiying, Y. & Wei, G. (2013, Dec.). A case-control study of allele frequencies of 15 short tandem repeat loci in males with impulsive violent behavior. Shanghai archives of psychiatry. ISSN: 1002-0829. Accession number: 93608152. Doi: 10.3969/j. Vol. 25. Issue 6. Retrieved online at Ashford library EBSCOhost database