Genetic influences on being processed through the criminal justice system: results from a sample of adoptees

Forensic Value of Genetic Variants Associated with Anti-Social Behavior

Insanity defense is sometimes invoked in criminal cases, and its demonstration is usually based on a multifactorial contribution of behavioural, clinical, and neurological elements. Neuroradiological evidence of structural alterations in cerebral areas that involve decision-making and moral reasoning is often accepted as a useful tool in these evaluations. On the other hand, the genetic predisposition to anti-social behavior is still controversial. In this paper, we describe two cases of violent crimes committed by young carriers of genetic variants associated with personality disorder; both the defendants claimed to be insane at the time of the crime. We discuss these cases and review the scientific literature regarding the relationship between legal incapacity/predisposition to criminal behavior and genetic mutations. In conclusion, despite some genetic variants being able to influence several cognitive processes (like moral judgement and impulse control), there is currently no evidence that carriers of these mutations are, per se, incapable of intentionally committing crimes.

The Association Between Genetic Predisposition and Parental Socialization: An Examination of Gene-Environment Correlations Using an Adoption-Based Design

An extensive body of research has examined the role that genetic influences play in the development of antisocial behavior. Even so, there remains much that is unknown regarding the intersections among antisocial behavior, environments, and genetic influences. The current study is designed to shed some light on this issue by examining whether gene-environment correlations are present in the lives of adopted adolescents. More specifically, this article seeks to contribute to scholarship efforts aimed at understanding whether biological parents' antisocial behavioral phenotypes-behaviors often attributed to an increased likelihood of receiving a genetic propensity for antisocial behaviors-predict variation in environments that are experienced by their adopted-away offspring. To do so, the biological parents of adoptees were assessed and used to identify ways in which children elicit certain responses from their adoptive parents based, in part, on their genotype. Correlational analyses were calculated on a sample of adoptees (the final analytic sample ranged between n = 229 and n = 293) drawn from the National Longitudinal Study of Adolescent to Adult Health (Add Health). The results of the study revealed very little evidence of gene-environment correlations. The implications of these findings are considered.

The association between the MAOA 2R genotype and delinquency over time among men: the interactive role of parental closeness and parental incarceration

Using a panel of 6,001 males from the National Longitudinal Study of Adolescent and Adult Health, we examine potential moderation by paternal incarceration and parent-child closeness altering the relationship between the rare 2R MAOA genotype and delinquency. By jointly examining moderation patterns for both the mother and father with the transmission of the MAOA genotype from mother to son, we are able to make inferences about the specific genetic model that best explains these outcomes. In line with prior research, we find a direct relationship between the MAOA 2R genotype and delinquency, independent of parental incarceration and closeness. Examining moderation patterns, we find that delinquency risk for the 2R allele is buffered for males close to their biological or social father, but not their biological mother. We conclude that the 2R delinquency association is not due to passive gene-environment correlation but is best characterized as a social control gene-environment interaction.

A Swedish national adoption study of criminality

BACKGROUND

To clarify the role of genetic and environmental factors in criminal behavior (CB), we examined all CB and violent and non-violent subtypes (VCB and NVCB, respectively) in a Swedish national sample of adoptees and their relatives.

METHOD

CB was defined by a conviction in the Swedish Crime Register with standard definitions for VCB and NVCB subtypes. We examined adoptees born 1950-1991 (n = 18 070) and their biological (n = 79 206) and adoptive (n = 47 311) relatives.

RESULTS

The risk for all CB was significantly elevated in the adopted-away offspring of biological parents of which at least one had CB [odds ratio (OR) 1.5, 95% confidence interval (CI) 1.4-1.6] and in the biological full and half-siblings of CB adoptees (OR 1.4, 95% CI 1.2-1.6 and OR 1.3, 95% CI 1.2-1.3, respectively). A genetic risk index (including biological parental/sibling history of CB and alcohol abuse) and an environmental risk index (including adoptive parental and sibling CB and a history of adoptive parental divorce, death, and medical illness) both strongly predicted probability of CB. These genetic and environmental risk indices acted additively on adoptee risk for CB. Moderate specificity was seen in the transmission of genetic risk for VCB and NVCB between biological parents and siblings and adoptees.

CONCLUSIONS

CB is etiologically complex and influenced by a range of genetic risk factors including a specific liability to CB and a vulnerability to broader externalizing behaviors, and by features of the adoptive environment including parental CB, divorce and death. Genetic risk factors for VCB and NVCB may be at least partially distinct.

Exploring whether genetic differences between siblings explain sibling differences in criminal justice outcomes

Research has revealed that despite many similarities, siblings raised within the same household have also been found to be markedly different from one another. Behavioral differences between siblings have been primarily attributed to differential exposure to a wide variety of environmental influences. The potential role that between-sibling genetic differences play in the development of behavioral differences has been overlooked in the extant literature. The current study examines the association between differences in three dopaminergic polymorphisms (DAT1, DRD2, and DRD4) and differences in arrest, incarceration, and multiple arrests between siblings. Between-sibling difference scores were estimated for each examined polymorphism and each criminal justice outcome measure (along with all controls). Ordinary least squares (OLS) regression models were estimated to examine the potential association between genetic differences between siblings and differences in experiences within the criminal justice system. Models were estimated for the full sample and then for the same-sex male and female subsamples separately. The results provide preliminary evidence that between-sibling differences in some of the examined dopaminergic polymorphisms are associated with differences in contact with the criminal justice system. Findings are discussed in more detail and suggestions for future research are also provided.

The association between adult mortality risk and family history of longevity: the moderating effects of socioeconomic status

Studies consistently show that increasing levels of socioeconomic status (SES) and having a familial history of longevity reduce the risk of mortality. But do these two variables interact, such that individuals with lower levels of SES, for example, may experience an attenuated longevity penalty by virtue of having long-lived relatives? This article examines this interaction by analysing survival past age 40 based on data from the Utah Population Database on an extinct cohort of men born from the years 1840 to 1909. Cox proportional hazards regression and logistic regression are used to test for the main and interaction mortality effects of SES and familial excess longevity (FEL), a summary measure of an individual's history of longevity among his or her relatives. This research finds that the mortality hazard rate for men in the top 15th percentile of occupational status decreases more as FEL increases than it does among men in the bottom 15th percentile. In addition, the mortality hazard rate among farmers decreases more as FEL increases than it does for non-farmers. With a strong family history of longevity as a proxy for a genetic predisposition, this research suggests that a gene-environment interaction occurs whereby the benefits of familial excess longevity are more available to those who have occupations with more autonomy and greater economic resources and/or opportunities for physical activity.

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.