Pulling Back the Curtain on Heritability Studies: Biosocial Criminology in the Postgenomic Era

Abstract

Unfortunately, the nature-versus-nurture debate continues in criminology. Over the past 5 years, the number of heritability studies in criminology has surged. These studies invariably report sizeable heritability estimates (∼50 percent) and minimal effects of the so-called shared environment for crime and related outcomes. Reports of such high heritabilities for such complex social behaviors are surprising, and findings indicating negligible shared environmental influences (usually interpreted to include parenting and community factors) seem implausible given extensive criminological research demonstrating their significance. Importantly, however, the models on which these estimates are based have fatal flaws for complex social behaviors such as crime. Moreover, the goal of heritability studies-partitioning the effects of nature and nurture-is misguided given the bidirectional, interactional relationship among genes, cells, organisms, and environments. This study provides a critique of heritability study methods and assumptions to illuminate the dubious foundations of heritability estimates and questions the rationale and utility of partitioning genetic and environmental effects. After critiquing the major models, we call for an end to heritability studies. We then present what we perceive to be a more useful biosocial research agenda that is consonant with and informed by recent advances in our understanding of gene function and developmental plasticity.Questions about nature versus nurture have been a perennial topic of debate in the social sciences. Since the 1970s, these questions have been addressed by a field of study known as behavioral genetics. A major focus of behavioral genetics research has been to partition the variation in an outcome of interest into a proportion caused by genes (heritability) and a proportion caused by the environment (e.g., DiLalla, 2004;Plomin et al., 2012). These heritability studies (also called quantitative genetics, nonmolecular genetics, or biometrics) have compared phenotypes (observed characteristics of individuals) within

The etiologic role of genetic and environmental factors in criminal behavior as determined from full- and half-sibling pairs: an evaluation of the validity of the twin method

“…Most critics of the twin method suggest that its failures -especially violations of the equal environment assumption -would lead to overestimates of the heritability because the 'extra' environmental similarities for MZ twins would increase the MZ-DZ differences and hence bias the heritability estimates upward (Jackson, 1960;Lewontin et al 1985;Pam et al 1996;Joseph, 2002). This indeed is the specific argument put forward by Burt and Simons in their recent highly critical review of twin studies of crime (Burt & Simons, 2014). Furthermore, siblings are typical of the general population and do not share with twins the higher obstetric risks and lower birth weights (Bryan, 1992;Bush & Pernoll, 2007).…”

“…However, there has been a long history of criticisms of the twin method that have raised questions about its validity (Jackson, 1960;Lewontin et al 1985;Pam et al 1996;Joseph, 2002). These concerns have been highlighted in a recent review in a prominent criminology journal, which argued that twin studies of crime were so flawed that further use of this method should be halted (Burt & Simons, 2014).…”

What can genes tell us about the relationship between education and health?

“…An additional concern is whether there are limitations in generalizing from twins to a larger population (Joseph, 2002). This and other important limitations of twin and family based estimates of heritability were detailed in a recent critique of the notion of heritability within criminological research (Burt and Simons 2014). Hence, it is important to consider other approaches to estimate the contribution of genetic variation to phenotypic variation.…”

“…However, there are serious questions regarding the generalizability of samples of identical twins (Burt and Simons 2014). Alternative methods are available that avoid this limitation.…”

A novel sibling-based design to quantify genetic and shared environmental effects: application to drug abuse, alcohol use disorder and criminal behavior

“…Twins also have a distinct intra-uterine experience and form, it is claimed, a unique psychological relationship so that results derived from them cannot be extrapolated to more typical human populations. Many efforts have been made to empirically address these criticisms (Kendler, 1983; Kendler & Prescott, 2006; Barnes et al 2014; LoParo & Waldman, 2014) but the debate continues as witnessed by a recent review in a prominent criminology journal, which argued that twin studies were so flawed that their further use should be banned (Burt & Simons, 2014). The problem of the accuracy of twin heritability estimates has recently taken on a new urgency given increasing efforts to understand the origins of the ‘missing heritability’ problem – the differences in heritability estimates derived from twin studies v. from statistical tools applied to genome-wide molecular variants [Manolio et al 2009; Lee et al 2011; Cross-Disorder Group of the Psychiatric Genomics Consortium (PGC-CDG) 2013; Golan et al 2014; Goldman, 2014; Wray & Maier, 2014].…”