Identifying Psychological Pathways to Polyvictimization: Evidence from a Longitudinal Cohort Study of Twins from the United Kingdom

Causal and common risk pathways linking childhood maltreatment to later intimate partner violence victimization

Childhood maltreatment and intimate partner violence (IPV) victimization are major psychiatric risk factors. Maltreatment substantially increases the likelihood of subsequent IPV victimization, but what drives this association is poorly understood. We analyzed retrospective self-reports of maltreatment and IPV victimization in 12,794 participants (58% women, 42% men) from the Twins Early Development Study at ages 21 and 26 using quantitative genetic methods. We estimated the etiological influences common to maltreatment and IPV, and the effect of maltreatment on IPV beyond such common influences. Participants who reported childhood maltreatment ( ~ 7% of the sample) were 3 times more likely than their peers to also report IPV victimization at age 21, 4 times more likely at 26. The association between maltreatment and IPV was mostly due to environmental influences shared by co-twins (42-43%) and genetic influences (30-33%), as well as nonshared environmental influences (25-27%). The association between maltreatment and IPV was similar for women and men, but its etiology partly differed by sex. Maltreatment had a moderate effect on IPV in phenotypic models (β = 0.25-0.30), decreasing to a small-to-moderate range in causally informative models accounting for their common etiology (β = 0.15-0.21). Risk factors common to maltreatment and IPV victimization are largely familial in origin, environmental and genetic. Even considering common risk factors, experiencing maltreatment may be causally related to subsequent IPV victimization. Interventions promoting safe intimate relationships among young adults exposed to maltreatment are warranted and should address family-level environmental risk and individual-level risk shaped by genetics.

Do polygenic indices capture "direct" effects on child externalizing behavior problems? Within-family analyses in two longitudinal birth cohorts

Failures of self-control can manifest as externalizing behaviors (e.g., aggression, rule-breaking) that have far-reaching negative consequences. Researchers have long been interested in measuring children's genetic risk for externalizing behaviors to inform efforts at early identification and intervention. Drawing on data from the Environmental Risk Longitudinal Twin Study (N = 862 twins) and the Millennium Cohort Study (N = 2,824 parent-child trios), two longitudinal cohorts from the UK, we leveraged molecular genetic data and within-family designs to test for genetic associations with externalizing behavior that are not affected by common sources of environmental influence. We found that a polygenic index (PGI) calculated from genetic variants discovered in previous studies of self-controlled behavior in adults captures direct genetic effects on externalizing problems in children and adolescents when evaluated with rigorous within-family designs (β's = 0.13-0.19 across development). The externalizing behavior PGI can usefully augment psychological studies of the development of self-control.

A Systematic Review of Conceptualizations and Operationalizations of Youth Polyvictimization

Violence against youth is a global issue impacting millions each year. Increasingly, research has focused on studying those impacted by multiple forms of violence, or polyvictims. Evidence strongly suggests that polyvictimized youth tend to have worse physical and mental health outcomes than those who have experienced single forms of violence. Moreover, minoritized youth (i.e., racial and/or sexual minority youth, youth with disabilities) are more likely to experience polyvictimization, making this a social justice and equity concern. To date, there is no universal consensus on what exactly constitutes polyvictimization. This systematic review aims to examine the ways in which polyvictimization is being studied to inform both research and practice. As such, relevant databases were searched to amass the extant literature related to youth polyvictimization internationally. Empirical studies published since 2006 that focused on youth (under age 18) polyvictimization were included. After the review process, 264 studies met eligibility criteria, however 55 studies employed person-centered/finite mixture analyses and were removed for a separate review, resulting in 209 featured in the current systematic review. Results demonstrate that researchers are defining and operationalizing polyvictimization in different ways: (a) using individual victimization event counts; (b) employing domain-based counts; and (c) taking a "highest-victimized" percentage of their sample. The most used measurement tool was the Juvenile Victimization Questionnaire, though other validated tools and researcher-constructed questions were frequently utilized. Research on polyvictimization is burgeoning worldwide; however, this research is being conducted in disparate ways, making it difficult to compare findings and further advance the field.

Causal and common risk pathways linking childhood maltreatment to later intimate partner violence victimization

Childhood maltreatment and intimate partner violence (IPV) victimization are major psychiatric risk factors. Maltreatment substantially increases the likelihood of subsequent IPV victimization, but what drives this association is poorly understood. We analyzed retrospective self-reports of maltreatment and IPV in 12794 participants (58% women, 42% men) from the Twins Early Development Study at ages 21 and 26 using quantitative genetic methods. We estimated the etiological influences common to maltreatment and IPV, and the direct causal effect of maltreatment on IPV beyond such common influences. Participants exposed to maltreatment (~7% of the sample) were 3 times more likely to experience IPV victimization than their peers at age 21, 4 times more likely at 26. The association between maltreatment and IPV was mostly due to environmental influences shared by co-twins (42-43%) and genetic influences (30-33%). The association between maltreatment and IPV was similar for women and men, but its etiology partly differed by sex. Maltreatment had a moderate-to-large effect on IPV in phenotypic models (β = 0.23-0.34), decreasing to a small-to-moderate range in causal models accounting for their common etiology (β = 0.15-0.21). Risk factors common to maltreatment and IPV victimization are largely familial in origin, environmental and genetic. Even considering common risk factors, experiencing maltreatment is causally related to subsequent IPV victimization. Interventions promoting safe intimate relationships among young adults exposed to maltreatment are warranted and should address family-level environmental risk and individual-level risk shaped by genetics.

Evolution, the Cognitive Sciences, and the Science of Victimization

Despite clear aversion to such labels, one of the most impactful criminological theories is rooted in cognitive science. Gottfredson and Hirschi's general theory has been repeatedly tested, replicated relatively well, and has since reached beyond its original scope to explain other important outcomes like victimization. However, the work never viewed itself as part of a larger scientific landscape and resisted the incursion of neuroscience, cognitive science, and evolutionary theory from the start. This missed opportunity contributes to some of the theory's shortcomings. We begin by considering relevant literatures that were originally excluded and then conduct a new analysis examining the cognitive underpinnings of victimization in a high-risk sample of adolescents. We used the Future of Families and Child Wellbeing Study (n = 3,444; 48% female; 49% Black, 25% Hispanic) which contained sound measures of self-control and intelligence, as well as four types of adolescent victimization. Self-control was robustly associated with all forms of victimization, whereas intelligence had generally no detectable effect. We discuss how these findings fit into a broader understanding about self-control and victimization.

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.

Why twin studies are important for health span science research: the case of maltreatment of aging adults

Average life expectancies have lengthened across human history. As a result, there is an increased need to care for a greater number of individuals experiencing common age-related declines in health. This has helped to spur a rapidly increasing focus on understanding "health span", the portion of the life-course spent functionally healthy. Yet to penetrate the science of health span, however, is a topic which seems fundamental to the ability to age in functional and healthy ways, and has received considerable attention in other fields. As more of the population ages, the risk of exposure to abuse and neglect among older citizens not only rises, but can manifest as both cause and effect of declining health span. Among our goals here is to make a case for including this subject among the other central components of health span science. In so doing, we also outline reasons why quantitative genetic designs using samples of twins can be a versatile tool for improving causal inference when studying maltreatment among older persons specifically, but also on a range of other health span topics in general.

Stress-related hippocampus activation mediates the association between polyvictimization and trait anxiety in adolescents

Early life stress exposures are associated with adverse health outcomes and heightened anxiety symptoms in adolescents. Stress-sensitive brain regions like the hippocampus and amygdala are particularly impacted by early life adversities and are also implicated in the development of anxiety disorders. However, to date, no studies have specifically examined the neural correlates of polyvictimization (exposure to multiple categories of victimization) or the contribution of stress-sensitive neural nodes to polyvictimization's impact on mental health. To elucidate these relationships, the current study analyzed associations between polyvictimization, hippocampal and amygdalar activation during an acute stress task and trait anxiety in a sample of 80 children and adolescents aged 9-16 years (33 female participants). Results showed that polyvictimization was associated with higher trait anxiety as well as greater stress-related right hippocampus activation, and this greater hippocampal activity predicted heightened trait anxiety. Robust mediation analyses revealed that stress-related right hippocampus activation partially mediated the relationship between polyvictimization and trait anxiety. Our results expand upon the existing polyvictimization literature by suggesting a possible neurobiological pathway through which polyvictimization is connected to the etiology of mental illness.