Do etiological influences on aggression overlap with those on rule breaking? A meta-analysis

Investigating the impact of lumping heterogenous conduct problems: aggression and rule-breaking rely on distinct spontaneous brain activity

Accumulating evidence suggests that aggression and rule-breaking may have distinct origins. However, grouping these heterogeneous behaviors into a single dimension labelled Conduct Problems (CP) has become the norm rather than the exception. Yet, the neurobiological features that differentiate aggression and rule-breaking remain largely unexplored. Using a large sample of children and adolescents (n = 1360, 6-18 years old), we examined the common and specific brain activity between CP, aggression, and rule-breaking behaviors. Analyses were conducted using fMRI resting-state data from a 10-minute session to explore the correlations between low frequency fluctuations and both broad and fine-grained CP dimensions. The broad CP dimension was associated with deficits in the precentral gyrus, superior temporal gyrus, and tempo-parietal junction. However, only the superior temporal gyrus was shared between aggression and rule-breaking. Activity of the precentral gyrus was mainly associated with rule-breaking, and the temporo-parietal cortex with aggression. More importantly, voxel-wise analyses on fine-grained dimensions revealed additional specific effects that were initially obscured when using a broad CP dimension. Finally, we showed that the findings specific to aggression and rule-breaking may be related to distinct brain networks and mental functions, especially ventral attention/sensorimotor processes and default mode network/social cognitions, respectively. The current study highlights that aggression and rule-breaking may be related to distinct local and distributed neurobiological markers. Overall, using fine-grained dimensions may provide a clearer picture of the role of neurobiological correlates in CP and their invariance across measurement levels. We advocate for adopting a more thorough examination of the lumping/splitting effect across neuroimaging studies on CP.

The company you keep: The neglected role of affiliating with delinquent friends in the development of the cannabis-violence link

A growing body of research suggests a potential role of cannabis use on aggressive behaviors. In literature on adolescents, the lack of consideration of important confounders, such as adolescent's affiliation with delinquent peers, limits the possibility to determine whether there might be a direct or indirect link between cannabis use and aggression. Therefore, we sought to examine the effect of delinquent peers on the association between cannabis use and violence. We re-analyzed data from 850 ninth graders who were followed from mid-adolescence to early adulthood. Generalized Estimations Equations (GEE) were conducted to examine whether affiliation with delinquent peers may mediate the relationship between cannabis use and violence. Cross-Lagged Panel Models were also conducted to estimate the directionality of these relationships over time. We additionally tested whether similar relationships may be identifiable when examining rule-breaking behaviors and/or alcohol use. GEE models revealed that both cannabis use and affiliation with delinquent peers were statistically associated with aggressive behaviors. Cannabis use, alcohol use and delinquent peers also predicted rule-breaking behaviors. More precisely, cross-lagged models showed that affiliation with delinquent peers played a partially mediating role in the cannabis-aggression link, and that similar cross-lagged estimates were observed when examining rule-breaking behaviors instead of aggression. Our results indicate that cannabis use may be associated with aggression as well as rule-breaking behaviors, suggesting a broader effect on conduct problems. More importantly, our study highlights the non-negligible role of affiliating with delinquent peers during adolescence.

Using Dispositions to Understand Otherwise Intractable Causal Pathways to Psychological Problems During Childhood and Adolescence

Studies of the genetic and environmental factors that make children more or less likely to develop distressing and impairing psychological problems, and studies of the psychobiological pathways through which these causal factors operate, have the goal of improving our understanding of the basic nature of psychological problems to develop better methods of prevention and treatment. For this reason, we have long had our eye on the prize of discovering the causes and psychobiological mechanisms underlying each dimension of psychological problems. There are compelling reasons, however, to seek a different and more achievable prize to understand psychological problems. Dimensions of psychological problems are both far too heterogeneous and too highly correlated to line up with distinct causal pathways. In contrast, a small number of orthogonal cognitive and socioemotional dispositional dimensions are correlated with psychological problems in revealing cross-cutting patterns. Each of these dispositions shares its independent causal pathways with psychological problems and help us understand the complex shared and heterogeneous nature of their causal processes. I outline a strategy for understanding the causes and mechanisms of psychological problems using studies of independently measured dispositions.

Polygenic risk and hostile environments: Links to stable and dynamic antisocial behaviors across adolescence

Adverse environments are linked to elevated youth antisocial behavior. However, this relation is thought to depend, in part, on genetic susceptibility. The present study investigated whether polygenic risk for antisociality moderates relations between hostile environments and stable as well as dynamic antisocial behaviors across adolescence. We derived two antisocial-linked polygenic risk scores (PRS) (N = 721) based on previous genome-wide association studies. Forms of antisocial behavior (nonaggressive conduct problems, physical aggression, social aggression) and environmental hostility (harsh parenting and school violence) were assessed at age 13, 15, and 17 years. Relations to individual differences stable across adolescence (latent stability) vs. time-specific states (timepoint residual variance) of antisocial behavior were assessed via structural equation models. Higher antisocial PRS, harsh parenting, and school violence were linked to stable elevations in antisocial behaviors across adolescence. We identified a consistent polygenic-environment interaction suggestive of differential susceptibility in late adolescence. At age 17, harsher parenting was linked to higher social aggression in those with higher antisocial PRS, and lower social aggression in those with lower antisocial PRS. This suggests that genetics and environmental hostility relate to stable youth antisocial behaviors, and that genetic susceptibility moderates home environment-antisocial associations specifically in late adolescence.

Alcohol Use Disorder Polygenic Risk Scores and Trajectories of Early Adolescent Externalizing Behaviors: Examining the Role of Parenting and Family Conflict in the Racially/Ethnically Diverse ABCD Sample

This study examined the independent and interactive effects of alcohol use disorder genome-wide polygenic scores (AUD-PGS) and parenting and family conflict on early adolescent externalizing behaviors. Data were drawn from White (N = 6181, 46.9% female), Black/African American (N = 1784, 50.1% female), and Hispanic/Latinx (N = 2410, 48.0% female) youth from the adolescent brain cognitive development Study (ABCD). Parents reported on youth externalizing behaviors at baseline (T1, age 9/10), 1-year (T2, age 10/11) and 2-year (T3, age 11/12) assessments. Youth reported on parenting and family environment at T1 and provided saliva or blood samples for genotyping. Results from latent growth models indicated that in general externalizing behaviors decreased from T1 to T3. Across all groups, higher family conflict was associated with more externalizing behaviors at T1, and we did not find significant associations between parental monitoring and early adolescent externalizing behaviors. Parental acceptance was associated with lower externalizing behaviors among White and Hispanic youth, but not among Black youth. Results indicated no significant main effect of AUD-PGS nor interaction effect between AUD-PGS and family variables on early adolescent externalizing behaviors. Post hoc exploratory analysis uncovered an interaction between AUD-PGS and parental acceptance such that AUD-PGS was positively associated with externalizing rule-breaking behaviors among Hispanic youth, but only when parental acceptance was very low. Findings highlight the important role of family conflict and parental acceptance in externalizing behaviors among early adolescents, and emphasize the need to examine other developmental pathways underlying genetic risk for AUD across diverse populations.

The development of youth antisocial behavior across time and context: A systematic review and integration of person-centered and variable-centered research

BACKGROUND

Trajectories of youth antisocial behavior (ASB) are characterized by continuity and change. Although numerous longitudinal studies have examined ASB, findings from person-centered and variable-centered research have not yet been integrated. The present paper integrates findings across statistical methods for a more comprehensive understanding of the development of ASB. Neighborhood disadvantage is considered as a core moderator.

METHODS

The study protocol was registered in the PROSPERO database of systematic reviews (registration number CRD42021255820). The PsycINFO and PubMed databases were examined (September 2022) to identify longitudinal studies of youth aggression and/or rule-breaking. Results from person-centered and variable-centered studies were integrated via narrative synthesis, and a systematic quality assessment was conducted.

RESULTS

Of 8227 studies identified, 136 met inclusion criteria. Our review indicated that rule-breaking trajectories were largely distinguished by differences in rate of change (i.e., slope), whereas aggression trajectories differed more by baseline level (i.e., intercept), particularly in childhood. For adolescents in disadvantaged neighborhoods, however, aggression trajectories differed by both intercept and slope.

CONCLUSIONS

The respective importance of the intercept and slope differed across dimensions of ASB, developmental stage, and neighborhood residence. Neighborhood disadvantage was associated with trajectories of aggression, consistent with developmental theories emphasizing the role of person-environment interactions.

The Genetic, Environmental, and Cultural Forces Influencing Youth Antisocial Behavior Are Tightly Intertwined

The aggressive and rule-breaking behaviors that constitute youth antisocial behavior (ASB) are shaped by intertwined genetic, developmental, familial, spatial, temporal, cultural, interpersonal, and contextual influences operating across multiple levels of analysis. Genetic influences on ASB, for example, manifest in different ways during different developmental periods, and do so in part as a function of exposure to harsh parenting, delinquent peers, and disadvantaged neighborhoods. There is also clear evidence documenting societal effects, time-period effects, sex-assigned-at-birth effects, and cohort effects, all of which point to prominent (and possibly interconnected) cultural influences on ASB. In short, ASB is shaped by individuals' current and prior environmental experiences, genetic risks, and the time and place in which they live. This review seeks to illuminate already documented instances of interplay among the multilevel etiologic forces impinging on youth ASB, with the goal of facilitating additional research.

The origins of evil: From lesions to the functional architecture of the antisocial brain

In the past decades, a growing body of evidence has suggested that some individuals may exhibit antisocial behaviors following brain lesions. Recently, some authors have shown that lesions underpinning antisocial behaviors may disrupt a particular brain network during resting-state. However, it remains unknown whether these brain lesions may alter specific mental processes during tasks. Therefore, we conducted meta-analytic co-activation analyses on lesion masks of 17 individuals who acquired antisocial behaviors following their brain lesions. Each lesion mask was used as a seed of interest to examine their aberrant co-activation network using a database of 143 whole-brain neuroimaging studies on antisocial behaviors (n = 5,913 subjects). We aimed to map the lesion brain network that shows deficient activity in antisocial population against a null distribution derived from 655 control lesions. We further characterized the lesion-based meta-analytic network using term-based decoding (Neurosynth) as well as receptor/transporter density maps (JuSpace). We found that the lesion meta-analytic network included the amygdala, orbitofrontal cortex, ventro- and dorso-medial prefrontal cortex, fusiform face area, and supplementary motor area (SMA), which correlated mainly with emotional face processing and serotoninergic system (5-HT_1A and 5-HTT). We also investigated the heterogeneity in co-activation networks through data-driven methods and found that lesions could be grouped in four main networks, encompassing emotional face processing, general emotion processing, and reward processing. Our study shows that the heterogeneous brain lesions underpinning antisocial behaviors may disrupt specific mental processes, which further increases the risk for distinct antisocial symptoms. It also highlights the importance and complexity of studying brain lesions in relationship with antisocial behaviors.

Exploring the role of emotional and behavioral problems in a personality-targeted prevention program for substance use in adolescents and young adults with intellectual disability

BACKGROUND

Adolescents and young adults with a mild intellectual disability or borderline intellectual functioning (MID-BIF) are at risk for problematic substance use and are more likely to have emotional and behavioral problems than peers without MID-BIF. A personality-targeted prevention program called Take it Personal! effectively reduces substance use in adolescents and young adults with MID-BIF.

AIMS

The program's effectiveness was examined on its secondary goal: reducing emotional and behavioral problems. The potentially moderating role of these problems on the program's effectiveness with substance use was also explored.

METHODS AND PROCEDURES

Substance use and emotional and behavioral problems were compared between participants in Take it Personal! (n = 34) and those in the control condition (n = 32) in a quasi-experimental pre-posttest study with a three-month follow-up. Effectiveness and moderation were assessed with multilevel models.

OUTCOMES AND RESULTS

Take it Personal! seems to reduce rule breaking. There were no significant effects on anxiety, withdrawal, and aggression. None of the problem domains moderated the program's effectiveness on substance use frequency.

CONCLUSIONS AND IMPLICATIONS

Take it Personal! may effectively reduce rule breaking. Moreover, adolescent and young adults with different levels of emotional and behavioral problems benefit equally in terms of reduced substance use.

Reduced social distancing early in the COVID-19 pandemic is associated with antisocial behaviors in an online United States sample

Antisocial behaviors cause harm, directly or indirectly, to others' welfare. The novel coronavirus pandemic has increased the urgency of understanding a specific form of antisociality: behaviors that increase risk of disease transmission. Because disease transmission-linked behaviors tend to be interpreted and responded to differently than other antisocial behaviors, it is unclear whether general indices of antisociality predict contamination-relevant behaviors. In a pre-registered study using an online U.S. sample, we found that individuals reporting high levels of antisociality engage in fewer social distancing measures: they report leaving their homes more frequently (p = .024) and standing closer to others while outside (p < .001). These relationships were observed after controlling for sociodemographic variables, illness risk, and use of protective equipment. Independently, higher education and leaving home for work were also associated with reduced distancing behavior. Antisociality was not significantly associated with level of worry about the coronavirus. These findings suggest that more antisocial individuals may pose health risks to themselves and their community during the COVID-19 pandemic.

Reduced social distancing early in the COVID-19 pandemic is associated with antisocial behaviors in an online United States sample

Antisocial behaviors cause harm, directly or indirectly, to others' welfare. The novel coronavirus pandemic has increased the urgency of understanding a specific form of antisociality: behaviors that increase risk of disease transmission. Because disease transmission-linked behaviors tend to be interpreted and responded to differently than other antisocial behaviors, it is unclear whether general indices of antisociality predict contamination-relevant behaviors. In a pre-registered study using an online U.S. sample, we found that individuals reporting high levels of antisociality engage in fewer social distancing measures: they report leaving their homes more frequently (p = .024) and standing closer to others while outside (p < .001). These relationships were observed after controlling for sociodemographic variables, illness risk, and use of protective equipment. Independently, higher education and leaving home for work were also associated with reduced distancing behavior. Antisociality was not significantly associated with level of worry about the coronavirus. These findings suggest that more antisocial individuals may pose health risks to themselves and their community during the COVID-19 pandemic.

Punch-Drunk or Drunken Boxing? The Etiology of Alcohol-Related Physical Violence through Adolescence and Young Adulthood

BACKGROUND

Alcohol-related physical violence (ARPV) can be a causal consequence of alcohol consumption, but only for specific individuals (e.g., those predisposed to violence). Studies have not accounted for the shared etiology explaining comorbidity between alcohol use and violent behavior as a potential third-variable explanation of ARPV. The current study examined genetically-informed associations between ARPV, heavy alcohol use (HAU) and overall physical violence (OPV) in adolescence and young adulthood, by testing two proposed theories of ARPV processes (HAU causes ARPV, causal relationships depend upon OPV) and how overarching shared covariance may account for these associations.

METHODS

Using the twin and sibling subsample from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a series of biometric models tested hypotheses individually in adolescence and young adulthood. This included estimating bivariate Cholesky and direction-of-causality models, and trivariate Cholesky, independent pathway, and common pathway models.

RESULTS

HAU had a causal effect on ARPV in adolescence and young adulthood. This effect was not moderated by OPV at either developmental stage. A shared etiology or common latent factor did not explain associations between ARPV, OPV, and HAU, even though ARPV strongly covaried independently with HAU and with OPV. Finally, OPV also had a causal effect on ARPV in adolescence, and in young adulthood for adolescent-onset drinkers.

CONCLUSIONS

Causal theories of ARPV still hold when accounting for shared genetic and environmental variance. Further research on the exact role of violence (predispositions, environmental contexts) is required, as both phenotypes substantially (and separately) explain influences driving ARPV.

Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1887244.

Multiple developmental pathways underlying conduct problems: A multitrajectory framework

In the past decades, there has been an overemphasis of a descriptive/behavioral approach to study conduct disorder. In an equifinal perspective, we aimed to examine the developmental multitrajectory groups of psychological features (irritability, interpersonal callousness, hyperactivity/impulsivity, and depressive-anxiety symptoms) and their associations with conduct problems. In a population-based cohort (n = 1,309 participants followed from 5 months to 17 years old), latent-class growth analysis was performed for each psychological feature to identify a two-trajectory model (from ages 6 to 12 years). Based on parameter estimates of the two-trajectory models for each of the four psychological features, a parallel process growth mixture model identified eight significant developmental patterns that were subsequently compared with typically developing children. Furthermore, we observed that while interpersonal callousness conferred an increased risk for childhood and adolescence conduct problems, its co-occurrence with hyperactivity/impulsivity, irritability, and/or depressive-anxiety symptoms heightened the general risk, but also predicted distinct subtypes of conduct problems (i.e., aggressive and rule-breaking behaviors). Thus, by studying complex developmental combinations of psychological features, we observed qualitatively distinct pathways towards conduct problems. A multitrajectory framework of psychological features should be considered as a significant step towards unveiling the multiple etiological pathways leading to conduct disorder and its substantial clinical heterogeneity.

Cross-cultural effects of parent warmth and control on aggression and rule-breaking from ages 8 to 13

We investigated whether bidirectional associations between parental warmth and behavioral control and child aggression and rule-breaking behavior emerged in 12 cultural groups. Study participants included 1,298 children (M = 8.29 years, standard deviation [SD] = 0.66, 51% girls) from Shanghai, China (n = 121); Medellín, Colombia (n = 108); Naples (n = 100) and Rome (n = 103), Italy; Zarqa, Jordan (n = 114); Kisumu, Kenya (n = 100); Manila, Philippines (n = 120); Trollhättan/Vänersborg, Sweden (n = 101); Chiang Mai, Thailand (n = 120); and Durham, NC, United States (n = 111 White, n = 103 Black, n = 97 Latino) followed over 5 years (i.e., ages 8-13). Warmth and control were measured using the Parental Acceptance-Rejection/Control Questionnaire, child aggression and rule-breaking were measured using the Achenbach System of Empirically-Based Assessment. Multiple-group structural equation modeling was conducted. Associations between parent warmth and subsequent rule-breaking behavior were found to be more common across ontogeny and demonstrate greater variability across different cultures than associations between warmth and subsequent aggressive behavior. In contrast, the evocative effects of child aggressive behavior on subsequent parent warmth and behavioral control were more common, especially before age 10, than those of rule-breaking behavior. Considering the type of externalizing behavior, developmental time point, and cultural context is essential to understanding how parenting and child behavior reciprocally affect one another.

Callous-Unemotional Traits Moderate Genetic and Environmental Influences on Rule-Breaking and Aggression: Evidence for Gene × Trait Interaction

Previous behavioral genetic research in children has found that conduct problems in the presence of high CU traits are more heritable than conduct problems in the presence of low CU traits -- a gene × trait interaction. The current study replicates and extends this finding using a sample of adolescent twins from the Texas Twin Project, who were assessed for rule-breaking and aggression. We find evidence that genetic influences on CU traits contribute to genetic liability for both rule-breaking and aggressive behavior. CU traits moderate genetic influences on aggressive behavior, such that the heritability of aggression is higher among youth with high levels of CU traits. However, we do not find evidence that CU traits moderate genetic influences on rule-breaking behavior. The continuum of callous-unemotionality and the aggression versus rule-breaking distinction continues to be meaningful and intersecting methods for characterizing heterogeneity in the etiology of antisocial behavior.

Early adolescent aggression predicts antisocial personality disorder in young adults: a population-based study

Modestly prevalent in the general population (~ 4%), but highly prevalent in prison populations (> 40%), the diagnosis of antisocial personality disorder (ASPD) involves aggression as one of several possible criteria. Using multiple informants, we aimed to determine if general aggression, as well as direct and indirect subtypes, assessed in early adolescence (ages 12, 14) predict young adulthood ASPD in a population-based sample. Using data from a Finnish population-based longitudinal twin cohort study with psychiatric interviews available at age 22 (N = 1347), we obtained DSM-IV-based ASPD diagnoses. Aggression measures from ages 12 (parental and teacher ratings) and 14 (teacher, self, and co-twin ratings) were used to calculate odds ratios (OR) of ASPD from logistic regression models and the area under the curve (AUC) from receiver operating characteristic curve analysis. Analyses were adjusted for sex, age, and family structure. All informants' aggression ratings were significant (p < 0.05) predictors of ASPD (OR range 1.3-1.8; AUC range 0.65-0.72). Correlations between informants ranged from 0.13 to 0.33. Models including two or more aggression ratings, particularly age 14 teacher and self ratings, more accurately predicted ASPD (AUC: 0.80; 95% confidence interval 0.73-0.87). Direct aggression rated by all informants significantly predicted ASPD (OR range 1.4-1.9), whereas only self-rated indirect aggression was significantly associated with ASPD (OR = 1.4). Across different informants, general and direct aggression at ages 12 and 14 predicted ASPD in a population-based sample. Psychiatric, social, and parenting interventions for ASPD prevention should focus on children and adolescents with high aggression levels, with an aim to gather information from multiple informants.

Risky business! Behavioral bias and motivational salience of rule-violations in children with conduct disorder

Conduct disorder is characterized by both habitual aggression as well as non-aggressive rule-breaking behavior. While a large body of research has focused on aggressive behavior to date, the subtype of non-aggressive rule-breaking behavior is poorly understood. The current study represents a first attempt to directly assess decision biases toward rule-breaking behavior, their motivational salience, and the association with interpersonal factors in conduct disorder. Participants (n = 20 children with conduct disorder and n = 20 healthy controls) played a video game with the goal to deliver a hot pizza by bicycle to a marked location on a two-dimensional city map. In each trial, participants decided whether to use the regular route (streets) or opt for a potential shortcut that was either permitted (bicycle lane) or prohibited (park). The efficiency of the shortcut was parametrically varied to assess individual decision functions. Consistent with our hypotheses, group differences emerged only when taking a shortcut represented a rule violation (park condition), with the conduct disorder group committing significantly more rule violations than controls. Furthermore, conduct disorder children showed a substantial frequency of rule violations even in the absence of shortcut related gains, indicating a pronounced insensitivity towards sanctions. Importantly, this tendency was associated with self-reported impulsivity and rule violations in real life.

Children Sleep and Antisocial Behavior: Differential Association of Sleep with Aggression and Rule-Breaking

There is a strong relationship between sleep and behavioral problems. These findings are often interpreted via environmental explanations, such that poor sleep directly exacerbates or causes symptoms of aggression and behavior problems. However, there are other possible explanations, such that the genes predicting poor sleep also predict aggression or rule-breaking. The current study sought to elucidate the origin of this relationship. The sample was composed of 1030 twin pairs (426 monozygotic and 604 dizygotic). The sample was 51.3% male with a mean age of 8.06 years (range 6-11.96; SD = 1.45). Aggression, rule-breaking and sleep were assessed through the Child Behavior Checklist (CBCL). We fitted bivariate Cholesky genetic models to the data, decomposing the variance within, and the covariance among, aggression, rule-breaking, and sleep functioning into their genetic and environmental components. Genetic correlations between all sleep variables and aggression were significant and moderate to large in magnitude, but mostly small and non-significant between sleep and rule-breaking. We did not find evidence of a causal or environmental relationship between the majority of sleep variables and aggression, but rather clear evidence of genetic pleiotropy. However, the pattern of associations between rule-breaking and sleep measures was less consistent. Aggression and rule-breaking appear to be differentially associated with sleep.

Conduct disorder in adolescent females: current state of research and study design of the FemNAT-CD consortium

Conduct disorder (CD) is a common and highly impairing psychiatric disorder of childhood and adolescence that frequently leads to poor physical and mental health outcomes in adulthood. The prevalence of CD is substantially higher in males than females, and partly due to this, most research on this condition has used all-male or predominantly male samples. Although the number of females exhibiting CD has increased in recent decades, the majority of studies on neurobiological measures, neurocognitive phenotypes, and treatments for CD have focused on male subjects only, despite strong evidence for sex differences in the aetiology and neurobiology of CD. Here, we selectively review the existing literature on CD and related phenotypes in females, focusing in particular on sex differences in CD symptoms, patterns of psychiatric comorbidity, and callous-unemotional personality traits. We also consider studies investigating the neurobiology of CD in females, with a focus on studies using genetic, structural and functional neuroimaging, psychophysiological, and neuroendocrinological methods. We end the article by providing an overview of the study design of the FemNAT-CD consortium, an interdisciplinary, multi-level and multi-site study that explicitly focuses on CD in females, but which is also investigating sex differences in the causes, developmental course, and neurobiological correlates of CD.

Sex Differences in the Genetic and Environmental Influences on Self-Reported Non-aggressive and Aggressive Conduct Disorder Symptoms in Early and Middle Adolescence

Decades of research into the etiology of conduct disorder (CD) has yet to yield a consensus on the existence of sex differences in underlying genetic and environmental influences. This may be partly due to the failure of many previous studies to make a distinction between non-aggressive and aggressive CD symptoms or test for potential developmental changes in sex differences in the etiology of conduct problems. To address these gaps, we fit a series of univariate and bivariate biometric sex-difference models to self-reported non-aggressive and aggressive CD symptoms in a community-based sample of twins (N = 1548, ages 9-17 year), grouped into ages 9-13 and 14-17 years. Relative model fit was evaluated using the Bayesian Information Criterion (BIC), which favors parsimony, and by Chi square difference tests. The univariate sex-scalar model provided the best fit to the data for both non-aggressive and aggressive CD symptoms at ages 9-13 and 14-17 years. Thus, the same genetic and environmental factors influenced CD symptoms in both sexes, but the total variability was lower in females than males. At both ages, the heritability of non-aggressive CD symptoms was lower than heritability of aggressive CD symptoms, and shared environmental effects were only observed for non-aggressive CD symptoms. However, estimates for genetic and environmental factors could be not be constrained to be equal across age groups for either CD subtype, suggesting substantive developmental changes in the relative influence of genetic and environmental factors on individual differences in CD symptoms. For both subtypes, the heritability was larger, and shared environmental effect smaller, in the older age group than the younger age group. A bivariate quantitative sex differences model provided the best fit to the data at ages 9-13 years. Covariation between non-aggressive and aggressive CD symptoms was due to overlapping shared and non-shared environmental factors in males and females but the overall covariation was greater in males than females. In contrast, at ages 14-17 years, the sex-scalar bivariate model provided the best fit to the data, and covariation between non-aggressive and aggressive CD symptoms was due to overlapping genetic and non-shared environmental factors. Thus, the etiology of self-reported conduct disorder varied substantially by symptom type and age. However, quantitative sex differences were only apparent when the covariation between the two subtypes was considered.

Childhood aggression: A synthesis of reviews and meta-analyses to reveal patterns and opportunities for prevention and intervention strategies

This study provides a synthesis of meta-analyses and systematic reviews on non-pharmacological treatments for childhood aggression. Treatments referred to universal prevention, selective prevention, indicated prevention, or intervention (Mrazek and Haggerty, 1994). Seventy-two meta-analyses and systematic reviews met the inclusion criteria. We describe their characteristics, effect sizes across types of treatments, and the effects of various moderators. For universal and selective prevention, effects were mostly absent or small; for indicated prevention and interventions, effects were mostly small or medium. Only two moderators had a positive effect on treatment effectiveness, namely pre-test levels of aggression and parental involvement. These results identified similarities between indicated prevention and intervention treatments, on the one hand, and universal prevention and selective prevention, on the other. Our findings suggest that research distinguishing between targets of treatments (i.e., factors associated with childhood aggression vs. present aggressive behaviors) would be promising. Moreover, to further increase effectiveness of treatments for childhood aggression, individual differences warrant scientific attention.

Assessing the interplay between multigenic and environmental influences on adolescent to adult pathways of antisocial behaviors

The current investigation utilized a developmental psychopathology approach to test the hypothesis that multigenic (i.e., dopaminergic and serotonergic genes) and multienvironmental factors interactively contribute to developmental pathways of antisocial behavior (ASB). A sample of 8,834 Caucasian individuals from the National Longitudinal Study of Adolescent to Adult Health (Add Health) were used to (a) examine the developmental pathways of ASB from age 13 to 32 using growth mixture modeling, (b) compute weighted multigenic risk scores (Add Health MRS) for ASB from six well-characterized polymorphisms in dopamine and serotonin genes, and (c) test the interaction between the Add Health MRS and a measures of support (incorporating indicators of both positive and negative support from parents and schools). Four pathways of adolescent to adult ASB emerged from the growth mixture models: low, adolescence-peaked, high decline, and persistent. Add Health MRS predicted the persistent ASB pathway, but not other ASB pathways. Males with high Add Health MRS, but not low MRS, had significantly greater odds of being in the adolescence-peaked pathway relative to the low pathway at low levels of school connectedness. Nonfamilial environmental influences during adolescence may have a cumulative impact on the development of ASB, particularly among males with greater underlying genetic risks.

Antisocial Behavior and Interpersonal Values in High School Students

This article analyzes the characteristics of antisocial behavior and interpersonal values of high school students (Compulsory Secondary Education) (CSE), the profile of students with high levels of antisocial behavior with regard to interpersonal values, and possible protection from antisocial behavior that interpersonal values could provide. The Interpersonal Values Questionnaire was used to assess interpersonal values, and the Antisocial-Delinquent Behaviors Questionnaire was employed to assess antisocial behaviors. The sample was made up of 885 CSE students aged 14–17. The results revealed a greater prevalence of antisocial behaviors among males and fourth-year CSE students. Moreover, antisocial behaviors were more frequent among participants with high scores in Stimulation, Recognition, Independence, and Leadership and low scores in Conformity and Benevolence. Lastly, logistic regression analyses showed that low scores in Conformity and Benevolence and high scores in Independence predicted high scores in antisocial behavior. The possibility of identifying certain interpersonal values which could positively or negatively affect the appearance of antisocial behavior during adolescence is discussed.

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.

Developmental changes in genetic and environmental influences on rule-breaking and aggression: age and pubertal development

BACKGROUND

Antisocial behavior (ASB) can be meaningfully divided into nonaggressive rule-breaking versus aggressive dimensions, which differ in developmental course and etiology. Previous research has found that genetic influences on rule-breaking, but not aggression, increase from late childhood to mid-adolescence. This study tested the extent to which the developmental increase in genetic influence on rule-breaking was associated with pubertal development compared to chronological age.

METHOD

Child and adolescent twins (n = 1,031), ranging in age from 8 to 20 years (M age = 13.5 years), were recruited from public schools as part of the Texas Twin Project. Participants reported on their pubertal development using the Pubertal Development Scale and on their involvement in ASB on items from the Child Behavior Checklist. Measurement invariance of ASB subtypes across age groups (≤12 years vs. >12 years old) was tested using confirmatory factor analyses. Quantitative genetic modeling was used to test whether the genetic and environmental influences on aggression and rule-breaking were moderated by age, pubertal status, or both.

RESULTS

Quantitative genetic modeling indicated that genetic influences specific to rule-breaking increased as a function of pubertal development controlling for age (a gene × puberty interaction), but did not vary as a function of age controlling for pubertal status. There were no developmental differences in the genetic etiology of aggression. Family-level environmental influences common to aggression and rule-breaking decreased with age, further contributing to the differentiation between these subtypes of ASB from childhood to adolescence.

CONCLUSIONS

Future research should discriminate between alternative possible mechanisms underlying gene × puberty interactions on rule-breaking forms of antisocial behavior, including possible effects of pubertal hormones on gene expression.

Investigating genetic and environmental contributions to adolescent externalizing behavior in a collectivistic culture: a multi-informant twin study

BACKGROUND

Little is known about the etiology of adolescents' externalizing behavior (Ext) in collectivistic cultures. We aimed to fill this gap by investigating the genetic and environmental influences on Ext in Chinese adolescents. The etiological heterogeneity of aggression (AGG) and rule breaking (RB) was also examined.

METHOD

The study sample included 908 pairs of same-sex twins aged from 10 to 18 years (mean = 13.53 years, s.d. = 2.26). Adolescents' Ext were assessed with the Achenbach System of Empirically Based Assessment including Child Behavior Checklist, Teacher Report Form, and Youth Self-Report.

RESULTS

Univariate genetic analyses showed that genetic influences on all measures were moderate ranging from 34% to 50%, non-shared environmental effects ranged from 23% to 52%, and shared environmental effects were significant in parent- and teacher-reported measures ranging from 29% to 43%. Bivariate genetic analyses indicated that AGG and RB shared large genetic influences (r g = 0.64-0.79) but moderate non-shared environmental factors (r e = 0.34-0.52).

CONCLUSIONS

Chinese adolescents' Ext was moderately influenced by genetic factors. AGG and RB had moderate independent genetic and non-shared environmental influences, and thus constitute etiologically distinct dimensions within Ext in Chinese adolescents. The heritability of AGG, in particular, was smaller in Chinese adolescents than suggested by previous data obtained on Western peers. This study suggests that the collectivistic cultural values and Confucianism philosophy may attenuate genetic potential in Ext, especially AGG.

The etiology of the association between child antisocial behavior and maternal negativity varies across aggressive and non-aggressive rule-breaking forms of antisocial behavior

There is a robust association between negative parenting and child antisocial behavior problems. However, the etiology of this association remains unclear. Extant literature has reported strikingly different conclusions across studies, with some highlighting genetic mediation and others highlighting environmental mediation. One possible reason for these discrepancies across studies may be the failure to differentiate between aggressive and non-aggressive (rule-breaking) dimensions of childhood antisocial behavior, given their notably different etiologies and developmental trajectories (Burt 2012). The current study sought to examine the phenotypic and etiologic associations of maternal negativity with aggressive and rule-breaking antisocial behavior, respectively. Participants included 824 mothers and their twin children between the ages of 6 and 10. Our results highlighted clear etiologic distinctions in the associations of aggression and rule-breaking with maternal negativity. Aggression was associated with maternal negativity via both genetic and environmental factors, whereas the association between non-aggressive rule-breaking and maternal negativity was entirely environmental in origin. These findings provide additional support for the presence of meaningful distinctions between aggressive and non-aggressive forms of antisocial behavior, and highlight the complex relationship between parenting and child outcome.

The Expression of Genetic Risk for Aggressive and Non-aggressive Antisocial Behavior is Moderated by Peer Group Norms

Numerous studies have shown that aggressive and non-aggressive antisocial behaviors are important precursors of later adjustment problems. There is also strong empirical evidence that both types of antisocial behavior are partially influenced by genetic factors. However, despite its important theoretical and practical implications, no study has examined the question whether environmental factors differentially moderate the expression of genetic influences on the two types of antisocial behavior. Using a genetically informed design based on 266 monozygotic and dizygotic twin pairs, this study examined whether the expression of genetic risk for aggressive and non-aggressive antisocial behavior varies depending on the peer group's injunctive norms (i.e., the degree of acceptability) of each type of antisocial behavior. Self-reported aggressive and non-aggressive antisocial behavior and classroom-based sociometric nominations were collected when participants were 10 years old. Multivariate genetic analyses revealed some common genetic factors influencing both types of antisocial behavior (i.e., general antisocial behavior) as well as genetic influences specific to non-aggressive antisocial behavior. However, genetic influences on general antisocial behavior, as well as specific genetic influences on non-aggressive antisocial behavior, vary depending on the injunctive classroom norms regarding these behaviors. These findings speak to the power of peer group norms in shaping aggressive and non-aggressive antisocial behavior. They also contribute further to understanding the distinctive development of both types of antisocial behavior. Finally, they may have important implications for prevention purposes.