Respiratory sinus arrhythmia and heart period in infancy as correlates of later oppositional defiant and callous-unemotional behaviors

Parasympathetic Nervous System Functioning Moderates the Associations between Callous-Unemotional Traits and Emotion Understanding Difficulties in Late Childhood

BACKGROUND

Callous-unemotional (CU) traits are characterized by low empathy, guilt, and prosociality, putting children at risk for lifespan antisocial behavior. Elevated CU traits have been linked separately to difficulties with emotion understanding (i.e., identifying emotional states of others) and disrupted parasympathetic nervous system (PNS) functioning. However, no study has investigated how PNS functioning and emotion understanding are jointly related to CU traits.

METHOD

We explored associations between CU traits, emotion understanding, and PNS functioning (indexed via respiratory sinus arrhythmia [RSA]) among children aged 7-10 years old (n = 55). We also tested whether deficits in emotion understanding differ across specific emotions (i.e., fear, pain, happiness, anger). Each child's RSA was continuously recorded while they watched a film that included emotionally evocative social interactions. To assess emotion understanding, children identified emotions replayed in 1s animations of scenes from the film. Parents reported on child CU traits, conduct problems, and demographic information.

RESULTS

Higher CU traits were related to lower emotion understanding (β = -0.43, p = 0.03). PNS activity during the film moderated this association (β = -0.47, p < 0.001), such that CU traits were associated with lower emotion understanding among children with mean (B = -0.01, t = -2.46, p = 0.02) or high (i.e., 1 SD > M; B = -0.02, t = -3.00, p < 0.001) RSA levels during the film, but not among children with low RSA levels (i.e., 1 SD < M; B = 0.00, t = -0.53, p = 0.60). Moreover, we found that the observed moderated associations are driven by deficits in fear, specifically.

CONCLUSIONS

The link between poorer emotion understanding, fear understanding in particular, and CU traits was attenuated for children who demonstrated patterns of PNS functioning consistent with attentional engagement while viewing the emotion stimuli.

EgoActive: Integrated Wireless Wearable Sensors for Capturing Infant Egocentric Auditory-Visual Statistics and Autonomic Nervous System Function 'in the Wild'

There have been sustained efforts toward using naturalistic methods in developmental science to measure infant behaviors in the real world from an egocentric perspective because statistical regularities in the environment can shape and be shaped by the developing infant. However, there is no user-friendly and unobtrusive technology to densely and reliably sample life in the wild. To address this gap, we present the design, implementation and validation of the EgoActive platform, which addresses limitations of existing wearable technologies for developmental research. EgoActive records the active infants' egocentric perspective of the world via a miniature wireless head-mounted camera concurrently with their physiological responses to this input via a lightweight, wireless ECG/acceleration sensor. We also provide software tools to facilitate data analyses. Our validation studies showed that the cameras and body sensors performed well. Families also reported that the platform was comfortable, easy to use and operate, and did not interfere with daily activities. The synchronized multimodal data from the EgoActive platform can help tease apart complex processes that are important for child development to further our understanding of areas ranging from executive function to emotion processing and social learning.

Some critical considerations in applying the construct of psychopathy to research and classification of childhood disruptive behavior disorders

The recent inclusion of callous-unemotional traits in the diagnostic criteria for serious conduct problems has led to renewed interest in more comprehensive integrations of the construct of psychopathy into research and clinical classification of childhood disruptive behavior disorders. There have been a number of recent reviews of research focusing the many potential benefits for this integration. However, there are also a number of issues that could reduce these benefits and even potentially lead to harmful effects. The current paper focuses on several of these issues, some of which are common when attempting to integrate research findings across areas that have been conducted independently of each other. Other issues are more specific to the construct of psychopathy. Specifically, the current paper focuses on the lack of agreement on the necessary and sufficient dimensions needed to define psychopathy, the need to consider developmental relationships among these dimensions, the implications of the different associations among the dimensions of psychopathy with conduct problems in children and adolescents, the need to consider how these dimensions relate to existing constructs used in the classification of disruptive behavior disorders, and the potential harmful effects of labeling something "a dimension of psychopathy". These issues have several clear implications for using the construct of psychopathy to guide research on and diagnostic classification of childhood disruptive behavior disorders.

Links between Oppositional Defiant Disorder Dimensions, Psychophysiology, and Interpersonal versus Non-interpersonal Trauma

The etiology of oppositional defiant disorder (ODD) is not well understood but appears to have both biologically-based roots and can develop following adverse experiences. The current study is the first to examine the interaction between biologically-based factors and type of trauma experience (i.e., interpersonal and non-interpersonal) and associations with ODD. The psychophysiological factors included baseline resting heart rate, respiratory sinus arrhythmia (RSA), and cortisol. ODD was measured as two dimensions of irritable and defiant/vindictive. The sample included 330 children, 3-7 years-old, oversampled for a history of trauma. Results showed the interactions between baseline physiological arousal variables and trauma type in predicting ODD dimensions were not supported. However, the baseline RSA by trauma interaction was a significant predictor of defiance/vindictiveness among boys, but not girls, when interpersonal trauma was compared to controls. Several other gender differences emerged. Among boys, both interpersonal and non-interpersonal trauma were predictive of ODD dimensions; however, among girls, non-interpersonal trauma was not. Among girls, there was a significant negative bivariate relationship between baseline cortisol and irritability. Also, when the sample was restricted to those with interpersonal trauma only and controls, baseline RSA was negatively associated with irritability in girls only (controlling for trauma). Finally, retrospective reports revealed that children who met criteria for ODD diagnosis and experienced interpersonal trauma were more likely to exhibit ODD symptoms prior to their trauma compared to those who experienced non-interpersonal trauma. Results are discussed in the context of previous mixed findings, and avenues for future research are highlighted.

Characterizing change in vagal tone during the first three years of life: A systematic review and empirical examination across two longitudinal samples

Functioning of the parasympathetic nervous system (PNS), most often indexed by respiratory sinus arrhythmia (RSA), influences the volitional, cognitively-mediated forms of self-regulation across development. However, despite its clear relevance to children's self-regulation, and its utility as a transdiagnostic biomarker of emotion dysregulation and psychopathology, the ontogeny of vagal tone under conditions of homeostasis across infancy and early childhood is not well understood. The current research is comprised of two complementary studies. The first aims to address this gap by conducting a systematic review of the literature which has assessed resting RSA in the first three years of life. The second study uses data from two diverse, longitudinal datasets (n = 203 and n = 370) to model change in RSA from infancy to toddlerhood. Results from a systematic review of 62 studies meeting inclusion criteria suggest that measures of resting RSA increase over time and demonstrate moderate stability across infancy, toddlerhood, and preschool ages. Results from a series of models fit to longitudinal data in study two suggest that baseline RSA is characterized by stable increases across infancy and early childhood. Moreover, although there was equivocal evidence for individual variability in trajectories of RSA, the findings suggest that the individual differences in resting RSA may become entrenched in early life based on observed significant variance in growth model intercepts. In all, the current study contributes to our understanding of the developmental trajectories of baseline RSA across infancy and early childhood and should support future research examining links between children's parasympathetic regulation and their adjustment in early life.

Autonomic Nervous System Inflexibility During Parent-child Interactions is Related to Callous-unemotional Traits in Youth Aged 10-14 Years Old

Youth with callous-unemotional (CU) traits are at high risk for aggression and antisocial behavior. Extant literature suggests that CU traits are related to abnormal autonomic responses to negatively-valenced emotional stimuli, although few studies have tested autonomic responding specifically during social interactions. To address this knowledge gap, the current study tested whether CU traits were related to autonomic activity, assessed via respiratory sinus arrhythmia (RSA), during several parent-child interaction tasks designed to provoke negative emotion. The sample was 162 clinically referred youth (M age = 12.03, SD = .92; 47% female). Using piecewise latent growth models, we estimated individual differences in RSA during three semi-structured social interaction tasks (reading aloud to a parent and research assistant; a recovery period from the reading task; and a parent-child conflict discussion) and tested whether CU traits were related to patterns of RSA responding across tasks. Overall, youth showed expected RSA decreases during the reading period, increases in RSA during recovery, and further decreases during the conflict discussion. However, youth with clinically-elevated CU traits had a different pattern of RSA change across tasks, such that CU traits were related to significantly less RSA change during reading and recovery. Findings suggest that less RSA engagement during social interactions and less RSA recovery may be a biomarker of CU traits. Future research is needed to examine whether this inflexibility contributes to the development of CU traits beginning early in childhood.

Observed Peer Competence Moderates Links between Children's Self-Regulation Skills and Academic Performance

The current study focuses on the relations between observed measures of children's self-regulation and academic achievement, as well as the extent to which observations of children's peer competence in preschool moderates these links. Data were drawn from 102 students (male = 48; M _age = 4.82 years, SD _age = 0.46 years) enrolled in pre-kindergarten classrooms. A series of linear path models was used to test study hypotheses, and the nature of significant interactions was elucidated by examining simple slopes and regions of significance. Children's self-regulation, but not peer competence, significantly predicted both reading and math performance assessed using the Woodcock Johnson III, β = .43, p < .001 and β = .39, p < .001, respectively. Tests of moderation effects revealed that the association between children's poor self-regulation and poor math performance, but not reading performance, β = -.28, p = .022 and β = -.11, p = .23, was negated for children with average to high peer competence. These results demonstrate the protective quality of peer competence for academic performance using observational methods collected in preschools.

An autonomic nervous system context of harsh parenting and youth aggression versus delinquency

Harsh parenting is a significant predictor of youth aggression and delinquency. However, not every child exposed to adverse parenting develops such problem behaviors. Recent developmental evolutionary models suggest that variability in stress response reactivity to parenting, reflected by autonomic nervous system (ANS) functioning, may affect the impact of adverse parenting on youth behavioral adjustment. The aim of the present study was to investigate whether the parasympathetic and sympathetic branches of the ANS moderate the association between parenting and aggressive and delinquent behaviors. The study sample included low-income, ethnically diverse preadolescents (M = 10.28 years old; N = 101) and their caregivers. Direct effects were found from basal RSA to delinquent behaviors. In addition, harsh parenting predicted increased youths' aggressive and delinquent behaviors in the context of high RSA withdrawal and increased youths' delinquent behaviors in the context of shortened basal PEP. Implications for prevention and intervention are discussed.

Associations Between Callous-Unemotional Traits and Peer-Rated Social-Behavioral Outcomes in Elementary and Middle School

There is strong evidence that peers are of central importance to children's and adolescents' social and emotional adaptation and success in school. However, it remains an open question as to whether callous-unemotional (CU) traits, or interpersonal and affective deficits that pose risk for antisocial behaviors and psychopathy, are related to social-behavioral outcomes as assessed by those who are believed to have the most accurate perspectives on such outcomes - young adolescents' peers. Using data from a longitudinal and multi-method study of peer relations (N = 379, % female = 51.90, M_age = 10.24 at Time 1), the current study addressed this gap by examining the links between teacher-reports of CU traits and conduct problems (CP) and peer-reports of the extent to which young adolescents are aggressive, victimized, excluded, prosocial, and sociable during the Fall and Spring semesters in Grade 5 (Times 1and 2) and Grade 6 (Times 3 and 4). Results revealed that teacher-rated CP, but not CU traits, was associated positively with peer-reports of aggression. CU traits, but not CP, was associated positively with victimization/exclusion and associated negatively with prosociality. CU traits and CP demonstrated opposite relations with sociability, with CU traits demonstrating a negative association. Findings are discussed in the context of the broader literature examining the social-behavioral correlates of CU traits.

The relationship between resting heart rate and aggression in males is racially variant

Although resting heart rate is thought to be a generalizable risk factor for aggression, very little research has examined whether this relationship varies by race. We addressed this limitation using longitudinal data from the Pittsburgh Youth Study. Current data are from 197 men who participated in a teenage biosocial study (mean age = 15.7 years) and adult follow-up study (mean age = 32.1 years). Teenage resting heart rate interacted with race to predict teenage and adult aggression. The relationship between heart rate and aggression was significant in White, but not in Black males. To our knowledge, this is the first study to find that the relationship between resting heart rate and aggression is racially variant, suggesting that resting heart rate may not be a generalizable biomarker for conduct problems. At an intervention-level, findings could contribute to the development of more accurate risk assessment tools that take into account racial variance in risk factors.

Respiratory Sinus Arrhythmia Mediates Links Between Borderline Personality Disorder Symptoms and Both Aggressive and Violent Behavior

Although emotion dysregulation (ED) is a core symptom of borderline personality disorder (BPD), tests of associations between ED and aggression and violence-which are common to BPD-are sparse. The authors evaluated mediating effects of an autonomic vulnerability to ED on links between BPD symptoms and (a) reactive aggression, (b) proactive aggression, and (c) histories of interpersonal violence in a sample of young adults (N = 104), ages 18-22 years. Low baseline respiratory sinus arrhythmia (RSA) mediated the association between BPD symptoms and reactive aggression. In contrast, although BPD symptoms were correlated with proactive aggression, no mediational effect was found. In addition, low RSA mediated the association between BPD symptoms and histories of interpersonal violence. Collectively, these findings add evidence that neurobiological vulnerability to ED contributes to aggressive and violent behavior among those with BPD.

Parenting and Cortisol in Infancy Interactively Predict Conduct Problems and Callous-Unemotional Behaviors in Childhood

This study examines observed maternal sensitivity, harsh-intrusion, and mental-state talk in infancy as predictors of conduct problems (CP) and callous-unemotional (CU) behaviors in middle childhood, as well as the extent to which infants' resting cortisol and cortisol reactivity moderate these associations. Using data from the Family Life Project (n = 1,292), results indicate that maternal sensitivity at 6 months predicts fewer CP at first grade, but only for infants who demonstrate high levels of cortisol reactivity. Maternal harsh intrusion predicts fewer empathic-prosocial behaviors, a component of CU behaviors, but only for infants who demonstrate high resting cortisol. Findings are discussed in the context of diathesis-stress and differential susceptibility models.

Early life predictors of callous-unemotional and psychopathic traits

Psychopathy is a disorder that occurs primarily in males. Offenders with psychopathic traits are responsible for a disproportionate amount of crime in society, particularly violent crime. Early childhood is a time when individual differences in empathy and guilt-key indicators of the construct of psychopathy-are first evident. A growing number of longitudinal studies have begun to investigate how factors in infancy and early childhood predict psychopathic-like traits in later childhood, adolescence, and adulthood. These studies have suggested that parenting styles during infancy (parental sensitivity, maternal harsh intrusion, commenting on the emotional state of the child) as well as attachment styles are predictive of later psychopathic-like traits. In addition, child characteristics such as temperament and the functioning of biological systems such as the autonomic nervous system and hypothalamic-pituitary-adrenal axis are predictive. Overall, studies have suggested that at least some of the origins of psychopathic traits are present in infancy and early childhood, which is consistent with the perspective of psychopathy as a neurodevelopmental disorder. A recent evolutionary-developmental model provides hypotheses regarding how psychopathy may develop and why it is more common in males than females. This model, and its implications for intervention, is discussed in the context of the longitudinal studies that have been conducted on psychopathy.

Children's autonomic functioning moderates links between maternal rejecting attitudes and preschool aggressive behaviors

Substantial theoretical and empirical literature suggests that the extent to which children's early experiences contribute to the development of aggressive behaviors may depend on the psychophysiological regulatory capacities of the child. This study adds to this literature by examining the relations between mothers' rejecting child-rearing attitudes and children's aggressive behaviors, as well as whether children's parasympathetic regulation, both at rest and in response to anger-inducing films, moderate these links. Using the data collected from 88 preschoolers (mage  = 51 months), the results revealed that the positive association between mothers' rejecting child-rearing attitudes and children's aggressive behaviors was moderated by respiratory sinus arrhythmia (RSA) reactivity to anger. More rejecting child-rearing attitudes predicted more aggressive behaviors only for children who showed mild RSA suppression to RSA augmentation. Conversely, and consistent with the differential-susceptibility model, children who showed mild RSA suppression to RSA augmentation had the fewest aggressive behaviors when mothers reported less rejecting child-rearing attitudes.

Callous-unemotional behaviors in early childhood: the development of empathy and prosociality gone awry

Callous-unemotional (CU) behaviors are critical to understanding the development of severe forms of aggression and antisocial behavior. CU behaviors include deficits in empathy and prosocial behavior, as well as reduced interpersonal responsivity to others. We review recent research examining CU behaviors in early childhood and the role that parents play in the development of early CU behaviors. We integrate research on the development of empathy and prosociality with that of CU behaviors to propose a developmental model of early CU behaviors that considers person-by-context interactions.

Proactive and Reactive Aggression Subgroups in Typically Developing Children: The Role of Executive Functioning, Psychophysiology, and Psychopathy

This study aimed to assess whether groups of aggressive children differed on psychopathic traits, and neuropsychological and neurobiological measures of prefrontal functioning consistent with the objectives of their aggression-reactive or proactive. Including 110 typically developing children (9-11 years), a latent class analysis identified a low aggression group, a high reactive aggression group, and a mixed (high reactive and proactive) aggression group. Results show high callous-unemotional traits and low resting respiratory sinus arrhythmia increased the likelihood of children being in the mixed aggression group, when compared to the reactive and low aggression groups. However, deficits in planning and inhibitory control increased the likelihood of children being in the reactive aggression group, when compared to the mixed and low aggression groups. Executive functioning deficits did not differentiate the mixed group from the low aggression group. These findings highlight psychobiological and executive functioning differences that may explain heterogeneity in childhood aggression.

Associations between Infant Behaviors during the Face-To-Face Still-Face Paradigm and Oppositional Defiant and Callous-Unemotional Behaviors in Early Childhood

Deficits in social orienting (i.e., gazing toward caregivers) during dyadic interactions and reactivity to stressful stimuli have been identified as behavioral correlates of oppositional defiant disorder (ODD) and callous-unemotional (CU) behaviors in older children. The goal of the current study was to investigate infants' mother-directed gaze and reactivity during the face-to-face and still-face episodes of the face-to-face stillface paradigm performed at 6 months in the prediction of ODD and CU behaviors in early childhood. Using data from the Durham Child Health and Development study (n = 206), hierarchical regression analyses revealed that infants' negative reactivity during the still-face episode and mother-directed gaze during the face-to-face episode predicted fewer ODD behaviors in early childhood. Examination of interaction effects suggested that mother-directed gaze attenuated the negative relation between reactivity and ODD and CU behaviors in early childhood. The current study is one of the first to extend downward the investigation of ODD and CU behaviors into infancy.

Callous-Unemotional Behaviors in Early Childhood: Measurement, Meaning, and the Influence of Parenting

Antisocial behavior is costly and harmful to families, communities, and society. With roots in early childhood, antisocial behavior puts children at risk for poor physical and mental health outcomes across development. Callous-unemotional (CU) traits identify a subgroup of youth with particularly severe and stable antisocial behavior. While much literature has examined CU traits in late childhood and adolescence, researchers are just beginning to elucidate the developmental origins of CU traits. In this article, we review research examining the measurement and correlates of CU behaviors in early childhood, along with evidence that these early behaviors predict later measures of CU traits. We then describe research highlighting the role that parents play in the development of CU behaviors in early childhood. Finally, we outline translational implications and ethical considerations for studying CU behaviors and consider the use of the term CU traits in young children.