Schwartz, J. A., & Beaver, K. M. (2016). Revisiting the association between television viewing in adolescence and contact with the criminal justice system in adulthood. Journal of Interpersonal Violence, 31(14), 2387-2411.
Abstract: A substantial number of previous studies have reported significant associations between television viewing habits and a host of detrimental outcomes including increased contact with the criminal justice system. However, it remains unclear whether the results flowing from this literature are generalizable to other samples and whether previously observed associations are confounded due to uncontrolled genetic influences. The current study addresses these limitations using the National Longitudinal Study of Adolescent to Adult Health (Add Health). The results of the preliminary models, which do not include controls for genetic influences, produced a pattern of results similar to those previously reported in the extant literature. The results of the genetically informed models revealed that the associations between television viewing and antisocial outcomes are not causal, but rather are driven by uncontrolled genetic influences. Further replication is required, but these findings suggest that results drawn from the extant literature may not be trustworthy.
Schwartz, J. A., Beaver, K. M., & Barnes, J. C. (2015). The association between mental health and violence among a nationally representative sample of college students from the United States. PLOS ONE, 10(10), e0138914.
Abstract: Objectives: Recent violent attacks on college campuses in the United States have sparked discussions regarding the prevalence of psychiatric disorders and the perpetration of violence among college students. While previous studies have examined the potential association between mental health problems and violent behavior, the overall pattern of findings flowing from this literature remain mixed and no previous studies have examined such associations among college students. Methods: The current study makes use of a nationally representative sample of 3,929 college students from the National Epidemiologic Study on Alcohol and Related Conditions (NESARC) to examine the prevalence of seven violent behaviors and 19 psychiatric disorder diagnoses tapping mood, anxiety, personality, and substance use disorders. Associations between individual and composite psychiatric disorder diagnoses and violent behaviors were also examined. Additional analyses were adjusted for the comorbidity of multiple psychiatric diagnoses. Results: The results revealed that college students were less likely to have engaged in violent behavior relative to the non-student sample, but a substantial portion of college students had engaged in violent behavior. Age- and sex-standardized prevalence rates indicated that more than 21% of college students reported at least one violent act. In addition, more than 36% of college students had at least one diagnosable psychiatric disorder. Finally, the prevalence of one or more psychiatric disorders significantly increased the odds of violent behavior within the college student sample. Conclusions: These findings indicate that violence and psychiatric disorders are prevalent on college campuses in the United States, though perhaps less so than in the general population. In addition, college students who have diagnosable psychiatric disorders are significantly more likely to engage in various forms of violent behavior.
Schwartz, J. A., Savolainen, J., Aaltonen, M., Merikukka, M., Paananen, R., & Gissler, M. (2015). Intelligence and criminal behavior in a total birth cohort: An examination of functional form, dimensions of intelligence, and the nature of offending. Intelligence, 51, 109-118.
Abstract: Intelligence has been found to predict a wide range of criminal and antisocial behaviors, including violent and chronic offending. The results from this literature have shown that individuals with lower intelligence levels (typically measured as IQ) tend to be more likely to engage in criminal behavior. Despite the pervasiveness of this basic finding, many aspects of the IQ-offending relationship remain unclear, such as the functional form of the association. Some perspectives expect a discrete or curvilinear association, while others assume a more incremental or linear pattern. The current study contributes to this literature by examining the functional form of the IQ-offending association in a total birth cohort of Finnish males born in 1987. Criminal offending was measured with nine different indicators from official records and intelligence was measured using three subscales (verbal, mathematical, and spatial reasoning) as well as a composite measure. The results show consistent evidence of mostly linear patterns, with some indication of curvilinear associations at the very lowest and the very highest ranges of intellectual ability. We discuss the implications of these findings for future research.
Schwartz, J. A. (2015). Socioeconomic status as a moderator of the genetic and shared environmental influence on verbal IQ: A multilevel behavioral genetic approach. Intelligence, 52, 80-89.
Abstract: An expansive literature has revealed that human intelligence is under genetic influence. In an effort to further elucidate the role of genetic influences on intelligence, studies have examined the potential role that family-level socioeconomic status (SES) plays in the moderation of genetic factors. Results have been mixed, but the majority of studies have found that genetic factors have greater influence on IQ in the presence of higher levels of SES. The current study aims to contribute to this line of research by examining the role of school-level SES in moderating genetic and environmental influences on verbal intelligence at the individual level. A sample of sibling pairs from the National Longitudinal Study of Adolescent to Adult Health (Add Health) was used to estimate a series of genetically informed multilevel statistical models. The results indicate that genetic factors have a greater influence on verbal IQ for students who attend schools with higher levels of SES, and shared environmental factors have a greater influence on verbal IQ for students who attend schools with lower levels of SES, but only at extremely high and low levels of SES (scoring within the top or bottom 10th percentiles).
Schwartz, J. A., Connolly, E. J., Beaver, K. M., Nedelec, J. L., & Vaughn, M. G. (2015). Proposing a pedigree risk measurement strategy: Capturing the intergenerational transmission of antisocial behavior in a nationally representative sample of adults. Twin Research and Human Genetics, 18(06), 772-784.
Abstract: An impressive literature has revealed that variation in virtually every measurable phenotype is the result of a combination of genetic and environmental influences. Based on these findings, studies that fail to use genetically informed modeling strategies risk model misspecification and biased parameter estimates. Twin- and adoption-based research designs have frequently been used to overcome this limitation. Despite the many advantages of such approaches, many available datasets do not contain samples of twins, siblings or adoptees, making it impossible to utilize these modeling strategies. The current study proposes a measurement strategy for estimating the intergenerational transmission of antisocial behavior (ASB) within a nationally representative sample of singletons using an extended pedigree risk approach that relies on information from first- and second-degree relatives. An evaluation of this approach revealed a pattern of findings that directly aligned with studies examining ASB using more traditional twin- and adoption-based research designs. While the proposed pedigree risk approach is not capable of effectively isolating genetic and environmental influences, this overall alignment in results provides tentative evidence suggesting that the proposed pedigree risk measure effectively captures genetic influences. Future replication studies are necessary as this observation remains preliminary. Whenever possible, more traditional quantitative genetic methodologies should be favored, but the presented strategy remains a viable alternative for more limited samples.
Schwartz, J. A., & Beaver, K. M. (2015). A partial test of Moffitt’s developmental taxonomy: Examining the role of genetic risk. Justice Quarterly, 32(5), 768-791.
Abstract: A developing line of research indicates that behavioral patterns associated with the typologies identified in Moffitt’s developmental taxonomy may be influenced by genetic factors. Based on these findings, the current study examines whether Moffitt’s etiological explanations of life-course persistent offenders, adolescence-limited offenders, and abstainers have merit after controlling for genetic influences. To do so, a sample of twins drawn from the National Longitudinal Study of Adolescent Health were examined. The results revealed that genetic influences significantly predicted entry into each of the typologies identified by Moffitt even after controlling for theoretically relevant factors. Implications of the findings and suggestions for future research are discussed.
Schwartz, J. A. (2017). Long-term Physical Health Consequences of Perceived Inequality: Results from a Twin Comparison Design. Social Science & Medicine, 187, 184-192.
Rationale: Previous research has identified long-term exposure to stress as a risk factor for negative mental and physical health outcomes. This pattern of findings suggests that environmental stimuli that evoke feelings of stress or strain may also result in physiological responses, which may accumulate over the life course and ultimately increase the overall risk of various physical health conditions. This physiological “wear and tear” resulting from sustained levels of stress or strain has been previously operationalized as allostatic load (AL), a comprehensive indicator of stress exposure.
Objective: The current study examines the association between one potential environmental stressor--perceived inequality--and AL with a research design aimed at addressing both observed and unobserved sources of confounding; it also employs a more comprehensive AL measure (comprised of 24 biomarkers tapping seven physiological systems) than previous studies.
Method: The biomarker twin sample from the Midlife Development in the United States (MIDUS) study was used to estimate a series of twin comparison models, which include controls for latent sources of influence that cluster within families. The sibling comparison models also included additional controls for lifestyle choices, overall physical health, and demographics which may confound the examined associations.
Results: The results revealed significant associations between greater perceptions of inequality and greater overall levels of AL. The association persisted even after including controls for both observed and unobserved influences that may confound the examined associations but was limited to more recent measures of perceived inequality. Associations involving earlier measures of perceived inequality, along with a lifetime measure, failed to reach conventional levels of significance.
Conclusion: Perceived inequality appears to be a robust predictor of AL and potentially contributes to subsequent physical health problems, particularly for more proximate forms of perceived inequality.
Schwartz, J. A., Connolly, E. J., Nedelec, J. L., & Beaver, K. M. (In Press). An Investigation of Genetic and Environmental Influences Across The Distribution of Self-Control. Criminal Justice and Behavior.
Abstract: Previous research illustrating a robust, negative association between self-control and various forms of delinquent and criminal behavior has resulted in a more concentrated focus on the etiological development of self-control. The current study aims to contribute to this literature using a sample of twin and sibling pairs from the National Longitudinal Study of Adolescent to Adult Health (Add Health) to examine genetic and shared environmental influences across levels of self-control. The results of modified DeFries–Fulker (DF) equations revealed that genetic and shared environmental influences were distributed in a nonlinear pattern across levels of self-control. Subsequent biometric quantile regression models revealed that genetic influences on self-control were maximized in the 50th and 60th percentiles, and minimized in the tails of the distribution. Shared environmental influences were nonsignificant at all examined quantiles of self-control with only one exception. The theoretical importance of utilizing genetically informed modeling strategies is discussed in more detail.
Schwartz, J. A., & Portnoy, J. (2017). Lower Catecholamine Activity is Associated with Greater Levels of Anger. International Journal of Psychophysiology, 120, 33-41.
Previous research has revealed a consistent association between heart rate at rest and during stress and behavioral problems, potentially implicating autonomic nervous system (ANS) functioning in the etiological development of antisocial behavior. A complementary line of research has focused on the potential independent and interactive role of the two subsystems that comprise the ANS, the parasympathetic nervous system (PNS) and the sympathetic nervous system (SNS), on behavioral problems. The current study aims to contribute to the existing literature by examining the influence of heart rate (HR) reactivity, high-frequency heart rate variability (HF- HRV) reactivity, and catecholamine activity on a comprehensive measure of anger in a large, nationally-re- presentative sample of adults from the United States. Results from a series of structural equation models (SEMs) revealed that catecholamine activity was most consistently linked to anger, while associations involving HR and HF-HRV reactivity were nonsignificant. Additional analyses revealed that HF-HRV did not significantly moderate the association between catecholamine activity and anger. These findings highlight the importance of SNS activity in the development of more reactive forms of aggression such as anger.
Schwartz, J. A., Connolly, E. J., & Brauer, J. R. (In Press). Head Injuries and Changes in Delinquency from Adolescence to Emerging Adulthood: The Importance of Self-Control as a Mediating Influence. Journal of Research in Crime and Delinquency.
Abstract: Objectives: The current study examines whether head injuries suffered ear- lier in the life course are associated with subsequent changes in self-control and delinquency.
Methods: Latent growth curve models and path analysis are used to analyze the developmental trajectories of self-control and delinquency as well as the potential associations between head injury, self-control, and delinquency among a sample of youth offenders from the pathways to desistance study.
Results: The results revealed significant associations between head injuries and short-term changes in self-control and subsequent increases in aggressive delinquency. Indirect pathway models revealed that lower levels of self-control significantly mediated the association between head injuries and starting levels in aggressive delinquency. The association between head injuries and changes in aggressive delinquency was also significantly mediated by self-control, but the association was negative, indicating that youth who previously suffered head injuries desisted from aggressive delinquency at a slightly faster rate than their noninjured peers. Additional analyses revealed that, despite accelerated rates of decline, injured youth engaged in significantly higher levels of aggressive delinquency throughout the entire observation period.
Conclusion: Head injuries represent one environmental factor that may influence delinquent behaviors through their influence on biological and developmental processes.