Genetic and environmental contributions to the relationship between violent victimization and criminal behavior

Juvenile Violent Victimization and Adult Criminal Outcomes: The Role of Military Service as a Turning Point in Young Adulthood

Previous research has consistently shown that juvenile violent victimization is associated with an increased risk of future criminal involvement, a phenomenon commonly known as victim-offender overlap. Despite a growing interest in the factors underlying this overlap, potential roles of major life transitions and turning points that may interrupt and reshape the nature of this developmental association have garnered less academic attention. Analyzing nationally representative data from waves I, IV, and V of the National Longitudinal Study of Adolescent to Adult Health (Add Health; n = 10,205), this study investigates the association between juvenile violent victimization and adult criminal outcomes (i.e., violent offending, non-violent offending, arrest, and incarceration) and whether this association is moderated by military service with and without combat experience in young adulthood. Employing a series of logistic regression analyses and adjusting for a host of covariates, measures of selection, and criminogenic traits, we found that juvenile violent victimization was significantly associated with greater odds of violent offending, arrest, and incarceration in adulthood. Among individuals with violent victimization histories, military service with no combat experience was associated with a 16% decrease in the odds of incarceration in adulthood. Combat experience, however, was associated with over seven times greater odds of violent offending in adulthood for these individuals. These findings have important implications for theory, research, and practice, and highlight the relevance of life transitions and turning points in general, and military service in particular, in mitigating or perpetuating the criminogenic impacts of violent victimization in the life course.

Genetics and epigenetics of human aggression

There is substantial variation between humans in aggressive behavior, with its biological etiology and molecular genetic basis mostly unknown. This review chapter offers an overview of genomic and omics studies revealing the genetic contribution to aggression and first insights into associations with epigenetic and other omics (e.g., metabolomics) profiles. We allowed for a broad phenotype definition including studies on "aggression," "aggressive behavior," or "aggression-related traits," "antisocial behavior," "conduct disorder," and "oppositional defiant disorder." Heritability estimates based on family and twin studies in children and adults of this broadly defined phenotype of aggression are around 50%, with relatively small fluctuations around this estimate. Next, we review the genome-wide association studies (GWAS) which search for associations with alleles and also allow for gene-based tests and epigenome-wide association studies (EWAS) which seek to identify associations with differently methylated regions across the genome. Both GWAS and EWAS allow for construction of Polygenic and DNA methylation scores at an individual level. Currently, these predict a small percentage of variance in aggression. We expect that increases in sample size will lead to additional discoveries in GWAS and EWAS, and that multiomics approaches will lead to a more comprehensive understanding of the molecular underpinnings of aggression.

A Systematic Review of the Biological Correlates and Consequences of Childhood Maltreatment and Adverse Childhood Experiences

Childhood maltreatment (CM) and adverse childhood experiences (ACEs) are two primary forms of interpersonal victimization that have been associated with a host of deleterious health outcomes. Studies over the past decade have begun to use a range of biologically informed methods to better understand the role biology plays in the relationship between CM, ACEs, and later life outcomes. This line of research has shown that both forms of victimization occur at sensitive periods of development, which can increase the likelihood of "getting under the skin" and influence health and behavior across the life course. This review examines the current state of knowledge on this hypothesis. One hundred and ninety-nine studies are included in this systematic review based on criteria that they be written in English, use a biologically informed method, and be conducted on samples of humans. Results reveal that latent additive genetic influences, biological system functioning captured by biomarkers, polygenic risk scores, and neurobiological factors are commonly associated with exposure and response to CM and ACEs. The implication of these findings for the existing body of research on early life victimization and recommendations for future research and policy are discussed.

Postincident Interpersonal Difficulty Among Adolescent Victims of Violent Crime

Adolescents are exposed to high levels of violence in the United States. Exposure to violence at this point in the life course can have both short- and long-term consequences for young victims that include socioemotional distress and depression, substance abuse, and delinquency. Prior research indicates that positive, productive, and supportive reactions on the parts of those close to targets of violence attenuate feelings of distress and social anomie that many victims report. However, less attention has been devoted to the attributes of criminal violence that may stress the postincident interpersonal relationships of victims and their family members, friends, or peers. The disquieting effects of violence and bodily injury may influence how victims characterize their social connections in the wake of violent crime. This study uses data from the National Crime Victimization Survey (N = 1,652) to assess whether characteristics of violent acts and victims predict reports of postincident interpersonal difficulties made by violent crime victims aged 12 to 20. The findings are that more severe forms or levels of violence (e.g., robberies and sexual assaults) and reports of physical injuries are linked to perceptions of relationship difficulties with members of social networks by adolescent victims of violent crime. This study makes a contribution to our understanding of victimization by identifying levels of violence and injury as independent stressors on victims' perceptions of their relationships and as relevant components of how younger victims see themselves or are perceived by others. It also represents a direct test of whether attributes of violent acts undermine adolescents' perceptions of the quality of their relationships. The results of the study could also aid in the development of interventions that better address the needs of both young victims and their supporters.

The Interaction of Dopamine Genes and Financial Stressors to Predict Adulthood Intimate Partner Violence Perpetration

Three dopamine genes (DAT1, DRD2, and DRD4) have been associated with interpersonal delinquency, aggression, and violence when individuals experience adverse environmental exposures. Guided by the catalyst model of aggression, risk alleles identified in previous studies were hypothesized to be associated with intimate partner violence (IPV) perpetration in the presence of financial stressors, a possible environmental trigger. This hypothesis was tested using weighted, clustered logistic regression with data from the National Longitudinal Study of Adolescent to Adult Health. The direct effects DAT1, DRD2, and DRD4 on IPV perpetration, and the interaction of DAT1, DRD2, and DRD4 and financial stressors on IPV perpetration were assessed. Due to cell size, only White men and women were included in this analysis. Increasing number of financial stressors was associated with increased odds of IPV perpetration, regardless of DAT1, DRD2, and DRD4 alleles. As predicted, increasing number of financial stressors was more strongly associated with IPV perpetration among individuals with high-risk DAT1 alleles, than individuals with low-risk alleles. However, this relationship was inverted for DRD2. Although there was still a significant interaction between DRD2 and financial stressors, individuals with low-risk alleles had higher odds of IPV perpetration in the presence of financial stressors. A similar, nonsignificant relationship was found for DRD4. These findings indicate that these genes may interact differently with environmental exposures and types of violent behavior. In addition, the findings may, if replicated, suggest dopamine plays a different role in IPV perpetration compared with other forms of aggression and violence.

Antisocial Behavior and Victimization Over 2-Year Follow-Up in Subgroups of Childhood Arrestees

Not only are childhood onset offenders at high risk of becoming serious persistent offenders, they are also at high risk of becoming victimized themselves. Furthermore, studies in the general population suggest that a combined perpetrator-victim group can be distinguished from a perpetrator-only and a victim-only group on individual and family risk factors. The current study investigated the co-occurrence of offending and victimization among first-time arrestees and the 2-year predictive value of previously found clusters of dynamic risk factors of offending. Childhood first-time arrestees (N = 308; M_age = 10.3, SD = 1.45) were clustered into three groups based on dynamic risk factors of offending in the individual, peer, school, and family domains: a pervasive high, an externalizing intermediate, and a low problem group. Police records and self-report data on re-offending and victimization of these children were collected over a 2-year follow-up period. Compared with the low problem group, the prevalence of re-offending was higher in both the externalizing intermediate group and the pervasive high group. The pervasive high group was most likely to display co-occurring future antisocial behavior and victimization. These findings emphasize that attention should be paid to victimization in addition to future antisocial behavior, especially if additional internalizing and family problems are present. Furthermore, the differences in re-offending and victimization between subgroups of childhood onset offenders stress the need for specific interventions tailored to the risk profile of a child.

Examining the Association Between Personal Victimization in Adolescence and Intimate Partner Victimization in Adulthood

A large body of research has examined various issues related to repeat victimization, including potential risk factors and theoretical explanations. Despite the amount of studies dedicated to focusing on repeat victimization, there are some notable gaps in the literature. One particularly noteworthy omission in this research is whether there is a link between personal victimization in adolescence and intimate partner violence (IPV) victimization in adulthood. The current study sought to address this gap. To do so, data drawn from the National Longitudinal Study of Adolescent to Adult Health were analyzed. The results revealed a statistically significant and relatively consistent association between personal victimization in adolescence and IPV victimization in adulthood. This association was detected for both males and females, and it was detected even after controlling for low self-control (males and females) and being the perpetrator of IPV (males). We conclude by noting some of the implications of these findings, as well as limitations to the study that need to be addressed in the future.

The Causal Relationship between Childhood Adversity and Developmental Trajectories of Delinquency: A Consideration of Genetic and Environmental Confounds

An extensive line of research has found that children exposed to multiple forms of early life adversity are more likely to engage in high levels of delinquent behavior during adolescence. Several studies examining this association have used a range of multivariate statistical techniques capable of controlling for observable covariates. Fewer studies have used family-based research designs to additionally control for unobservable confounds, such as genetic and shared environmental influences, that may be associated with exposure to childhood adversity and delinquency. The current study analyzes self-report data on 2534 full-siblings (50% female) from the National Longitudinal Survey of Youth 1997 to conduct a sibling-comparison analysis to provide a rigorous test of the causal hypothesis that exposure to childhood adversity causes differences in developmental patterns of delinquent behavior. Results from multivariate latent growth curve models revealed that childhood adversity was associated with higher starting levels of delinquency during adolescence and slower rates of decline from adolescence to emerging adulthood. Results from multivariate sibling-comparison models, however, revealed that siblings exposed to higher levels of childhood adversity reported higher starting levels of delinquent behavior, but not slower declines over time, suggesting that childhood adversity may not be directly associated with long-term patterns of delinquent behavior after genetic and shared environmental factors are taken into account. Implications of these results for future research are discussed.

The Developmental Nature of the Victim-Offender Overlap

PURPOSE

It is well-established that victims and offenders are often the same people, a phenomenon known as the victim-offender overlap, but the developmental nature of this overlap remains uncertain. In this study, we drew from a developmental theoretical framework to test effects of genetics, individual characteristics, and routine-activity-based risks. Drawing from developmental literature, we additionally tested the effect of an accumulation of adverse childhood experiences (ACEs).

METHODS

Data came from the Environmental Risk (E-Risk) Study, a representative UK birth cohort of 2232 twins born in 1994-1995 and followed to age 18 (with 93% retention). Crime victimization and offending were assessed through self-reports at age 18 (but findings replicated using crime records). We used the classical twin study method to decompose variance in the victim-offender overlap into genetic and environmental components. We used logistic regression to test the effects of childhood risk factors.

RESULTS

In contrast to past twin studies, we found that environment (as well as genes) contributed to the victim-offender overlap. Our logistic regression results showed that childhood low self-control and childhood antisocial behavior nearly doubled the odds of becoming a victim-offender, compared to a victim-only or an offender-only. Each additional ACE increased the odds of becoming a victim-offender, compared to a victim-only or an offender-only, by approximately 12%, pointing to the importance of cumulative childhood adversity.

CONCLUSIONS

This study showed that the victim-offender overlap is, at least partially, developmental in nature and predictable from personal childhood characteristics and an accumulation of many adverse childhood experiences.

Genetics of aggressive behavior: An overview

The Research Domain Criteria (RDoC) address three types of aggression: frustrative non-reward, defensive aggression and offensive/proactive aggression. This review sought to present the evidence for genetic underpinnings of aggression and to determine to what degree prior studies have examined phenotypes that fit into the RDoC framework. Although the constructs of defensive and offensive aggression have been widely used in the animal genetics literature, the human literature is mostly agnostic with regard to all the RDoC constructs. We know from twin studies that about half the variance in behavior may be explained by genetic risk factors. This is true for both dimensional, trait-like, measures of aggression and categorical definitions of psychopathology. The non-shared environment seems to have a moderate influence with the effects of shared environment being unclear. Human molecular genetic studies of aggression are in an early stage. The most promising candidates are in the dopaminergic and serotonergic systems along with hormonal regulators. Genome-wide association studies have not yet achieved genome-wide significance, but current samples are too small to detect variants having the small effects one would expect for a complex disorder. The strongest molecular evidence for a genetic basis for aggression comes from animal models comparing aggressive and non-aggressive strains or documenting the effects of gene knockouts. Although we have learned much from these prior studies, future studies should improve the measurement of aggression by using a systematic method of measurement such as that proposed by the RDoC initiative.

Parental predictors of children's animal abuse: findings from a national and intergenerational sample

This study examines the intra- and intergenerational links between intimate partner violence (IPV) and animal abuse by analyzing a national, longitudinal, and multigenerational sample of 1,614 individuals collected by the National Youth Survey Family Study from 1990 to 2004. Using multilevel random-intercept regression modeling, parents' own history of animal abuse is predictive of their later involvement in IPV perpetration and victimization, net of important controls. In turn, parents' IPV violent perpetration (but not violent victimization) is predictive of their children's history of animal abuse-measured 14 years later. Intergenerational continuity of animal abuse, however, is not significant. Implications of these findings are discussed, as are the study's limitations, and future research directions.