Callous-unemotional Research Articles

Affective and Behavioral Responses to Time-Out in Preschool Children With Conduct Problems and Varying Levels of Callous-Unemotional Traits

Punishment insensitivity characterizes individuals with callous-unemotional (CU) traits. This has been put forward as an explanation for their persistent conduct problems despite intervention. The purpose of the current study was to compare the emotional and behavioral responses to parent-implemented time-out within a behavioral parent training intervention between children with conduct problems who are high versus low on CU traits. Children (N = 87; M age = 4.88 years, SD = 1.32; 78% male) referred to a specialty clinic for the treatment of conduct problems were observed and coded during time-out, and their parents rated their conduct problem severity and CU traits using psychometrically robust measures. Children with conduct problems and high CU traits showed significantly more calm/neutral emotion and less negative emotion upon initial placement in time-out by parents, but did not engage in more negative behaviors or spend longer in time-out relative to children with conduct problems alone. After a minimum of 3 weeks of exposure to this form of parental discipline, most children complied with effective parental commands in that they did not require time-out for noncompliance during the fourth discipline-focused treatment session. Findings have implications for understanding why children with CU traits continue showing high levels of conduct problems post behavioral interventions, and they lend further support for the need to personalize treatment to their distinct needs.

Do Juveniles Who Have Committed Sexual Offenses Have Higher Callous-Unemotional Traits Compared to Juveniles Who Have Committed General Offenses? A Systematic Review.

The importance of assessing psychopathic traits in juveniles who have committed sexual offenses has been established in individuals who demonstrate a particularly severe and violent pattern of behavior. Additionally, the assessment of these traits in other juveniles might be relevant considering that higher levels of these traits represent an increased probability of the juvenile committing offenses. This study is a systematic review of the literature about the presence of callous-unemotional (CU) traits in juveniles who have committed sexual and non-sexual offenses, in order to ascertain eventual differences between these groups regarding the presence of CU traits. Studies were obtained from multiple databases, with predefined exclusion and inclusion criteria, according to PRISMA-P guidelines. A total of 18 studies were reviewed and included in the final analysis. The 18 studies used measures of CU traits and reported descriptive categories of CU traits in juveniles who have committed general offenses or juveniles who have committed sexual offenses. Meta-analytic procedures such as pooled means, pooled variances, and pooled standard deviations are presented in this study. The main conclusion obtained is that juveniles who have committed general offenses present higher levels of CU traits compared to juveniles who have committed sexual offenses. Although the review highlights limitations in the literature, the identification of these characteristics in different types of juveniles who have committed offenses is important to shed light on the phenomenon and develop interventions better suited to their characteristics. Recommendations for future research are also presented.

Callous-unemotional traits and pre-ejection period in response to reward.

Callous-unemotional (CU) traits have important utility in distinguishing individuals exhibiting more severe and persistent antisocial behavior, and our understanding of reward processing and CU traits contributes to behavioral modification. However, research on CU traits often investigated reward alongside punishment and examined solely on average reward reactivity, neglecting the reward response pattern over time such as habituation. This study assessed individuals' pre-ejection period (PEP), a sympathetic nervous system cardiac-linked biomarker with specificity to reward, during a simple reward task to investigate the association between CU traits and both average reward reactivity and reward response pattern over time (captured as responding trajectory). A heterogeneous sample of 126 adult males was recruited from a major metropolitan area in the US. Participants reported their CU traits using the Inventory of Callous-Unemotional Traits and completed a simple reward task while impedance cardiography and electrocardiogram were recorded to derive PEP. The results revealed no significant association between average PEP reward reactivity and CU traits. However, CU traits predicted both linear and quadratic slopes of the PEP reactivity trajectory: individuals with higher CU traits had slower habituation initially, followed by a rapid habituation in later blocks. Findings highlight the importance of modeling the trajectory of PEP reward response when studying CU traits. We discussed the implications of individuals with high CU traits having the responding pattern of slower initial habituation followed by rapid habituation to reward and the possible mechanisms.

Concurrent Associations Between Callous-Unemotional Traits, Moral Disengagement, and Bullying Perpetration in Adolescence

The aim of the current study was twofold. The first aim was to examine whether callous-unemotional (CU) traits are directly related to moral disengagement and bullying perpetration as well as whether CU traits are indirectly related to bullying perpetration mediated by moral disengagement among adolescents. The second aim was to examine whether the three distinct dimensions of CU—callousness, uncaringness, and unemotionality—are directly related to moral disengagement and bullying perpetration, as well as whether they are indirectly related to bullying perpetration mediated by moral disengagement among adolescents. Self-report survey data from 706 adolescents ( Mage = 14.5) from 20 schools in Sweden were gathered and analyzed using structural equation modeling. The findings suggest that CU traits were positively and directly linked to bullying perpetration, but also indirectly mediated by moral disengagement. Similarly, callousness and uncaringness showed direct and indirect associations with bullying perpetration, whereas unemotionality was found to be only indirectly associated with bullying perpetration. Unemotionality had the weakest connection to moral disengagement and was not directly related to bullying perpetration, whereas callousness, in particular, but also uncaringness, had stronger connections to moral disengagement and bullying perpetration. In sum, the findings underscore the importance of explicitly integrating moral considerations into endeavors aimed at preventing school bullying among adolescents.

Exploring the Unique and Interactive Effects Between Callous-Unemotional and Autistic Traits with Parental Practices, Care, and Distress in a Community Sample.

Parental practices and stress are associated with both CU and autistic traits, with parents of children with these traits facing challenges that other parents do not encounter. However, the majority of available studies focused mainly on the unique effects of CU and autistic traits with parental stress and practices without exploring their interaction. The current study examines the distinct associations and interactions between CU and autistic traits with parental practices (parental involvement, poor monitoring, inconsistent discipline, and corporal punishment), care, and distress after considering the effect of conduct problems (CPs), age and sex in a Greek-Cypriot sample (N = 146, Mage = 7.30, SD = 1.43). Hierarchical multiple regression analysis revealed that children with CU traits were more likely to experience negative parenting, while parents showed heightened levels of distress. Notably, the study found no association between CU traits and positive parental practices. Further analysis indicated no significant relation between autistic traits and interactions with the target variables, signifying that these traits are not associated with difficulties in parenting and distress. No sex differences were found in all analyses. Age was negatively significant only in relation to parental distress These findings provide valuable insights into the impact of CU traits and underscore the need for additional studies investigating the impact of autistic traits, possibly within clinical samples.

Dimensions of Parenting and Children's Conduct Problems: The Importance of Considering Children's Callous-Unemotional Traits.

Research has clearly indicated that the development of serious behavioral problems in children and adolescents is influenced by parenting. However, recent research has refined the role of parenting by showing the importance of distinguishing between different types of parenting and in considering the role of callous-unemotional traits (CU traits) and conduct problems (CP) of the children. In the current study, we advance this research by distinguishing between emotional (e.g., parental warmth; parental hostility) and behavioral (e.g., use of positive reinforcement; inconsistent discipline/harsh discipline) aspects of parenting and by considering the way parents respond to children's emotions (i.e., coaching and dismissing). The sample consisted of 136 mothers (M = 38.09 years, SD = 4.51 years, 45.41% high school degree) with a child (age range 3-5 years) enrolled in kindergarten in central Italy. Multiple regression analyses indicated that, after controlling for level of CP, use of positive reinforcement (β = -0.31, p < 0.001) and warm feelings (β = -0.22, p < 0.05), remained associated with CU traits and punitive parenting was no longer significant. Consistent with predictions, use of positive reinforcement was no longer associated with conduct problems when controlling for CU traits and the positive associations with punitive parenting (β = 0.24, p < 0.05) and negativity (β = 0.36, p < 0.001) remained significant. These findings support the need for continued research that considers both the emotional and behavioral aspects of parenting and disentangles their associations with conduct problems and CU traits. Such research could not only advance causal theories for children with conduct problems but also help to guide more effective treatments, especially for those with elevated CU traits who often leave treatment with significant conduct problems remaining.

Maternal and Paternal Parenting and Maltreatment in Relation to Callous-Unemotional Traits in Detained Male Adolescents

This study investigated the relationship between parenting practices, childhood maltreatment (CM), callous-unemotional (CU) traits, and conduct disorder (CD) symptoms among 275 detained adolescent boys (Mage = 16.96). CU traits, and paternal and maternal parenting were assessed via self-report questionnaires. A diagnostic interview was used to assess CD symptoms. Regression analyses revealed that harsh parenting and physical maltreatment were positively associated with CU traits after controlling for CD symptoms, whereas warm parenting was significantly negatively related to CU traits. After controlling for the overlap between parenting and CM, only parenting was significantly positively related to CU traits. Findings, finally, showed that CU traits did not moderate the link between parenting (or CM) and CD symptoms. The study underscores that it is important to consider experiences with parenting practices and CM in detained adolescents with heightened CU traits.

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.

The amygdala volume moderates the relationship between childhood maltreatment and callous-unemotional traits in adolescents with conduct disorder.

CU traits, characterized by shallow affect, lack of fear, and absence of remorse, have been moderately associated with childhood maltreatment in a recent meta-analysis. However, the potential impact of brain structures remains undetermined. This paper examines the relationship between callous-unemotional (CU) traits, childhood maltreatment, and amygdala volumes. In this study, we used a region-of-interest (ROI) analysis to explore the interaction between the volumes of the amygdala, childhood maltreatment, and the manifestation of CU traits in adolescents diagnosed with conduct disorder (CD, N = 67), along with a comparison group of healthy-control youths (HCs, N = 89). The ROI analysis revealed no significant group differences in the bilateral amygdalar volumes. Significant positive correlation was discovered between all forms of child maltreatment (except for physical neglect) and CU traits across subjects. But the interaction of physical abuse and amygdala volumes was only significant within CD patients. Notably, a sensitivity analysis suggested that gender significantly influences these findings. These results contribute critical insights into the etiology of CU traits, emphasizing the need for customized clinical assessment tools and intervention strategies.

Peer Victimization and Callous-Unemotional Traits: The Impact of Parents and Teachers.

Research on the link between peer victimization and callous-unemotional (CU) traits has primarily relied on cross-sectional designs and yielded equivocal findings. In light of the poor outcomes related to peer victimization and CU traits, it is important to determine whether this link is reciprocal in nature and to identify factors that may influence its strength. Accordingly, the current study investigated the bidirectional association between peer victimization and CU traits over a 6-month period, accounting for the moderating effects of parents (i.e., support and hostility) and teachers (i.e., support and conflict). Participants included 284 third- through fifth-grade students (ages 7-12; 51.8% boys; 51.1% Hispanic) and their homeroom teachers. Children provided ratings of peer victimization, parental hostility, and parent and teacher support. Teachers provided ratings of CU traits and student-teacher conflict. A series of cross-lagged panel models were estimated. Results revealed that, at higher levels of parental hostility, peer victimization predicted increases in CU traits over time; in contrast, peer victimization predicted decreases in CU traits at lower levels of parental hostility. Surprisingly, at higher levels of teacher conflict, peer victimization predicted decreases in CU traits over time. CU traits did not interact with parent or teacher variables to predict subsequent peer victimization. Moreover, parental hostility was positively associated with subsequent peer victimization, whereas teacher support predicted decreases in victimization over time. These findings build on previous research examining environmental influences on the expression of CU traits by highlighting peer victimization and parental hostility as potential risk factors.

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

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. 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). 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. 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.

Callous-unemotional behaviors and conduct problems in Chinese preschoolers: the moderating roles of surgency and gender.

Conduct problems in children are related to callous-unemotional (CU) behaviors. However, results of the relationships between CU behaviors and conduct problems among preschoolers mainly focused on Western countries, no studies have examined whether CU behaviors predict conduct problem in Chinese preschoolers. The primary objective of the current study therefore was to examine the associations between CU behaviors and conduct problems as well as the moderating effects of surgency and child gender in Chinese preschool children. The present study randomly selected 2,154 children (1,043 boys, Mage = 56 months, SD = 10.47) from six kindergartens in Shanghai, People's Republic of China. Mothers rated children's surgency and teachers reported children's CU behaviors and conduct problems. Results demonstrated that CU behaviors were positively associated with conduct problems. Surgency and child gender significantly moderated these associations. Specifically, CU behaviors were positively associated with conduct problems, with a stronger effect found for high levels of surgency. CU behaviors had a positive association with conduct problems, with a stronger effect found for boys. This study indicate that temperament and gender characteristics influence conduct problems in preschoolers who exhibit high levels of CU behaviors. As well, the findings emphasize the significance of considering the meaning and implication of CU behaviors in Chinese culture.

Fearlessness as an Underlying Mechanism Leading to Conduct Problems: Testing the INTERFEAR Model in a Community Sample in Spain.

Conduct problems (CP) in childhood and adolescence have a significant impact on the individual, family, and community. To improve treatment for CP, there is a need to improve the understanding of the developmental pathways leading to CP in boys and girls. Prior research has linked the child's fearlessness and callous-unemotional (CU) traits, as well as experiences of parental warmth and punitive parenting, to CP. However, few studies have tested the interplay of these factors in contributing to future CP development. The present study aimed to test the InterFear model, which suggests that fearlessness in early childhood leads to CP through an indirect pathway involving low positive parenting, high negative/punitive parenting, and callous-unemotional (CU) traits. The sample included 2467 Spanish children (48.1% girls; Mage = 4.25; SD = 0.91), followed up across a five-year period. Besides a direct association between fearlessness in early childhood and future CP, the results found an indirect pathway whereby fearlessness reduces positive parenting and increases punitive parenting, which contributes to the development of CU traits and sets the stage for CP in later childhood. The specific indirect effect from fearlessness to CP via CU traits accounted for most of the variance, suggesting the existence of a temperamental pathway independent of parental variables. Further, two additional indirect pathways, exclusive of fearlessness, were identified, which started with low parental warmth and positive parenting, leading to CP via CU traits. These findings support the InterFear model, demonstrating multiple pathways to CP with the involvement of fearlessness, parenting practices, and CU traits. This model might play a pivotal role in the development of targeted prevention and intervention strategies for CP.

Factor structure of callous unemotional traits and its associations with morality in middle childhood in a German community sample

The present study focuses on assessing the psychometric properties of the Inventory of Callous-Unemotional Traits (ICU) in a German community sample of middle childhood participants. Previous research on the ICU has primarily been conducted in different samples and countries, with inconsistent results, i.e., different models in different samples and little attention given to German middle childhood populations. A critical need to deepen the understanding of callous-unemotional traits in middle childhood is urgently needed. Hence, this study aims to evaluate the factor structure of the ICU within a sample of children in middle childhood from Germany. A total of 824 children aged 7 to 12 years (M = 10.34, SD = 1.65) participated (52.18% boys). The ICU, a self-report measure, was employed to assess callous-unemotional traits in middle childhood. Additionally, this study also examines the relationship between callous-unemotional traits and morality. Confirmatory factor analyses were conducted to evaluate various model structures based on previous research. The best-fitting model was found to be a two-factor model consisting of callousness and uncaring factors. The moral self shows a stronger overarching association with the uncaring factor than with callousness. The study’s findings provide valuable insights into the applicability of the ICU across various age ranges, particularly in childhood, and the results are discussed in the context of other identified models and age groups and suggest that assessing CU traits requires a detailed perspective, taking into account other developmental factors.

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

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. 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. 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. 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.

Callous-Unemotional Traits and Emotion Perception Accuracy and Bias in Youths.

This study investigated the associations among conduct problems, callous-unemotional (CU) traits, and indices of emotion recognition accuracy and emotion recognition bias obtained from human faces. Impairments in emotion recognition were considered within broader, impaired emotional and social functioning. The sample consisted of 293 middle-school students (51.19% girls; M age = 12.97 years, SD = 0.88 years). In general, CU traits were associated with less accuracy in recognizing emotions, especially fearful and angry faces, and such deficits in emotional recognition were not associated with conduct problems independent of CU traits. These results support the importance of studying potential deficits in the recognition of emotions other than fear. Furthermore, our results support the importance of considering the role of CU traits when studying emotional correlates of conduct problems. For children scoring high on CU traits, the emotion recognition accuracy of anger was low irrespective of the level of conduct problems, whereas in children scoring low on CU traits, less accuracy in recognizing emotions was related to increases in conduct problems. Finally, our results support the need for research to not only focus on accuracy of emotional recognition but also test whether there are specific biases leading to these inaccuracies. Specifically, CU traits were associated not only with lower accuracy in recognizing fearful faces but also with a tendency to interpret fearful faces as angry. This suggests that the emotional deficit associated with CU traits is not just a deficit in empathic concern toward others distress but also includes a tendency to overinterpret emotions as potential threats to oneself.

The Interplay between Fear Reactivity and Callous-Unemotional Traits Predicting Reactive and Proactive Aggression.

Research has indicated that youths with CU traits are fearless, and this fearlessness plays a bidirectional role in both the development of CU traits and engagement in aggressive behavior. However, research specifically testing the role of fear in the association between CU traits and aggression is scarce. The goal of the current study was to test if fear reactivity, both conscious (self-report) and automatic (skin conductance reactivity; SCR), moderated the association between CU traits and aggression subtypes (reactive and proactive aggression). Participants included 161 adolescents (Mage = 15 years) diagnosed with conduct disorder. CU traits were assessed using the self-report Inventory of Callous-Unemotional Traits. Conscious and automatic fear reactivity were measured during a virtual reality rollercoaster using the Self-Assessment Manikin and skin conductance reactivity (SCR), respectively. Hierarchical regressions found that high fear reactivity on SCR moderated the link between CU traits and reactive aggression, while feeling more excited during fear induction moderated the link between CU traits and proactive aggression. Overall, a possible explanation of our divergent findings between conscious and automatic fear may be the difference between the instinctual biological response to threat versus the cognitive and emotional appraisal and experience of threat. Implications for intervention strategies targeting emotional recognition and regulation in reducing aggression in CD populations are discussed.

Is childhood lying shaped by callous-unemotional traits or does lie-telling make children more callous-unemotional? A longitudinal between- and within-person perspective.

The current study aims to advance knowledge on the causal interrelationship between childhood CU traits and lying both at a between- and a within-person perspective across a significant developmental period of mid-childhood to mid-adolescence. Cross-lagged panel models and Random-intercept cross-lagged panel models were used to investigate the prospective associations between lying and the distinct subcomponents of CU traits, including Callousness, Uncaring, and Unemotional in a sample of 719 children (T1; Mage = 10.73 years, SDage = 1.38, range = 7-15 years, 54.4% girls) across four assessment points. Results supported large vulnerability effects at the between-person level across time, indicating that CU traits predominantly influence the subsequent development of lying, with Callousness and Uncaring showing most profound effects on subsequent developmental processes of lying. At the within-person level, fluctuations in CU traits and lying were overall meaningfully related, but no causal relationship could be empirically determined. These findings provide a differentiated etiological viewpoint on the intertwinement of CU traits and lying at a young age, and underscore the importance of an early identification of children with callous and uncaring tendencies in order to prevent more persistent lying in adolescence.

Deficits in emotion recognition and processing in children with high callous-unemotional traits: the role of the MAOA gene.

Children with high Callous-Unemotional (CU) traits show deficits in recognizing and processing facial expressions. Alterations in emotion recognition have been linked to a higher synaptic concentration of monoaminergic neurotransmitters. The current study investigated the relationship between the MAOA-Low-activity alleles and the ability to recognize and process facial expressions in 97 male children (8-12years old) diagnosed with disruptive behavior disorder. Participants completed a computerized emotion-recognition task while an eye-tracking system recorded the number (Fixation Count, FC) and length (Fixation Duration, FD) of fixations to the eye region of the emotional stimuli. Children with high CU traits exhibited lower scores in recognition of sadness and anger, and lower FC and FD for sadness and fear than children with low CU traits. Children carrying the MAOA-Low-activity alleles displayed lower FD for sadness, and FD and FC for fear than those carrying the MAOA-High-activity alleles. These genetic effects appeared even stronger in children with CU traits. Moderation analysis revealed that CU traits were associated with lower FC and FD for fear, and lower FD for sadness, probably due to the MAOA-Low-activity alleles. Our findings, although to be replicated, suggest MAOA-Low-activity alleles as potential genetic biomarkers to identify CU children in need of training focused on emotion processing.

Primary and Secondary Variants of Callous-Unemotional Traits in Community Youths: Differences in Anticipatory Fear.

Callous-unemotional (CU) traits refer to a cluster of characteristics such as low empathy, lack of remorse, and insensitivity to the emotions of others, delineating a group of youth at high risk for severe antisocial behavior. Two variants-primary and secondary CU-have been theorized to have different underlying mechanisms, although mixed findings have been reported. The current study examined if the variants differ in their level of anticipatory fear in 92 youths from the community (mean age = 14.2 years, range = 12.3-16.4 years; 43.5% female). Participants completed a countdown task while their heart rate and skin conductance responses were recorded. Parents and youths completed the inventory of callous-unemotional traits and the child behavior checklist. Compared to the control group (low CU/low anxiety), the primary CU group (high CU/low anxiety) showed prolonged heart rate deceleration in anticipation of the impending aversive stimulus. The secondary CU group (high CU/high anxiety) did not differ from the other two groups on heart rate or skin conductance responses. This prolonged heart rate deceleration in the primary CU group is interpreted in the context of the passive vagal coping theory of antisocial behavior which hypothesizes that an over-engagement of the parasympathetic nervous system reduces the impact of a socializing punishment, which in turn predisposes individuals to antisocial behavior. Findings provide further support for the distinct etiology of two variants of CU traits.