The price of crime is enormous. In addition to the monetary costs of the investigative process and the criminal procedure, crime often leads to health and social problems for victims and perpetrators. Approximately 5% of the population is responsible for a sizeable portion of the total amount of crime; thus, preventing high-risk individuals from developing into offenders can provide society with significant savings. To track high-risk individuals and tailor prevention programs, risk factors for criminal behavior must be identified. Knowledge about risk factors for criminal behavior can further expand the range of treatment possibilities and increase their effectiveness.
The thesis that follows will further explore psychological, social, and biological risk factors for criminal behavior and investigate the possibility that stress hyperreactivity (i.e., an excessively active stress response), as indexed by high scores on the Neuroticism personality trait, may mediate the impact of social, as well as biological, risk factors for antisocial behavior.
The first aim of the thesis is to identify psychological, social, and biological risk factors for criminal behavior. The first paper of this dissertation investigates the effects of low birth weight and being a client of Child Protective Services on criminal behavior. The paper has a particular focus on the impact of being placed outside of the home, i.e., in foster care or an institution, and examines whether low birth weight interacts with being placed in out-ofhome care to further increase the risk hypothesized to be associated with low birth weight. The other two papers investigate the influences of genetic variance in monoamine oxidase A (MAOA), serotonin transporter (SLC6A4), and catechol-O-methyltransferase (COMT) genes, which are implicated in serotonergic, dopaminergic, and/or noradrenergic neurotransmission, on criminal behavior. These papers further examine the impacts of personality, the quality of relationship with caregivers, and having witnessed domestic violence. Moreover, Paper II fulfills the second goal of the thesis: To investigate whether stress hyperreactivity may mediate the relationships between social and biological risk factors and criminal behavior. The third objective of the thesis is to investigate possible explanations of why antisocial individuals have been found to score high on Neuroticism, indicating stress hyperreactivity, as well as sensation seeking, indicating stress hyporeactivity (i.e., an unusually diminished stress response). Paper II investigates the possibility that high versus low scores on Neuroticism predict different types of sensation seeking.
The results showed that the personality factor of Neuroticism predicted a prosocial type of sensation seeking, with individuals working in a high-risk profession having high scores and inmates showing low scores. Furthermore, the MAOA polymorphism was related to criminal behavior and the COMT Val158Met polymorphism to sensation seeking. Having a poor relationship with caregivers predicted low scores on sensation seeking. Moreover, Neuroticism was observed to mediate the associations between the relationship with caregivers and the COMT Val158Met polymorphism and sensation seeking. Having witnessed domestic violence and being a client of Child Protective Services predicted an increased risk of criminal behavior. Finally, low birth weight interacted with placement in out-of-home care among clients of Child Protective Services to predict decreased risk of criminal behavior. In conclusion, this dissertation sheds further light on how psychological, social, and biological factors and their interrelationships may impact the development of criminal behavior. Disclosing vulnerability and resilience factors for antisocial behavior, the results may contribute to the detection of high-risk individuals and the formation of effective prevention policies.
List of papers. The papers are removed from the thesis due to publisher restrictions.
Paper I: Abrahamsen, S., & Melinder, A. (2013). Effects of Birth weight and Placement in Out-of- Home Care on Criminal Behavior. (Submitted.)
Paper II: Abrahamsen, S., Foss Haug, K. B., & Melinder, A. (2013). The Importance of COMT, Relationships with Caregivers, and Emotional Stability for Prosocial Sensation Seeking and Antisocial Behavior. (Submitted.)
Paper III: Abrahamsen, S., Foss Haug, K. B., & Melinder, A. (2013). Predicting Incarceration: The Influences of Witnessing Domestic Violence, Variation in the MAOA and SLC6A4 genes, and Emotional Stability. (Submitted.)