Joseph L. Nedelec

DEMONSTRATING THE VALIDITY OF TWIN RESEARCH IN CRIMINOLOGY

In a recent article published in Criminology, Burt and Simons (2014) claimed that the statistical violations of the classical twin design render heritability studies useless. Claiming quantitative genetics is “fatally flawed” and describing the results generated from these models as “preposterous,” Burt and Simons took the unprecedented step to call for abandoning heritability studies and their constituent findings. We show that their call for an “end to heritability studies” was premature, misleading, and entirely without merit. Specifically, we trace the history of behavioral genetics and show that 1) the Burt and Simons critique dates back 40 years and has been subject to a broad array of empirical investigations, 2) the violation of assumptions in twin models does not invalidate their results, and 3) Burt and Simons created a distorted and highly misleading portrait of behavioral genetics and those who use quantitative genetic approaches. “The flaws of twin studies are not fatal, but rather seem no worse (and may be better) than the flaws of the typical causal study that relies on observational data.” (Felson, 2012: ii)

MATHEMATICAL PROOF IS NOT MINUTIAE AND IRREDUCIBLE COMPLEXITY IS NOT A THEORY: A FINAL RESPONSE TO BURT AND SIMONS AND A CALL TO CRIMINOLOGISTS†

KEYWORDS: biosocial, assumptions, twinsIn their initial article, Burt and Simons (2014) laid out a range of specific criticismsof twin-based research. They argued that violations of the statistical assumptions thatunderpin this line of work result in upwardly biased estimates of heritability and down-wardlybiasedestimatesofenvironmentaleffects.AccordingtoBurtandSimons,thefind-ingsgeneratedfrombehavioralgeneticapproachesare“biologicallynonsensical”andare“misguided.” Indeed, Burt and Simons stated, without qualification, that an entire classof statistical models used to analyze twin data are “seriously flawed.” Because behavioralgenetic designs suffer from “fatal flaws,” they argued, twin-based research designs andtheir associated statistical methods should be put to an “end in criminology.”We examined their assertions carefully. We found that Burt and Simons (2014) cherry-picked the studies they cited in support of their position regarding the biasing impact ofthe equal environments assumption (EEA), something they openly admit in the onlinesupporting information of their rejoinder (Burt and Simons, 2015, this issue). Specifically,theystate,“wefocusedonarticlesthatshowedthattheEEAisnotavalidassumption”tosupport their claim that heritability estimates from behavioral genetic studies are chron-ically overestimated as a result of violations of this assumption. In fact, they relied pri-marily on a single source (Joseph, 1998, 2004, 2006, 2010) for their critique. Notably, wefound that they failed to cite the vast majority of the more than 60 studies that tested forviolations of the EEA—a body of work that is inconsistent with their claims.

Adolescent Life History Strategy in the Intergenerational Transmission and Developmental Stability of Substance Use

Research suggests that fast life history strategy (LHS) may be a primary driver of substance use among young adults. However, a recent study reported that (a) young adult fast LHS did not subsume all theorized indicators of LHS during this period and (b) fast LHS among parents did not predict young adult fast LHS or liability for use of common substances. In this study, we used structural equations and national data to test whether these findings generalized to adolescence. In addition, given that LHS and substance use share genetic and neuropsychological bases, we examined whether fast LHS could explain the developmental stability of substance use. Overall, our results extend the findings discussed above and suggest that fast LHS fully explains the developmental stability of substance use among youth. We discuss implications for life history models, research applying life history theory and substance use, and substance abuse prevention and treatment.

The future of biosocial criminology

Biosocial criminology is the fastest growing line of research within the field of criminology. Even so, there remain significant challenges to this perspective, including biased journal editors, unqualified reviewers, discrimination in hiring, and a lack of courses taught on biosocial criminology. This study reviews these barriers and discusses what needs to be accomplished in the future in order for the biosocial criminological perspective to continue to grow at an exponential rate. We couch our discussion in terms of teaching and training students, departmental hiring, the peer review process, scholarly contributions, and professional development. We conclude by drawing attention to the significant contributions of biosocial criminology and its continued march to the top of the discipline.

The association between sexual behavior and antisocial behavior: insights from an evolutionary informed analysis

There has been a great deal of interest in examining the evolutionary underpinnings to human behaviors, including antisocial behaviors. Very little of this research, however, has seeped into mainstream criminology. The present study seeks to take a cautious step in addressing that gap by examining the role certain evolutionary constructs play in the association between sexual behaviors and antisocial conduct. Analysis of data drawn from the National Longitudinal Study of Adolescent Health revealed that for males and females sexual involvement predicted delinquent involvement both concurrently and longitudinally. Furthermore, items derived from evolutionary psychology, including physical attractiveness, physical maturity, and perceptions about life certainty, predicted sexual involvement for males and females. Our study represents one example of the various ways in which evolutionary explanations can be integrated into criminological theory and research.

The Psychometrics of the Mini-K: Evidence From Two College Samples

Many published studies have employed the Mini-K to measure a single fast–slow life history dimension. However, the internal structure of the Mini-K has not been determined and it is not clear that a single higher order K-factor fits the data. It is also not clear that the Mini-K is measurement invariant across groups such as the sexes. To establish the construct validity of K as well as the broader usefulness of applying life history theory to humans, it is crucial that these psychometric issues are addressed as a part of measure validation efforts. Here we report on three studies that used latent variable modeling and data drawn from two college student samples (ns = 361 and 300) to elucidate the psychometrics of the Mini-K. We found that (a) the Mini-K had a six dimensional first-order structure, (b) the K-factor provided a parsimonious explanation of the associations among the lower order factors at no significant cost to fit, (c) the Mini-K measured the same K-factor across the sexes, (d) K-factor means did not have the same meaning across the sexes and thus the first-order factors should be used in studies of mean sex differences, and finally, (e) the K-factor was only associated with environment and aspects of mating competition in females. Implications and future directions for life history research are discussed.

Religiousness, Spirituality, and Substance Use: A Genetically Sensitive Examination and Critique

A growing literature has linked religiousness and spirituality (R/S) to substance use and abuse. However, it is not clear that R/S has causal effects on substance use. Currently, there is a relative lack of genetically sensitive examinations in the literature attendant to R/S effects. Given that behavioral genetic analyses have illustrated the influence of genetic factors on substance use and adherence to R/S worldviews, genetic confounding is a concern. The current study employed a sample of monozygotic twins discordant on religiousness, spirituality, and spiritual transformation to assess effects on substance use and abuse. Bivariate and multivariate models indicated a general lack of effect of R/S on substance use and abuse but did illustrate a dampening influence of religiousness on general (but not problematic) alcohol use. The findings highlight the importance of controlling for genetic and shared familial factors in examinations of the religiousness–spirituality–substance use nexus.

Genetic Risks and ADHD Symptomatology: Exploring the Effects of Parental Antisocial Behaviors in an Adoption-Based Study

A great deal of research has examined the etiology of attention-deficit/hyperactivity disorder (ADHD) and ADHD symptomatologies. Genetic factors are consistently shown to explain a significant proportion of variance in measures of ADHD. The current study adds to this body of research by examining whether genetic liabilities for criminality and alcoholism have effects on the development of ADHD symptomatologies. Analyses based on a sample of adoptees drawn from the National Longitudinal Study of Adolescent Health (Add Health) revealed that ADHD symptomatologies were elevated among adoptees who had biological mothers and fathers who had been arrested or who were alcoholics. These results suggest that part of the covariation between ADHD and antisocial behaviors may be the result of genetic factors that have general effects across a range of maladaptive outcomes.

Evolutionary Behavioral Genetics of Violent Crime

The goal of this chapter is to provide an overview of the existing literature pertaining to evolutionary behavioral genetics and violent criminal behaviors. In doing so, we provide an introduction to the methodologies that are used to estimate the heritability of violent crime, and we review studies that have estimated the heritability of violent crime. We then offer some background information related to molecular genetics and also examine research that has attempted to isolate the specific genetic polymorphisms that might relate to violent criminal involvement. Finally, we explore the potential role of gene–environment interactions as they relate to the development of violent criminal tendencies and discuss the various explanatory perspectives that are used to explain gene–environment interactions as they relate to crime and violence.

Social Bias and the Development of Self-Control Results From a Longitudinal Study of Children and Adolescents

Gottfredson and Hirschi’s general theory of crime has sparked a tremendous amount of research examining the link between levels of self-control and involvement in delinquent and criminal acts. Recently, studies testing this theory have begun to investigate the factors that are related to the development of self-control. The current study expands on this body of research by examining whether social bias, as measured by the ability to identify facial expressions, contributes to variation in self-control in a sample of children. Analysis of data drawn from the National Survey of Children revealed some evidence that children who had difficulty correctly identifying facial expressions depicting fear and happiness had lower levels of self-control, whereas errors in identifying faces expressing anger were related to higher levels of self-control. The authors discuss the need for Gottfredson and Hirschi’s theory on the development of self-control to be expanded.