The genetic underpinnings of callous-unemotional traits: A systematic research review

Objective Linguistic Markers Associated with Callous-Unemotional Traits in Early Childhood

BACKGROUND

Callous-unemotional (CU) traits are associated with interpersonal difficulties and risk for severe conduct problems (CP). The ability to communicate thoughts and feelings is critical to social success, with language a promising treatment target. However, no prior studies have examined objective linguistic correlates of childhood CU traits in early childhood, which could give insight into underlying risk mechanisms and novel target treatments.

METHODS

We computed lexical (positive emotion, sad, and anger words) and conversational (interruptions and speech rate) markers produced by 131 children aged 5-6 years (M = 5.98; SD = 0.54, 58.8% female) and their parents while narrating wordless storybooks during two online visits separated by 6-8 weeks (M = 6.56, SD = 1.11; two books, order counterbalanced). Audio recordings were diarized, time-aligned, and orthographically transcribed using WebTrans. Conversational markers were calculated using R and word frequencies were calculated using Linguistic Inquiry and Word Count (LIWC) software. We examined links between child CU traits and linguistic markers, and explored whether relationships were moderated by child sex.

RESULTS

Higher CU traits were associated with fewer positive emotion words produced by parents and children. Higher CU traits were also associated with greater concordance in the degree of interruptions and expression of anger emotion words by parents and children.

CONCLUSIONS

Results suggest that objective linguistic correlates of CU traits are detectable during early childhood, which could inform adjunctive treatment modules that improve outcomes by precisely tracking and targeting subtle communication patterns.

Measurement invariance of the inventory of Callous‑Unemotional traits in different age groups from preschool age to late adolescence in Germany

BACKGROUND

Callous-unemotional traits are associated with the development of severe behavior problems, delinquency, and psychopathy. Previous studies have repeatedly shown that CU traits may be present as early as preschool age, and they have consistently used the Inventory of Callous-Unemotional Traits (ICU) to assess CU traits in children and adolescents. A three-factor structure for the ICU has been widely endorsed.

METHOD

The aim of our study is to compare the three-factor structure of the ICU in different age groups (preschool, middle childhood, early, and late adolescence) and to test for measurement invariance in a German sample of N = 2368 children and adolescents (M = 11.76 years; SD = 3.72).

RESULTS

The results of our study indicate configural measurement invariance, suggesting that the ICU has the same structure in all age groups but with different meanings, parameters, and mean values in the groups.

CONCLUSION

Accordingly, the ICU cannot be applied in the same way to children and adolescents of different age groups, which emphasizes the need for a more differentiated assessment.

Reciprocal Effects Between Negative Parenting and Children's Callous-Unemotional Traits From Mid to Late Childhood

OBJECTIVE

The role of negative parenting in the development of callous-unemotional (CU) traits remains unclear. Both negative parenting and CU traits are influenced by genetic and environmental factors. The authors used genetically informed longitudinal cross-lagged models to examine the extent to which reciprocal effects between negative parenting and children's CU traits in mid-to-late childhood are genetic versus environmental in origin.

METHODS

In 9,260 twin pairs from the Twins Early Development Study, the authors estimated cross-lagged effects between negative parenting (discipline and feelings) and children's CU traits in mid (ages 7-9) and late (ages 9-12) childhood.

RESULTS

CU traits were strongly heritable and stable. Stability was explained largely by genetic factors. The influence of negative parenting on the development of CU traits was small and driven mostly by genetic and shared environmental factors. In mid childhood, the influence of children's CU traits on subsequent negative parenting (i.e., evoked by children's CU traits) was also small and mostly genetic in origin. In late childhood, CU traits showed no effects on negative parental discipline and small effects on negative parental feelings, which reflected mostly shared environmental factors.

CONCLUSIONS

In mid-to-late childhood, genetic factors strongly influenced the development of CU traits, whereas environmental effects of negative parenting were small. Negative parenting was also relatively unaffected by CU traits. The small reciprocal effects originated mostly from genetic and shared environmental factors. Therefore, repeated intensive interventions addressing multiple risk factors rather than negative parenting alone may be best positioned to support families of children with CU traits across development.

A systematic review of callous-unemotional traits and attachment in children and adolescents

METHODS

The systematic review and meta-analysis included 17 research articles from 1994 to 2022. Results were summarized by developmental periods.

RESULTS

Attachment insecurity was associated with CU traits across development (r = .17). This association was marginally stronger for high-risk samples (e.g., clinical, justice) and for continuous attachment measures versus coding schemes. From early to middle childhood, attachment disorganization was associated with CU traits (r = .17).

IMPLICATIONS

Research on attachment and CU traits in childhood is still in its infancy. Changes in attachment measures from childhood to adolescence make developmental comparisons difficult. Results suggest attachment as a potential developmental mechanism for youth with CU traits, however, the area requires more research.

Newborn Brain Function and Early Emerging Callous-Unemotional Traits

Importance

Children with high callous-unemotional traits are more likely to develop severe and persistent conduct problems; however, the newborn neurobiology underlying early callous-unemotional traits remains unknown. Understanding the neural mechanisms that precede the development of callous-unemotional traits could help identify at-risk children and encourage development of novel treatments.

Objective

To determine whether newborn brain function is associated with early-emerging empathy, prosociality, and callous-unemotional traits.

Design, Setting, and Participants

In this prospective, longitudinal cohort study, pregnant women were recruited from obstetric clinics in St Louis, Missouri, from September 1, 2017, to February 28, 2020, with longitudinal data collected until March 20, 2023. Mothers were recruited during pregnancy. Newborns underwent brain magnetic resonance imaging shortly after birth. Mothers completed longitudinal follow-up when the children were aged 1, 2, and 3 years.

Exposures

The sample was enriched for exposure to socioeconomic disadvantage.

Main Outcome and Measure

Functional connectivity between hypothesized brain regions was assessed using newborn-specific networks and voxel-based connectivity analyses. Children's callous-unemotional traits were measured using the Inventory of Callous-Unemotional Traits. Empathy and prosociality were assessed using the Infant and Toddler Socio-Emotional Assessment.

Results

A total of 283 children (mean [SD] gestational age, 38 [2] weeks; 159 male [56.2%]; 2 Asian [0.7%], 171 Black [60%], 7 Hispanic or Latino [2.5%], 106 White [38%], 4 other racial or ethnic group [1.4%]) were included in the analysis. Stronger newborn functional connectivity between the cingulo-opercular network (CO) and medial prefrontal cortex (mPFC) was associated with higher callous-unemotional traits at age 3 years (β = 0.31; 95% CI, 0.17-0.41; P < .001). Results persisted when accounting for parental callous-unemotional traits and child externalizing symptoms. Stronger newborn CO-mPFC connectivity was also associated with lower empathy and lower prosociality at ages 1, 2, and 3 years using multilevel models (β = -0.12; 95% CI, -0.21 to -0.04; P = .004 and β = -0.20; 95% CI, -0.30 to -0.10; P < .001, respectively).

Conclusions and Relevance

Newborn functional connectivity was associated with early-emerging empathy, prosociality, and callous-unemotional traits, even when accounting for parental callous-unemotional traits and child externalizing symptoms. Understanding the neurobiological underpinnings of empathy, prosociality, and callous-unemotional traits at the earliest developmental point may help early risk stratification and novel intervention development.

Parenting Characteristics and Callous-Unemotional Traits in Children Aged 0-6 Years: A Systematic Narrative Review

There has been a growing interest in research examining the relationship between parenting and child callous-unemotional (CU) traits, particularly in early childhood. This study reviewed evidence from studies that investigated the relationship between parenting characteristics (e.g., caregiving beliefs, attitudes, behaviour or quality, or parental mental health) and callous-unemotional traits in children aged 0 to 6 years. A systematic search conducted according to PRISMA guidelines yielded 27 peer-reviewed articles. Analysis of the included articles suggested that there was strong evidence to support links between child CU traits and parenting characteristics (particularly, parental feelings about their child, warm parenting, and harsh/ inconsistent parenting). Taken together, the results of this review demonstrate the links between both positive and negative dimensions of parenting and CU traits in early childhood; however, mixed findings highlight the need for further research.

Using twin-pairs to assess potential bias in polygenic prediction of externalising behaviours across development

Prediction from polygenic scores may be confounded sources of passive gene-environment correlation (rGE; e.g. population stratification, assortative mating, and environmentally mediated effects of parental genotype on child phenotype). Using genomic data from 10,000 twin pairs, we asked whether polygenic scores from the recent externalising genome-wide association study predicted conduct problems, ADHD symptomology and callous-unemotional traits, and whether these predictions are biased by rGE. We ran regression models including within-family and between-family polygenic scores, to separate the direct genetic influence on a trait from environmental influences that correlate with genes (indirect genetic effects). Findings suggested that this externalising polygenic score is a good index of direct genetic influence on conduct and ADHD-related symptoms across development, with minimal bias from rGE, although the polygenic score predicted less variance in CU traits. Post-hoc analyses showed some indirect genetic effects acting on a common factor indexing stability of conduct problems across time and contexts.

Vicarious Emotions of Fear and Pain in Rodents

Affective empathy, the ability to share the emotions of others, is an important contributor to the richness of our emotional experiences. Here, we review evidence that rodents show signs of fear and pain when they witness the fear and pain of others. This emotional contagion creates a vicarious emotion in the witness that mirrors some level of detail of the emotion of the demonstrator, including its valence and the vicinity of threats, and depends on brain regions such as the cingulate, amygdala, and insula that are also at the core of human empathy. Although it remains impossible to directly know how witnessing the distress of others feels for rodents, and whether this feeling is similar to the empathy humans experience, the similarity in neural structures suggests some analogies in emotional experience across rodents and humans. These neural homologies also reveal that feeling distress while others are distressed must serve an evolutionary purpose strong enough to warrant its stability across ~ 100 millions of years. We propose that it does so by allowing observers to set in motion the very emotions that have evolved to prepare them to deal with threats - with the benefit of triggering them socially, by harnessing conspecifics as sentinels, before the witness personally faces that threat. Finally, we discuss evidence that rodents can engage in prosocial behaviors that may be motivated by vicarious distress or reward.

Can psychopathy be prevented? Clinical, neuroimaging, and genetic data: an exploratory study

The aim of the study was to explore the relationship among brain functional activations elicited by an emotional paradigm, clinical scores (PTSD, anxiety, and depression), psychopathic traits, and genetic characteristics (5-HTTLPR) in a group of severely maltreated children compared to a healthy control group before and after the implementation of a Trauma Focused-Cognitive Behavioral Therapy. The final sample consisted of an experimental group of 14 maltreated children (mean age = 8.77 years old, S.D. = 1.83) recruited from a non-governmental shelter in Mexico City for children who had experienced child abuse and a control group of 10 children from the general population (mean age = 9.57 years old, S.D. = 1.91). Both groups were matched according to age and gender and were assessed before and after the implementation of the aforementioned therapy by means of clinical scales and an emotional paradigm that elicited brain activations which were recorded through functional magnetic resonance imaging. Genotyping of the 5-HTTLPR polymorphism was made at first assessment. A region of interest analysis showed amygdala hyperactivation during exposure to fear and anger stimuli in the maltreated children before treatment. Following therapy, a decrease in brain activity as well as a decrease in clinical symptoms were also observed. 5-HTTLPR polymorphism did not show any effect on the severity of clinical symptoms in maltreated children. Trauma-Focused Behavioral Therapy may help reorganize the brain's processing of emotional stimuli. These observations reveal the importance of an early intervention when the mechanisms of neuroplasticity may be still recruited.

Promoting Empathy and Affiliation in Relationships (PEAR) study: protocol for a longitudinal study investigating the development of early childhood callous-unemotional traits

INTRODUCTION

Children with callous-unemotional (CU) traits are at high lifetime risk of antisocial behaviour. Low affiliation (ie, social bonding difficulties) and fearlessness (ie, low threat sensitivity) are proposed risk factors for CU traits. Parenting practices (eg, harshness and low warmth) also predict risk for CU traits. However, few studies in early childhood have identified attentional or physiological markers of low affiliation and fearlessness. Moreover, no studies have tested whether parenting practices are underpinned by low affiliation or fearlessness shared by parents, which could further shape parent-child interactions and exacerbate risk for CU traits. Addressing these questions will inform knowledge of how CU traits develop and isolate novel parent and child targets for future specialised treatments for CU traits.

METHODS AND ANALYSIS

The Promoting Empathy and Affiliation in Relationships (PEAR) study aims to establish risk factors for CU traits in children aged 3-6 years. The PEAR study will recruit 500 parent-child dyads from two metropolitan areas of the USA. Parents and children will complete questionnaires, computer tasks and observational assessments, alongside collection of eye-tracking and physiological data, when children are aged 3-4 (time 1) and 5-6 (time 2) years. The moderating roles of child sex, race and ethnicity, family and neighbourhood disadvantage, and parental psychopathology will also be assessed. Study aims will be addressed using structural equation modelling, which will allow for flexible characterisation of low affiliation, fearlessness and parenting practices as risk factors for CU traits across multiple domains.

ETHICS AND DISSEMINATION

Ethical approval was granted by Boston University (#6158E) and the University of Pennsylvania (#850638). Results will be disseminated through conferences and open-access publications. All study and task materials will be made freely available on lab websites and through the Open Science Framework (OSF).

Morality in middle childhood: the role of callous-unemotional traits and emotion regulation skills

BACKGROUND

The development of morality is vital for fostering prosocial behavior and enhancing both individual and societal well-being. Clarifying what contextual and individual factors play a role in moral processes during childhood can contribute to our understanding of the development of morality. Given the previous acknowledgment of importance, yet lack of existing empirical findings, the study focused on the significance of callous-unemotional traits (i.e., an affective-interpersonal personality trait, related to psychopathy in adulthood) and emotion regulation (i.e., an essential part of socio-emotional competence, and a transdiagnostic factor in the development of psychopathology) for moral emotions and cognitions during middle childhood. The concrete aim was to examine direct and indirect effects of callous-unemotional trait dimensions (callousness, uncaring, unemotionality) onto immoral emotional attribution (i.e., feeling good after immoral decisions) and admissibility of immoral actions (i.e., evaluating immoral actions as being okay) via emotion regulation skills.

METHODS

A cross-sectional study was conducted with 194 children attending Grades 1 to 4, and their primary caregivers. The children completed the Inventory of Callous-Unemotional Traits and caregivers completed the Emotion Regulation Checklist. The children were also presented with a set of moral dilemma vignettes, and asked about the emotions of protagonists who acted immoral, and the admissibility of their actions.

RESULTS

Path-model analysis revealed (1) negative direct effects of emotion regulation skills onto immoral emotional attribution and admissibility of immoral actions, (2) positive direct effects of the dimensions callousness and uncaring onto immoral emotional attribution and admissibility of immoral actions, and (3) negative direct effects of dimensions callousness and uncaring onto emotion regulation skills. Indirect effects, indicating that emotion regulation skills mediate the association between the callous-unemotional trait dimensions and morality, were also found.

CONCLUSION

The findings address a knowledge gap and indicate that emotion regulation skills, callousness, and uncaring play an important role in morality in middle childhood and should be included in frameworks of moral decision-making and development.

Treatment of childhood disruptive behavior disorders and callous-unemotional traits: a systematic review and two multilevel meta-analyses

BACKGROUND

Children with callous-unemotional (CU) traits are at high lifetime risk of antisocial behavior. It is unknown if treatments for disruptive behavior disorders are as effective for children with CU traits (DBD+CU) as those without (DBD-only), nor if treatments directly reduce CU traits. Separate multilevel meta-analyses were conducted to compare treatment effects on DBD symptoms for DBD+CU versus DBD-only children and evaluate direct treatment-related reductions in CU traits, as well as to examine moderating factors for both questions.

METHODS

We systematically searched PsycINFO, PubMed, Cochran Library (Trials), EMBASE, MEDLINE, APA PsycNet, Scopus, and Web of Science. Eligible studies were randomized controlled trials, controlled trials, and uncontrolled studies evaluating child-focused, parenting-focused, pharmacological, family-focused, or multimodal treatments.

RESULTS

Sixty studies with 9,405 participants were included (Mage  = 10.04, SDage  = 3.89 years, 25.09% female, 44.10% racial/ethnic minority). First, treatment was associated with similar reductions in DBD symptoms for DBD+CU (SMD = 1.08, 95% CI = 0.45, 1.72) and DBD-only (SMD = 1.01, 95% CI = 0.38, 1.64). However, DBD+CU started (SMD = 1.18, 95% CI = 0.57, 1.80) and ended (SMD = 0.73, p < .001; 95% CI = 0.43, 1.04) treatment with more DBD symptoms. Second, although there was no overall direct effect of treatment on CU traits (SMD = .09, 95% CI = -0.02, 0.20), there were moderating factors. Significant treatment-related reductions in CU traits were found for studies testing parenting-focused components (SMD = 0.21, 95% CI = 0.06, 0.35), using parent-reported measures (SMD = 0.16, 95% CI = 0.04, 0.28), rated as higher quality (SMD = 0.26, 95% CI = 0.13, 0.39), conducted outside the United States (SMD = 0.19, 95% CI = 0.05, 0.32), and with less than half the sample from a racial/ethnic minority group (SMD = 0.15, 95% CI = 0.002, 0.30).

CONCLUSIONS

DBD+CU children improve with treatment, but their greater DBD symptom severity requires specialized treatment modules that could be implemented alongside parenting programs. Conclusions are tempered by heterogeneity across studies and scant evidence from randomized controlled trials.

Within-Person Bidirectional Associations Over Time Between Parenting and Youths' Callousness

OBJECTIVE

Callousness has been identified as a key driver of aggressive and violent behavior from childhood into early adulthood. Although previous research has underscored the importance of the parenting environment in contributing to the development of youth callousness, findings have generally been confined to the between-individual level and have not examined bidirectionality. In the current study, we test whether aspects of parenting are associated with callousness from childhood to adolescence both between and within individuals, examine the temporal ordering of associations, and test whether these relations are moderated by gender or developmental stage.

METHOD

Data came from a longitudinal study in which parents of 1,421 youth (52% girls; 62% White and 22% Black) from the second, fourth, and ninth grades were interviewed three times, with one year between consecutive interviews.

RESULTS

A random-intercept cross-lagged panel model indicated that elevated youth callousness predicts subsequent increases in parental rejection and decreases in consistency of discipline. Findings were largely similar for boys and girls, but within-individual associations were generally stronger for 4th graders compared to the 2nd and 9th graders.

CONCLUSIONS

Callousness and parenting practices and attitudes were related both at the between-individual and within-individual level. These results have implications for the etiology and treatment of children and adolescents who exhibit callousness.

Pathways to antisocial behavior: a framework to improve diagnostics and tailor therapeutic interventions

The Antisocial Personality Disorder (ASPD), and antisocial behavior (ASB) in general, is associated with significant impact on individuals themselves, their environment, and society. Although various interventions show promising results, no evidence-based treatments are available for individuals with ASPD. Therefore, making informed choices about which treatment can be applied to an individual patient is complicated. Furthermore, contradictory findings on therapy effectiveness and underlying factors of ASB, such as cognitive impairments and personality traits, fuel the debate whether the conceptualization of ASPD in the DSM-5 is accurate and whether this population can be seen as homogeneous. A conceptual framework, based on the reciprocal altruism theory, is presented in which we propose different pathways to ASB. These pathways suggest underlying dynamics of ASB and provide an explanation for previous contradictory research outcomes. This framework is intended to serve as a clinically relevant model that provides directions for improving diagnostics and matching treatments to underlying dynamics in the antisocial population.

The Nature and Nurture of Callous-Unemotional Traits

Callous-unemotional (CU) traits, a risk factor for psychopathy, delineate youths with relatively low empathy and guilt, and identify youths with high risk for chronic and severe antisocial behavior (e.g., rule breaking, aggression). We describe work identifying nature and nurture influences on the development of CU traits. Additionally, we clarify the relationship between CU traits and psychopathy, highlight potential misinterpretations of findings on influences of “nature” versus “nurture,” and discuss treatment implications.

Antipsychotics in the Management of Disruptive Behavior Disorders in Children and Adolescents: An Update and Critical Review

Disruptive behaviour disorders (DBDs) in childhood include conduct disorder (CD) and oppositional defiant disorder (ODD). Though psychological therapies are considered to be the first-line treatment for DBDs, many patients require adjunctive pharmacotherapy for the control of specific symptoms, such as aggression. Three prior systematic reviews have examined the evidence for the use of antipsychotics in DBDs and have concluded that their efficacy is marginal and limited by adverse effects. This paper has two objectives: (i) to summarize the findings of existing systematic reviews of antipsychotics for the management of DBDs in children and adolescents (2012-2017), and (ii) to provide an update to these reviews by examining recent clinical trials of antipsychotics in this population, published in the period from 2 January 2017 to 10 October 2022. The PubMed, Scopus and ScienceDirect databases were searched for relevant citations using the search terms "disruptive behaviour disorder", "oppositional defiant disorder", "conduct disorder" and their variants, along with "antipsychotic", "atypical antipsychotic" and the generic names of all currently approved atypical antipsychotics. Six relevant trials were identified during this period, including five randomized controlled trials and one naturalistic open-label trial. These trials were critically evaluated in terms of outcome measures, efficacy and safety. Overall, the data from these trials suggests that of all available antipsychotics, risperidone appears to be effective in the short-term management of DBDs. All available antipsychotics are associated with significant metabolic adverse effects in this population. These results are discussed in the light of global trends towards increasing off-label prescription of antipsychotic medication in children and adolescents and of recent literature on the neuropharmacology of aggression in this patient population. The need for rational, short-term use of these drugs is highlighted, as well as the importance of post-marketing surveillance for long-term or severe adverse events.

Parent Training Adapted to the Needs of Children With Callous-Unemotional Traits: A Randomized Controlled Trial

Callous-unemotional (CU) traits designate a distinct subgroup of children with early-starting, stable, and aggressive conduct problems. Critically, traditional parenting interventions often fail to normalize conduct problems among this subgroup. The aim of this study was to test whether parent-child interaction therapy (PCIT) adapted to target distinct deficits associated with CU traits (PCIT-CU) produced superior outcomes relative to standard PCIT. In this proof-of-concept trial, 43 families with a 3- to 7-year-old child (M age = 4.84 years, SD = 1.12, 84% male) with clinically significant conduct problems and elevated CU traits were randomized to receive standard PCIT (n = 21) or PCIT-CU (n = 22) at an urban university-based research clinic. Families completed five assessments measuring child conduct problems, CU traits, and empathy. Parents in both conditions reported good treatment acceptability and significantly improved conduct problems and CU traits during active treatment, with no between-group differences. However, linear mixed-effects models showed treatment gains in conduct problems deteriorated for children in standard PCIT relative to those in PCIT-CU during the 3-month follow-up period (ds = 0.4-0.7). PCIT-CU shows promise for sustaining improvements in conduct problems for young children with conduct problems and CU traits, but requires continued follow-up and refinement.

Genetic versus environmental influences on callous-unemotional traits in preadolescence: The role of parenting and parental psychopathology

Children with callous-unemotional (CU) traits are at risk for severe conduct problems. While CU traits are moderately heritable, parenting also predicts risk. However, few studies have investigated whether parenting factors (e.g., acceptance, conflict, parental psychopathology) moderate the etiology of CU traits, while accounting for gene-environment correlations. To address this knowledge gap, we used data from 772 twin pairs from the Adolescent Brain and Cognitive Development Study to test bivariate models that explored overlapping etiological influences on CU traits and child reports of their parenting environment. We also used gene-by-environment interaction models to test whether parenting moderated genetic versus environmental influences. There were no overlapping etiological influences on CU traits and parental acceptance, but modest genetic and non-shared environmental overlap between CU traits and family conflict. Parental acceptance and psychopathology moderated non-shared environmental influences, with stronger non-shared environmental influences on CU traits among children who experienced lower parental acceptance and greater parental psychopathology. Family conflict only moderated environmental influences when models did not covary for conduct problems. Parental acceptance and parental psychopathology may be specific environmental protective and risk factors for CU traits, whereas family conflict may represent a general environmental risk factor for both CU traits and conduct problems.

Parenting moderates the etiology of callous-unemotional traits in middle childhood

BACKGROUND

Callous-unemotional (CU) traits are associated with chronic and escalating trajectories of antisocial behavior. Extant etiologic studies suggest that heritability estimates for CU traits vary substantially, while also pointing to an environmental association between parenting and CU traits.

METHODS

We used twin modeling to estimate additive genetic (A), shared environmental (C), and nonshared environmental (E) influences on CU traits, measured with the Inventory of Callous-Unemotional Traits (ICU) and its subscales. Our sample included 600 twin pairs (age 6-11, 230 monozygotic) from neighborhoods with above-average levels of family poverty, a risk factor for antisocial behavior. We examined the extent to which correlations between parenting, measured via parent and child report on the Parental Environment Questionnaire, and CU traits reflected genetic versus environmental factors. Then, we tested whether parenting moderated the heritability of CU traits.

RESULTS

In the context of lower-income neighborhoods, CU traits were moderately to highly heritable (A = 54%) with similar moderate-to-high nonshared environmental influences (E = 46%). Bivariate models revealed that associations between CU traits and warm parenting were genetic (rA = .22) and environmental (rE = .19) in origin, whereas associations between CU traits and harsh parenting were largely genetic in origin (rA = .70). The heritability of CU traits decreased with increasing parental warmth and decreasing harshness.

CONCLUSIONS

Callous-unemotional traits are both genetic and environmental in origin during middle childhood, but genetic influences are moderated by parenting quality. Parenting may be an important target for interventions, particularly among youth with greater genetic risk.

Environmental Predictors of Within-Person Changes in Callous-Unemotional Traits among Justice-Involved Male Adolescents

OBJECTIVE

Youth who display elevated callous-unemotional (CU) traits are at risk for negative developmental outcomes. Previous studies demonstrate that environmental conditions contribute to elevated levels of CU traits, but the majority of this work focuses on a single source of environmental influence. To better understand how environmental conditions contribute to changes in CU traits during adolescence, the current study examined the time-varying relation between CU traits, parent, peer, and community conditions.

METHOD

Using data from the longitudinal Pathways to Desistance study (N = 1,026 males, Mage = 15.98, SD = 1.16; 40.94% Black, 34.11% Latino, 20.66% White, 4.29% Other), full-factorial fixed effect regression models were implemented to examine how parental hostility, antisocial peers, community violence, and neighborhood disorder are individually and interactively associated with within-person changes in CU traits during adolescence (15-21 years).

RESULTS

Results indicated that proximal conditions (i.e., negative parenting, antisocial peers) had more consistent associations with CU traits than distal conditions (i.e., neighborhood disorder, community violence). Affiliation with antisocial peers was not significantly related to CU traits when youth were simultaneously exposed to high community violence and low neighborhood disorder. Further, the association between CU traits and impact of living in high disordered, high violence neighborhoods was stronger for younger youth.

CONCLUSION

Results indicate that the association among parents, peers, and CU trait development is more nuanced than previously suggested, such that the risk that each environmental condition poses is moderated by a youth's age and their exposure to distal conditions.

Dimensional Latent Structure of Callous-Unemotional Traits in German Adolescents: Results from Taxometric Analyses

A large amount of research has addressed the issue of the latent status of psychiatric disorders and related phenomena. We used a new taxometric approach developed by Ruscio to examine the latent status of callous-unemotional (CU) traits in a large representative study of German ninth graders (N = 3,878). Rather than estimating a putative taxon base rate and using that estimate to generate the taxon comparative data, we estimated CCFI profiles with each base rate estimate between 2.5% and 97.5% in increments of 2.5%. Results of different indicator sets clearly suggested a dimensional solution. This finding is consistent with different studies showing the dimensionality of psychopathy in adolescents. In summary, the results of this study point to the need for critical reflection in defining a high-risk-group in the context of CU traits. However, further studies are necessary to substantiate this result in different samples using different measurement approaches.

Describing Callous Unemotional Traits and Stressful Life Event Trajectories: Differences on Risk Factors and Mental Health Outcomes from the Age of 3 to 10

Callous Unemotional (CU) traits are associated with different environmental risk factors, such as negative stressful life events (SLE). The most common studied SLE associated with CU trait has been childhood maltreatment, but less is known about how other SLE impact the development of CU traits. Therefore, this work examines risk factors, personal factors (executive functioning), and mental health outcomes associated with the trajectories of Callous Unemotional (CU) traits and Stressful Life Events (SLE) in a community sample of children. A cohort of 377 preschoolers were followed up between ages 3 and 10. Several risk factors and outcomes for three trajectory groups (high CU/SLE; high CU/low SLE; and the reference group with low CU/SLE) were analyzed by using multiple post-hoc comparisons. We hypothesized that children with high CU/SLE would face more contextual risk factors, more executive functioning difficulties and more mental health problems than children with high CU/low SLE or the reference group. At the age of 3, children who showed high CU/SLE faced more early contextual adversity, including socioeconomic difficulties and maternal antisocial behavior than the other groups of children. At the age of 10, children with high CU/SLE presented more peer problems and higher psychopathology symptoms than the reference group, but no differences on mental health outcomes in comparison to the high CU/low SLE group. These results have potential implications for clinical practice and studies attempting to identify different CU subtypes in children.

The Moderating Role of Maternal CU Traits in the Stability of Justice-Involved Adolescents' CU Traits

OBJECTIVE

Callous-unemotional (CU) traits are associated with chronic and severe antisocial behavior. Although previous research has found that parents play an important role in the etiology and maintenance of youth CU traits, little research has examined the extent that parents' own CU traits impact the stability of their children's CU traits. The present study investigated the moderating role of maternal CU traits on developmental changes in youth CU traits.

METHOD

A sample of 346 mother-son dyads, in which all youth were justice-involved males (Mage = 15.81; 57.80% Latino, 20.52% White, 18.21% Black, 3.47% other race/ethnicity), across three states (California, Louisiana, and Pennsylvania) completed a semi-structured interview.

RESULTS

Youth exhibited a decrease in CU traits over 30 months. Mothers' CU traits moderated this relation, such that high maternal CU traits were associated with a smaller decrease in CU traits than low or average maternal CU traits, both when considering youth CU traits continuously and using a clinically significant cut score. The findings remained for continuous CU traits even after accounting for environmental factors (i.e., maternal warmth, maternal hostility, victimization, and witnessing violence), and these environmental factors did not vary over time.

CONCLUSION

The results highlight the importance of maternal influence in understanding how youth CU traits change over time, and have important implications for the use of parenting and family-level interventions among justice-involved youth.

Childhood Maltreatment and Adolescent Cyberbullying Perpetration: A Moderated Mediation Model of Callous-Unemotional Traits and Perceived Social Support

Although childhood maltreatment has been shown to play an important role in adolescent cyberbullying perpetration, little is known about mediating and moderating mechanisms underlying this relationship. The current study investigated the mediating role of callous-unemotional (CU) traits in the association between childhood maltreatment and adolescent cyberbullying perpetration, as well as the moderating role of perceived social support. A total of 2,407 Chinese adolescents (aged 11-16 years, M_age = 12.75 years, SD = 0.58) completed the measures of childhood maltreatment, CU traits, cyberbullying perpetration, and perceived social support. The results showed that CU traits partially mediated the relationship between childhood maltreatment and adolescent cyberbullying perpetration. Furthermore, perceived social support moderated the relationship between childhood maltreatment and CU traits, as well as CU traits and cyberbullying perpetration. Specifically, childhood maltreatment had a greater impact on CU traits for adolescents with higher levels of perceived social support and the predictive function of CU traits on cyberbullying perpetration was stronger for adolescents with low levels of perceived social support.

The Impact of the COVID-19 Pandemic on Children's Conduct Problems and Callous-Unemotional Traits

The COVID-19 pandemic has dramatically altered family life, but whether family exposures to and worries about the COVID-19 pandemic has impacted child conduct problems (CP) and callous-unemotional (CU) traits is unknown. Thus, we evaluated 303 parents (Mage = 38.04; SD = 5.21; 92.4% biological mothers) and children (Mage = 6.43; SD = 2.13; 51.8% female) during a four-month period early in the pandemic. We examined associations between parental exposures to COVID-19, parental worries about the pandemic, harsh and warm parenting practices, and child CP and CU traits. Although more parental worries were not directly related to parenting practices, more worry about COVID-19 was specifically related to higher levels of child CP, particularly parental worries about themselves or family members contracting the virus. Our findings add to a growing literature demonstrating the burden that the pandemic has placed on families and its implications for children's mental health.

Positive and negative parenting in conduct disorder with high versus low levels of callous-unemotional traits

Less is known about the relationship between conduct disorder (CD), callous-unemotional (CU) traits, and positive and negative parenting in youth compared to early childhood. We combined traditional univariate analyses with a novel machine learning classifier (Angle-based Generalized Matrix Learning Vector Quantization) to classify youth (N = 756; 9-18 years) into typically developing (TD) or CD groups with or without elevated CU traits (CD/HCU, CD/LCU, respectively) using youth- and parent-reports of parenting behavior. At the group level, both CD/HCU and CD/LCU were associated with high negative and low positive parenting relative to TD. However, only positive parenting differed between the CD/HCU and CD/LCU groups. In classification analyses, performance was best when distinguishing CD/HCU from TD groups and poorest when distinguishing CD/HCU from CD/LCU groups. Positive and negative parenting were both relevant when distinguishing CD/HCU from TD, negative parenting was most relevant when distinguishing between CD/LCU and TD, and positive parenting was most relevant when distinguishing CD/HCU from CD/LCU groups. These findings suggest that while positive parenting distinguishes between CD/HCU and CD/LCU, negative parenting is associated with both CD subtypes. These results highlight the importance of considering multiple parenting behaviors in CD with varying levels of CU traits in late childhood/adolescence.

Psychopathy

Psychopathy is a personality disorder characterized by a constellation of affective, interpersonal, lifestyle and antisocial features whose antecedents can be identified in a subgroup of young people showing severe antisocial behaviour. The prevalence of psychopathy in the general population is thought to be ~1%, but is up to 25% in prisoners. The aetiology of psychopathy is complex, with contributions of both genetic and environmental risk factors, and gene-environment interactions and correlations. Psychopathy is characterized by structural and functional brain abnormalities in cortical (such as the prefrontal and insular cortices) and subcortical (for example, the amygdala and striatum) regions leading to neurocognitive disruption in emotional responsiveness, reinforcement-based decision-making and attention. Although no effective treatment exists for adults with psychopathy, preliminary intervention studies targeting key neurocognitive disturbances have shown promising results. Given that psychopathy is often comorbid with other psychiatric disorders and increases the risk of physical health problems, educational and employment failure, accidents and criminality, the identification of children and young people at risk for this personality disorder and preventative work are important. Indeed, interventions that target the antecedents of psychopathic features in children and adolescents have been found to be effective.

Associations Between Parental Psychopathic Traits, Parenting, and Adolescent Callous-Unemotional Traits

Callous-unemotional (CU) traits (i.e., callousness, low empathy, shallow affect) have been conceptualized as a downward extension of the interpersonal and affective components of adult psychopathy and are associated with stable and severe antisocial behavior. Research suggests that CU traits are moderately heritable, but also influenced by environmental factors, particularly parenting. We examined associations among mother and father psychopathic traits, parenting practices, and offspring CU traits in a community sample of 550 adolescent twins (Mean age = 13.99 years; SD 2.37; 56.4% male), incorporating multiple informants (mothers, fathers, child). Parental interpersonal-affective psychopathic traits were associated with adolescent CU traits and negative parenting (increased harshness, reduced warmth). Moreover, increased parental harshness and reduced warmth partially explained associations between parental interpersonal-affective traits and adolescent CU traits. There was also a significant direct effect specifically between mother interpersonal-affective traits and adolescent CU traits. Finally, using a twin difference design, we confirmed that adolescent CU traits were significantly impacted by non-shared environmental parenting influences (increased harshness, reduced warmth). These results suggest that mother and father interpersonal-affective traits appear to impact parenting practices and serve as risk factors for adolescent CU traits. However, many of the findings did not replicate when using cross-informant reports and were only present within single informant models, highlighting a role for shared informant variance as well. The results suggest the importance of accounting for parent personality in the development of effective parenting interventions for CU traits.

Role of Callous and Unemotional (CU) Traits on the Development of Youth with Behavioral Disorders: A Systematic Review

Numerous studies have shown that youth with behavioral disorders (BD) present an increased risk for developing severe and persistent antisocial behaviors in adulthood. Retrospective research notes that not all children and adolescents follow a negative trajectory and explains this heterogeneity in particular by the severity of CU traits. Our study examines how these traits affect the functioning of children and adolescents with BD. Method: A systematic literature review conducted through various databases and using different keywords made it possible to analyze 52 studies published from 2015 to 2020 that measured the bidirectional effects of CU traits on the functioning of young. Results: Out of the 52 studies, 47 analyzed links between CU traits and neurobiological or mental health, 20 examined family and school contexts, eight focused on social adjustment, 10 on social interactions and 19 measured links with cognitive functioning, especially executive functions. Conclusion: Consistent with previous recommendations in the field, our findings emphasize the importance of assessing the presence of UC traits in early childhood to prevent the emergence of comorbid disorders and to target multimodal (early) interventions to influence the life trajectories of youth with high CU traits.

Genetic and environmental influences on the developmental trajectory of callous-unemotional traits from childhood to adolescence

BACKGROUND

This study examined the genetic and environmental influences underlying baseline level and developmental course of callous-unemotional (CU) traits across childhood and adolescence.

METHODS

The data on 8,958 twin pairs (3,108 MZ twin pairs and 5,850 DZ twin pairs) from the Twins Early Development Study were analysed. CU traits were assessed at ages 7, 9, 12 and 16 by mothers and analysed using a biometric latent growth model.

RESULTS

Individual differences in the baseline level of CU traits were highly heritable (76.5%), while the heritability of the developmental course of CU traits was moderate (43.6%). The genetic influences on baseline level and developmental course of CU traits were mostly nonoverlapping. Nonshared environment made a modest contribution to the baseline level of CU traits (21.7%). Nonshared environmental influences on the developmental course of CU traits were moderate (43.2%), with nearly half of them being the same as those influencing the baseline level and just over half being specific. Shared environmental effects did not contribute to systematic change across childhood and adolescence but were rather age-specific.

CONCLUSIONS

Our findings demonstrate that rather than only being conceptualized as factors of stability, genes also play a dynamic role in explaining systematic change in CU traits. Genetic effects for the initial risk and subsequent development of CU traits are not the same. In addition to genetic factors, nonshared environmental influences play an important role in explaining why some children will increase or maintain their CU traits over time, whereas other will desist. New genetic and environmental influences with age suggest that repeated, age-tailored interventions may be required throughout development to make a lasting difference in the presentation of CU traits and associated outcomes.

Commentary: Implications for future research on the genetic and environmental causes of callous-unemotional traits - a commentary on Takahashi et al (2020)

Takahashi et al. (2020) showed that CU traits at age 7 were highly heritable, that the genetic influences underlying the course of CU traits from age 7 to 16 were largely independent from those underlying the initial level, and that the genetic influences on CU traits in early childhood were substantially different from the genetic influences on these traits in adolescence. This commentary on these important and provocative findings focuses on their implications for future research. Specifically, it notes that future studies attempting to find genetic loci related to CU traits need to consider that such loci may differ depending on the age of the sample and this research needs to consider several important considerations when measuring CU traits that can influence the results. Further, the results of Takahashi et al highlight the importance of environmental influences on the stability of CU traits that could play an important role in treatment.

Epistemic Trust and the Emergence of Conduct Problems: Aggression in the Service of Communication

Fonagy and colleagues have recently proposed that deficits in the capacity for epistemic trust (i. e., the expectation that interpersonal communication is relevant to the addressee) are fundamental to psychopathology. In this paper, we consider the implications of this hypothesis for understanding the role of aggression in conduct disorder and conduct problems more generally. Our main proposal is to view conduct problems not only as reflecting dysregulation, but as an adaptation that allows communication with others who are (or are perceived to be) unreliable. Our formulation hinges on two propositions. The first one is to view aggression as a modality of communication adapted to scenarios in which the communicator expects the audience to have low epistemic trust in the communicator. The second idea is to conceptualize the failed "unlearning of aggression" as reflecting a lack of interest in maintaining one's reputation as a communicator, which in turn stems from a lack of epistemic trust in other communicators. In this paper, we discuss these ideas and examine how they may account for the developmental pathways that lead young people to develop conduct problems.

Conduct Disorders and Empathy Development

Childhood conduct disorders, a serious mental health concern, put children at risk for significant mental health problems throughout development. Elevations on callous-unemotional (CU) traits designate a subgroup of youth with conduct disorders who have unique causal processes underlying their problem behavior and are at a particularly high risk for serious impairment relative to others with these disorders. As a result, these traits have recently been integrated into major diagnostic classification systems for conduct disorders. Given that CU traits are partly defined by deficits in empathy, we review research on empathy development in typically developing children and use this research to (a) advance theories on the specific emotional deficits that may be associated with CU traits, (b) explain the severe pattern of aggressive behavior displayed by children with elevated CU traits, and (c) suggest possible ways to enhance prevention and treatment for children with conduct disorders and elevated CU traits.

Genome-Wide DNA Methylation Patterns in Persistent Attention-Deficit/Hyperactivity Disorder and in Association With Impulsive and Callous Traits

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that often persists into adulthood. ADHD and related personality traits, such as impulsivity and callousness, are caused by genetic and environmental factors and their interplay. Epigenetic modifications of DNA, including methylation, are thought to mediate between such factors and behavior and may behave as biomarkers for disorders. Here, we set out to study DNA methylation in persistent ADHD and related traits. We performed epigenome-wide association studies (EWASs) on peripheral whole blood from participants in the NeuroIMAGE study (age range 12-23 years). We compared participants with persistent ADHD (n = 35) with healthy controls (n = 19) and with participants with remittent ADHD (n = 19). Additionally, we performed EWASs of impulsive and callous traits derived from the Conners Parent Rating Scale and the Callous-Unemotional Inventory, respectively, across all participants. For every EWAS, the linear regression model analyzed included covariates for age, sex, smoking scores, and surrogate variables reflecting blood cell type composition and genetic background. We observed no epigenome-wide significant differences in single CpG site methylation between participants with persistent ADHD and healthy controls or participants with remittent ADHD. However, epigenome-wide analysis of differentially methylated regions provided significant findings showing that hypermethylated regions in the APOB and LPAR5 genes were associated with ADHD persistence compared to ADHD remittance (p = 1.68 * 10-24 and p = 9.06 * 10-7, respectively); both genes are involved in cholesterol signaling. Both findings appeared to be linked to genetic variation in cis. We found neither significant epigenome-wide single CpG sites nor regions associated with impulsive and callous traits; the top-hits from these analyses were annotated to genes involved in neurotransmitter release and the regulation of the biological clock. No link to genetic variation was observed for these findings, which thus might reflect environmental influences. In conclusion, in this pilot study with a small sample size, we observed several DNA-methylation-disorder/trait associations of potential significance for ADHD and the related behavioral traits. Although we do not wish to draw conclusions before replication in larger, independent samples, cholesterol signaling and metabolism may be of relevance for the onset and/or persistence of ADHD.