Nicholas Kavish

On the relationship between psychopathy and general intelligence: A meta-analytic review

Substantial research has investigated the association between intelligence and psychopathic traits. The findings to date have been inconsistent and have not always considered the multi-dimensional nature of psychopathic traits. Moreover, there has been a tendency to confuse psychopathy with other closely related, clinically significant disorders. The current study represents a meta-analysis conducted to evaluate the direction and magnitude of the association of intelligence with global psychopathy, as well as its factors and facets, and related disorders (Antisocial Personality Disorder, Conduct Disorder, and Oppositional Defiant Disorder). Our analyses revealed a small, significant, negative relationship between intelligence and total psychopathy (r = -.07, p = .001). Analysis of factors and facets found differential associations, including both significant positive (e.g., interpersonal facet) and negative (e.g., affective facet) associations, further affirming that psychopathy is a multi-dimensional construct. Additionally, intelligence was negatively associated with Antisocial Personality Disorder (r = -.13, p = .001) and Conduct Disorder (r = -.11, p = .001), but positively with Oppositional Defiant Disorder (r = .06, p = .001). There was significant heterogeneity across studies for most effects, but the results of moderator analyses were inconsistent. Finally, bias analyses did not find significant evidence for publication bias or outsized effects of outliers.Over recent decades, a growing body of research has accumulated concerning the relationship between indicators of general intelligence and the personality construct known as psychopathy. Both traits represent key correlates of life outcomes, predicting everything from occupational and economic success, to various indicators of prosocial behavior (including avoiding contact with the criminal justice system). The findings to date regarding the association of the two traits, however, have been somewhat inconsistent. Thus, there remains a need for a more systematic investigation of the extant empirical literature. The current study reports a meta-analysis conducted to evaluate the direction and overall effect size of the relationship between these two constructs. Our analyses revealed a small, but significant, negative effect of intelligence on psychopathy. The results and impact of possible moderating variables such as type of intelligence test used are discussed. Finally, the study limitations, and possible directions for further research on this issue are detailed prior to concluding.

Resting heart rate and psychopathy: Findings from the Add Health Survey

Despite the large body of research linking low resting heart rate to antisocial behavior broadly, significantly less work has been done linking heart rate to psychopathic traits. The small body of research on the topic that has been conducted, has found an overall inverse relationship between the two constructs. A significant minority of studies have found the opposite results, however, and many prior studies have been limited by small sample sizes and unrepresentative samples. The current study attempts to help clarify the relationship between resting heart rate and psychopathic traits in a large, nationally representative sample using an alternative measure of psychopathic traits that is less focused on antisocial processes. No significant relationship between heart rate and psychopathic traits, or heart rate and a measure of cold heartedness, was found after controlling for age, sex, and race. Implications of the findings, study limitations, and directions for future research are discussed.

Criminology’s Modern Synthesis: Remaking the Science of Crime with Darwinian Insight

For over a century and half now, the biological sciences have been moored to a unifying set of principles—that life on earth is ancient; that all life is descended from a common ancestor; that the diversity of species on the planet is the product of random genetic mutations and a combination of random genetic drift and nonrandom selection favoring alleles promoting survival and reproduction; and that these processes apply to every living organism (Buss, 2015; Darwin, 1859; Dennett, 1995; Goetz & Shackelford, 2006; Pinker, 1997; Stearns, 2000; Wright, 1994). Yet, for decades (and decades) in the social sciences, scholars have conducted their work as if humans, for all practical purposes, were exempted from these universal evolutionary processes (Horowitz, Yaworsky, & Kickham, 2014; Maynard, Boutwell, Vaughn, Naeger, & Dell, 2015; Pinker, 2002). At most, these scholars allowed for the fact that our bodies may have been historically sculpted by natural selection, but the instant we invented culture we were freed from the laws of nature and exempted from the pressures of selection forces (Cochran & Harpending, 2009). Consequently, the role of biology in some disciplines has come a distant second to the role of culture and socialization in exploring and explaining human nature and human differences (Pinker, 2002; Winegard, Winegard, & Boutwell, 2017).

Testing the causal hypothesis that repeated bullying victimization leads to lower levels of educational attainment: A sibling-comparison analysis

ABSTRACT Existing research suggests that repeated bullying victimization is associated with lower levels of educational attainment. However, it is difficult to ascertain whether a true causal association exists since previously reported associations may be confounded by genetic and shared environmental factors that affect both repeated bullying victimization and overall educational attainment. The present study aimed to address this issue by analyzing a sample of sibling pairs from the National Longitudinal Survey of Youth 1997 to examine between-family associations (where observable confounds are controlled for) and within-family associations (where observable and unobserved genetic and shared environmental confounds are controlled for). The results revealed that bullying victimization significantly reduced the odds of high school and college graduation when estimating between-family effects, but were rendered nonsignificant once within-family effects were controlled for. Implications of these results for future research on bullying victimization and educational attainment are discussed.

The Association of Externalizing and Internalizing Problems with Indicators of Intelligence in a Sample of At-Risk Children

To date, a substantial body of research exists suggesting an association between indicators of intelligence and various deleterious outcomes, including externalizing and internalizing behavioral problems. Much of this research, however, has focused on samples drawn from the general population, thus it remains less clear how (and if) intelligence relates to problem behaviors in samples of highly at-risk individuals. The current study seeks to contribute to this knowledge base by examining the associations between intelligence and internalizing, externalizing, and total scores on the Child Behavioral Checklist in a sample of approximately 2,500 highly disadvantaged and at-risk respondents. While the two measures of intelligence performed differently, there emerged some association between overall lower IQ and higher total behavioral problem scores. There was some evidence that low IQ also predicted higher internalizing scores, but this relationship varied greatly by measure and model. Results, limitations, and implications of the current study are discussed.

Additive genetic and environmental contributions to the longitudinal association between violent victimization and depression

The present study analyzed unique and common additive genetic and environmental influences on self reported violent victimization and major depression across 8 years of life. Young adults (Mage = 20.14, SD = 3.94), including 473 full sibling pairs and 209 half sibling pairs (N = 1,364) from the Child and Young Adult Sample of the National Longitudinal Survey of Youth were analyzed to examine the association between violent victimization and depression from late adolescence to young adulthood, estimate how much additive genetic and environmental factors account for variation in liability for single and repeat violent victimization and major depression, and compare the magnitude of genetic and environmental influences on the covariance in liability between single and repeated victimization and major depression. Cross lagged models revealed that while victimization was associated with an increased risk for depression during late adolescence, major depression was more strongly and consistently associated with increased risk for future victimization across young adulthood. Biometric models revealed that 20% of the association between single victimization and major depression was accounted for by common additive genetic influences, while 30% of the association between repeat victimization and major depression was accounted for by common additive genetic influences. Results and implications are discussed.Research suggests victims of violent crime are more likely to suffer from major depressive disorder (MDD) compared to non-victims. Less research has utilized longitudinal data to evaluate the directionality of this relationship or examined the genetic and environmental contributions to this association across the life course. The current study evaluated 473 full-sibling pairs and 209 half-sibling pairs (N = 1,364) from the National Longitudinal Survey of Youth (Mage = 20.14, SD = 3.94). Cross-lagged models were used to examine the directionality of effects between violent victimization and MDD over time. Biometric liability models were used to examine genetic and environmental influences on single and chronic violent victimization and MDD. Violent victimization was associated with increases in MDD during late adolescence, but MDD was more associated with increased risk for violent victimization across young adulthood. Biometric analysis indicated that 20% and 30% of the association between MDD and single and chronic victimization, respectively, was accounted for by common genetic influences. Results from the current study suggest individuals who exhibit symptoms of MDD are at higher risk for chronic victimization rather than developing MDD as a result of victimization. Shared genetic liability accounted for between 20 to 30% of this longitudinal relationship.

On the Relation Between General Intelligence and Psychopathic Traits: An Examination of Inpatient Adolescents

A substantial literature has investigated relations between intelligence and psychopathic traits. At the construct level, findings have been mixed, with a small negative relation found. At the facet level however, a positive relation between verbal intelligence and the interpersonal facet of psychopathy, and a negative relation between verbal intelligence and the lifestyle factor of psychopathy emerge. To date, this research has largely neglected adolescents and prior research has focused on clinical and incarcerated populations, while failing to control for psychopathology. The current study sought to address these limitations by examining the relation between intelligence and psychopathy at the construct, facet, and trait level in a sample of inpatient adolescents. At the bivariate level, verbal intelligence was related to dishonest charm, unemotionality, impulsiveness, and manipulation. In regression analyses, however, verbal intelligence lost significance as a predictor of all but impulsiveness. Gender and severity of psychopathology accounted for most significant relations.