Understanding emotion dysregulation from infancy to toddlerhood with a multilevel perspective: The buffering effect of maternal sensitivity

Challenges with childhood emotion regulation may have origins in infancy and forecast later social and cognitive developmental delays, academic difficulties, and psychopathology. This study tested whether markers of emotion dysregulation in infancy predict emotion dysregulation in toddlerhood, and whether those associations depended on maternal sensitivity. When children (N = 111) were 7 months, baseline respiratory sinus arrhythmia (RSA), RSA withdrawal, and distress were collected during the Still Face Paradigm (SFP). Mothers' reports of infant regulation and orientation and maternal sensitivity were also collected at that time. Mothers' reports of toddlers' dysregulation were collected at 18 months. A set of hierarchical regressions indicated that low baseline RSA and less change in RSA from baseline to stressor predicted greater dysregulation at 18 months, but only for infants who experienced low maternal sensitivity. Baseline RSA and RSA withdrawal were not significantly associated with later dysregulation for infants with highly sensitive mothers. Infants who exhibited low distress during the SFP and who had lower regulatory and orienting abilities at 7 months had higher dysregulation at 18 months regardless of maternal sensitivity. Altogether, these results suggest that risk for dysregulation in toddlerhood has biobehavioral origins in infancy but may be buffered by sensitive caregiving.

Temperament and sex as moderating factors of the effects of exposure to maternal depression on telomere length in early childhood

Individual differences in sensitivity to context are posited to emerge early in development and to influence the effects of environmental exposures on a range of developmental outcomes. The goal of the current study was to examine the hypothesis that temperament characteristics and biological sex confer differential vulnerability to the effects of exposure to maternal depression on telomere length in early childhood. Telomere length has emerged as a potentially important biomarker of current and future health, with possible mechanistic involvement in the onset of various disease states. Participants comprised a community sample of children followed from infancy to age 3 years. Relative telomere length was assessed from DNA in saliva samples collected at infancy, 2 years, and 3 years. Maternal depressive symptoms and the child temperament traits of negative affectivity, surgency/extraversion, and regulation/effortful control were assessed via maternal report at each timepoint. Analyses revealed a 3-way interaction among surgency/extraversion, sex, and maternal depressive symptoms, such that higher surgency/extraversion was associated with shorter telomere length specifically among males exposed to elevated maternal depressive symptoms. These findings suggest that temperament and sex influence children's susceptibility to the effects of maternal depression on telomere dynamics in early life.

Preliminary Technical Validation of LittleBeats™: A Multimodal Sensing Platform to Capture Cardiac Physiology, Motion, and Vocalizations

Across five studies, we present the preliminary technical validation of an infant-wearable platform, LittleBeats™, that integrates electrocardiogram (ECG), inertial measurement unit (IMU), and audio sensors. Each sensor modality is validated against data from gold-standard equipment using established algorithms and laboratory tasks. Interbeat interval (IBI) data obtained from the LittleBeats™ ECG sensor indicate acceptable mean absolute percent error rates for both adults (Study 1, N = 16) and infants (Study 2, N = 5) across low- and high-challenge sessions and expected patterns of change in respiratory sinus arrythmia (RSA). For automated activity recognition (upright vs. walk vs. glide vs. squat) using accelerometer data from the LittleBeats™ IMU (Study 3, N = 12 adults), performance was good to excellent, with smartphone (industry standard) data outperforming LittleBeats™ by less than 4 percentage points. Speech emotion recognition (Study 4, N = 8 adults) applied to LittleBeats™ versus smartphone audio data indicated a comparable performance, with no significant difference in error rates. On an automatic speech recognition task (Study 5, N = 12 adults), the best performing algorithm yielded relatively low word error rates, although LittleBeats™ (4.16%) versus smartphone (2.73%) error rates were somewhat higher. Together, these validation studies indicate that LittleBeats™ sensors yield a data quality that is largely comparable to those obtained from gold-standard devices and established protocols used in prior research.

The significance of mothers' attachment representations for vagal responding during interactions with infants

Little is known about the significance of mothers' attachment for neurobiological responding during interactions with infants. To address this gap, this study examined links between mothers' (N = 139) attachment representations and dynamic change in respiratory sinus arrhythmia (RSA) while interacting with infants in the Still-Face Procedure (SFP). Mothers higher on secure base script knowledge (SBSK) exhibited greater RSA reactivity during the SFP characterized by lower RSA during normal play, higher RSA during the still-face, and lower RSA during reunion. Findings indicate that mothers higher on SBSK exhibit RSA responding expected to support active behavioral coping during normal play and reunion - consistent with the need to engage infants in social interaction - and RSA responding during the still-face expected to support efforts to calm the body and empathize with their infant during this distressing social disruption. Findings advance knowledge of the significance of adult attachment for the neurobiology of caregiving.

"Katerina gets mad": Infants' physiological and behavioral responses to co-viewing educational, self-regulatory media

A growing body of research has focused on the physiological impact of media on older children and adolescents. Less research has been focused on the potential physiological impact of media on infants and younger children, especially media designed to be age appropriate and educational in content. In this study, we examined respiratory sinus arrhythmia (RSA) in infants (N = 269, M_age  = 17.13 months) while they co-viewed an educational video clip that modeled emotion regulation and contrasted their physiological response to an unoccupied baseline and a frustration paradigm (arm-restraint). Given parent reports showing the calming effect of educational media viewing in young children, we anticipated that a similar pattern of calming would be observed physiologically in infants. Results showed that relative to baseline, most infants demonstrated an increase in RSA while co-viewing, suggesting greater parasympathetic (regulatory) activation consistent with behavioral calming. However, infants who demonstrated vagal withdrawal during co-viewing (decrease in RSA) were more likely to have parents who used a tablet to help infants go to sleep at night. Vagal withdrawal was also associated with increased levels of negative affect observed during the co-viewing task. Findings are discussed in relation to the contextual effect of co-viewing age-appropriate, educational media on children's physiological responses.

Temperamental and physiological regulatory capacity in infancy: Links with toddler behavior problems

Although correlates of temperamental regulatory processes in childhood have been well established, there is considerably less work examining correlates and moderators of rudimentary forms of temperamental regulation in infancy. We examined whether infants' physiological regulation indexed via changes in respiratory sinus arrhythmia (RSA) across phases of the Still-Face Paradigm moderated the association between maternal-reported infant regulatory capacity at 8 months (N = 50, M_age = 8.51 months, SD_age = 0.28 months, 25 girls) and behavior problems at 14 months. We found that cardiac vagal regulation from baseline to still-face moderated the relation between infant regulatory capacity at 8 months and behavior problems at 14 months. Among infants who displayed relatively high cardiac vagal regulation from baseline to still-face, regulatory capacity was negatively associated with behavior problems. There was no relation between regulatory capacity and behavior problems among infants who displayed average or relatively low cardiac vagal regulation. We speculate that high levels of regulatory capacity and cardiac vagal regulation may allow infants to focus their attention outward and cope with emotionally evocative environmental demands as they arise even in the absence of external regulation provided by their caregivers.

Examining Links Between Infant Parasympathetic Regulation during the Still-Face Paradigm and Later Callous-Unemotional Traits

Although research suggests that callous-unemotional (CU) traits are underpinned by deficits in social affiliation and reduced sensitivity to threat, there has been little investigation of the biophysiological regulatory mechanisms underlying these processes in infancy. The current study uses data from the Durham Child Health and Development Study (DCHD; n = 206) to examine whether and how the combination of infants' behavioral reactivity and levels of respiratory sinus arrhythmia (RSA), an indicator of parasympathetic nervous system functioning, during the still-face episode of the still-face paradigm at 6 months differentiates risk for CU traits and oppositional defiant behaviors (ODD) at age 3 years, as well as whether these relations vary by children's attachment security. Results indicate that reduced negative affect during the still-face episode at 6 months predicts higher CU traits (B = -0.28, β = -0.27, p = 0.003) and ODD (B = -0.35, β = -0.24, p = 0.007) at 3 years. Results also show that comparatively lower RSA, i.e. engaged parasympathetic system, predicts higher CU traits (B = -0.10, β = -0.34, p = 0.013), but not ODD. Tests of moderation suggest the combination of blunted negative affect but comparatively lower RSA levels during a social stressor constitutes risk for later CU traits for children who are also insecurely attached (simple slope = -0.70, t = 2.88, p = 0.006 at -1 SD). Findings contribute to our understanding of the complex and interactive risk processes which precede the development of CU traits.

Action Understanding Promoted by Interoception in Children: A Developmental Model

Action understanding of children develops from simple associative learning to mentalizing. With the rise of embodied cognition, the role of interoception in action observation and action understanding has received more attention. From a developmental perspective, this study proposes a novel developmental model that explores how interoception promotes action understanding of children across ages. In early infancy, most actions observed in infants come from interactions with their caregivers. Babies learn about action effects through automatic interoceptive processing and interoceptive feedback. Interoception in early infancy is not fully developed, such as the not fully developed gastrointestinal tract and intestinal nervous system. Therefore, in early infancy, action understanding is based on low-level and original interoceptive information. At this stage, after observing the actions of others, infants can create mental representations or even imitate actions without external visual feedback, which requires interoception to provide internal reference information. By early childhood, children begin to infer action intentions of other people by integrating various types of information to reach the mentalizing level. Interoception processing requires the integration of multiple internal signals, which promotes the information integration ability of children. Interoception also provides inner information for reasoning about action intention. This review also discussed the neural mechanisms of interoception and possible ways by which it could promote action understanding of children. In early infancy, the central autonomic neural network (CAN) automatically processes and responds to the actions of caregivers on infants, providing interoceptive information for action understanding of infants. In infancy, the growth of the somatomotor system provides important internal reference information for observing and imitating the actions of infants. In early childhood, the development of interoception of children facilitates the integration of internal and external information, which promotes the mentalization of action understanding of children. According to the proposed developmental model of action understanding of children promoted by interoception, there are multilevel and stage-dependent characteristics that impact the role of interoception in action understanding of children.

Associations between infant-mother physiological synchrony and 4- and 6-month-old infants' emotion regulation

In this study we assessed whether physiological synchrony between infants and mothers contributes to infants' emotion regulation following a mild social stressor. Infants between 4 and 6 months of age and their mothers were tested in the face-to-face-still-face paradigm and were assessed for behavioral and physiological self-regulation during and following the stressor. Physiological synchrony was calculated from a continuous measure of respiratory sinus arrhythmia (RSA) enabling us to cross-correlate the infants' and mothers' RSA responses. Without considering physiological synchrony, the evidence suggested that infants' distress followed the prototypical pattern of increasing during the Still Face episode and then decreasing during the reunion episode. Once physiological synchrony was added to the model, we observed that infants' emotion regulation improved if mother-infant synchrony was positive, but not if it was negative. This result was qualified further by whether or not infants suppressed their RSA response during the Still Face episode. In sum, these findings highlight how individual differences in infants' physiological responses contribute significantly to their self-regulation abilities.

Parasympathetic response to challenge in infancy moderates the effects of sociodemographic risk on academic achievement at school entry

Exposure to higher levels of sociodemographic risk is associated with lower levels of academic achievement among young children. However, there is variability in the strength of this association, which may be traced to individual differences in physiological processes underlying self-regulation. In the current study, we examined whether the response of the parasympathetic nervous system to challenge, indexed by change in respiratory sinus arrhythmia (RSA), moderated the association between risk and school readiness at 5 years of age in a diverse sample of young children. We found that parasympathetic response to the Still-Face Paradigm moderated the effects of risk on a measure of school readiness, such that there was no association between risk and school readiness among children who exhibited RSA decreases during challenge at 6 months of age, a purported index of self-regulation at this age. For those infants who did not exhibit RSA withdrawal during this challenge, exposure to early cumulative risk was associated with lower scores on achievement assessment. These results speak to the possibility that certain patterns of parasympathetic response can serve as a protective factor for young children growing up in disadvantaged environments.

An examination of the reciprocal and concurrent relations between behavioral and cardiac indicators of acute pain in toddlerhood

The aim of this study was to examine the concurrent and predictive relations between healthy toddlers' pain behavior and cardiac indicators (ie, heart rate [HR] and respiratory sinus arrhythmia [RSA]) during routine vaccinations. Caregiver-infant dyads were part of a longitudinal cohort observed during their 12- and 18-month vaccinations. Behavioral and cardiac data were simultaneously collected for 1-minute preneedle and 3-minutes postneedle. Videotapes were coded for pain behaviors (FLACC; Merkel et al., 1997), and cardiac data were analyzed (HR, RSA) during sequential 30-second epochs. Four separate cross-lagged path models were estimated using data from the 12- (n = 147) and 18-month (n = 122) vaccinations. Across 12- and 18-month vaccinations, predictive within-measure relations were consistent for FLACC, HR, and RSA, reflecting good stability of these pain indicators. Behavioral indicators predicted subsequent HR and RSA within the immediate postneedle period. Both baseline behavior and HR/RSA predicted future pain scores. Concurrent residual relations between behavioral and cardiac indicators were inconsistent across time and indicators. Results suggest that behavioral and cardiac indicators reflect unique aspects of the nociceptive response. As such, multimodal assessment tools should be used and contextualized by child age, cardiac indicator, baseline behavior/physiology, and pain phase.

Autonomic Nervous System Maturation and Emotional Coordination in Interactions of Preterm and Full-Term Infants With Their Parents: Protocol for a Multimethod Study

Background

There is limited knowledge on the physiological and behavioral pathways that may affect the developmental outcomes of preterm infants and particularly on the link between autonomic nervous system maturation and early social human behavior. Thus, this study attempts to investigate the way heart rate variability (HRV) parameters are related to emotional coordination in interactions of preterm and full-term infants with their parents in the first year of life and the possible correlation with the developmental outcomes of infants at 18 months.

Objective

The first objective is to investigate the relationship between emotional coordination and HRV in dyadic full-term infant–parent (group 1) and preterm infant–parent (group 2) interactions during the first postpartum year. The second objective is to examine the relationship of emotional coordination and HRV in groups 1 and 2 in the first postpartum year with the developmental outcomes of infants at 18 months. The third objective is to investigate the effect of maternal and paternal postnatal depression on the relation between emotional coordination and HRV in the two groups and on developmental outcomes at 18 months. The fourth objective is to examine the effect of family cohesion and coping on the relation between emotional coordination and HRV in the two groups and on developmental outcomes at 18 months.

Methods

This is an observational, naturalistic, and longitudinal study applying a mixed method design that includes the following: (1) video recordings of mother-infant and father-infant interactions at the hospital, in the neonatal period, and at home at 2, 4, 6, 9, and 12 months of the infants’ life; (2) self-report questionnaires of parents on depressive symptoms, family cohesion, and dyadic coping of stress; (3) infants’ HRV parameters in the neonatal period and at each of the above age points during and after infant-parent video recordings; and (4) assessment of toddlers’ social and cognitive development at 18 months through an observational instrument.

Results

The study protocol has been approved by the Research Ethics Committee of the University of Crete (number/date: 170/September 18, 2020). This work is supported by the Special Account for Research Funds of the University of Crete (grant number: 10792-668/08.02.2021). All mothers (with their partners) of full-term and preterm infants who give birth between March 2021 and January 2022 at the General University Hospital of Crete (northern Crete, Greece) will be invited to participate. The researcher will invite the parents of infants to participate in the study 1 to 2 days after birth. Data collection is expected to be completed by March 2023, and the first results will be published by the end of 2023.

Conclusions

Investigating the regulatory role of HRV and social reciprocity in preterm infants may have implications for both medicine and psychology.

International Registered Report Identifier (IRRID)

PRR1-10.2196/28089

Towards an understanding of neurophysiological self-regulation in early childhood: A heuristic and a new approach

Self-regulation in early childhood encompasses both "top down," volitional processes, as well as the "bottom up" activity of three neurophysiological systems: the parasympathetic nervous system (PNS), the sympathetic nervous system (SNS), and the hypothalamic-pituitary-adrenal (HPA) axis. In this paper we briefly review the structure, function, and early development of each of these systems and then explain why neurophysiological self-regulation is most accurately defined as a function of their joint activity. We note that while there are a number of predictive models that employ this definition, the field would benefit from a straightforward heuristic and aligned methods of visualization and analysis. We then present one such heuristic, which we call neurophysiological space, and outline how it may facilitate a new, collaborative approach to building a better understanding of self-regulation in early childhood. We conclude with a presentation of early education as one setting in which our heuristic and methods could be applied.

The Development of Generosity From 4 to 6 Years: Examining Stability and the Biopsychosocial Contributions of Children's Vagal Flexibility and Mothers' Compassion

Individual differences in children’s prosocial behaviors, including their willingness to give up something of value for the benefit of others, are rooted in physiological and environmental processes. In a sample of 4-year-old children, we previously found evidence that flexible changes in respiratory sinus arrhythmia (RSA) were linked to donation behavior, and that these physiological patterns may support greater sensitivity to the positive effects of compassionate parenting on donation behavior. The current study focused on a follow-up assessment of these children at age 6. First, we examined the stability of individual differences in donation behavior and related parasympathetic nervous system (PNS) activity from age 4 to 6. Second, we examined associations between donation behavior and RSA at 6 years. Third, we examined whether the association between children’s RSA and donation behavior at age 6 varied depending on mothers’ compassionate love. We found low to modest stability in donation behavior and RSA reactivity from age 4 to 6. These findings provide preliminary evidence that stable individual differences in altruism, as reflected by generosity, and in some aspects of parasympathetic functioning during opportunities to be prosocial, emerge in childhood. In addition, we found that some of the same associations between donation behavior, RSA, and compassionate love that we previously observed in children at 4 years of age continued to be evident 2 years later at age 6. Greater decreases in RSA when given the opportunity to donate were associated with children donating more of their own resources which, in turn, were associated with greater RSA recovery after the task. Lastly, mothers’ compassionate love was positively associated with donation behavior in children who demonstrated stronger decreases in RSA during the task; compassionate parenting and RSA reactivity may serve as external and internal supports for prosociality that build on each other. Taken together, these findings contribute to the perspectives that individual differences in altruistic behaviors are intrinsically linked to healthy vagal flexibility, and that biopsychosocial approaches provide a useful framework for examining and understanding the environmental and physiological processes underlying these individual differences.

Mothers' self-reported emotion dysregulation: A potentially valid method in the field of infant mental health

In the current study, we evaluated the extent to which mothers reported emotion dysregulation on the Difficulties with Emotion Regulation Questionnaire (DERS) (a) converged with physiological indices of emotion dysregulation while parenting, (b) correlated with maternal sensitivity, and (c) predicted infant attachment disorganization and behavior problems in a sample of 259 mothers and their infants. When infants were 6 months old, mothers' physiological arousal and regulation were measured during parenting tasks and mothers completed the DERS. Maternal sensitivity was observed during distress-eliciting tasks when infants were 6 and 14 months old. Infant attachment disorganization was assessed during the Strange Situation when infants were 14 months old and mothers reported on infants' behavior problems when infants were 27 months old. Mothers who reported greater emotion regulation difficulties were more physiologically dysregulated during stressful parenting tasks and also showed lower levels of maternal sensitivity at 6 months. Mother-reported dysregulation predicted higher likelihood of infant attachment disorganization and more behavior problems. Results suggest that the DERS is a valid measure of maternal emotional dysregulation and may be a useful tool for future research and intervention efforts aimed toward promoting positive parenting and early child adjustment.

Neural and psychophysiological correlates of social communication development: Evidence from sensory processing, motor, cognitive, language and emotional behavioral milestones across infancy

This article presents a literature review focusing on the neural and psychophysiological correlates associated with social communication development in infancy. Studies presenting evidence on infants' brain activity and developments in infant sensory processing, motor, cognitive, language, and emotional abilities are described in regard to the neuropsychophysiological processes underlying the emergence of these specific behavioral milestones and their associations with social communication development. Studies that consider specific age-related characteristics across the infancy period are presented. Evidence suggests that specific neural and physiological signatures accompany age-related social communication development during the first 18 months of life.

Prenatal Exposure to PM2.5 and Cardiac Vagal Tone during Infancy: Findings from a Multiethnic Birth Cohort

BACKGROUND

The autonomic nervous system plays a key role in maintaining homeostasis and responding to external stimuli. In adults, exposure to fine particulate matter (PM2.5) has been associated with reduced heart rate variability (HRV), an indicator of cardiac autonomic control.

OBJECTIVES

Our goal was to investigate the associations of exposure to fine particulate matter (PM2.5) with HRV as an indicator of cardiac autonomic control during early development.

METHODS

We studied 237 maternal-infant pairs in a Boston-based birth cohort. We estimated daily residential PM2.5 using satellite data in combination with land-use regression predictors. In infants at 6 months of age, we measured parasympathetic nervous system (PNS) activity using continuous electrocardiogram monitoring during the Repeated Still-Face Paradigm, an experimental protocol designed to elicit autonomic reactivity in response to maternal interaction and disengagement. We used multivariable linear regression to examine average PM2.5 exposure across pregnancy in relation to PNS withdrawal and activation, indexed by changes in respiration-corrected respiratory sinus arrhythmia (RSAc)-an established metric of HRV that reflects cardiac vagal tone. We examined interactions with infant sex using cross-product terms.

RESULTS

In adjusted models we found that a 1-unit increase in PM2.5 (in micrograms per cubic meter) was associated with a 3.53% decrease in baseline RSAc (95% CI: -6.96, 0.02). In models examining RSAc change between episodes, higher PM2.5 was generally associated with reduced PNS withdrawal during stress and reduced PNS activation during recovery; however, these associations were not statistically significant. We did not observe a significant interaction between PM2.5 and sex.

DISCUSSION

Prenatal exposure to PM2.5 may disrupt cardiac vagal tone during infancy. Future research is needed to replicate these preliminary findings. https://doi.org/10.1289/EHP4434.

Infant Vagal Tone and Maternal Depressive Symptoms: A Bottom-Up Perspective

Children vary in their susceptibility to environmental exposures such as maternal depression, but little is known about how children shape those same environments. When raising an infant with low arousal, mothers at risk of depression may experience decreased parenting self-efficacy and increased depressive symptoms. We evaluated a longitudinal mediated moderation model that hypothesized interactive effects of infant vagal tone (indexed by respiratory sinus arrhythmia [RSA]) and maternal postpartum depressive (PPD) symptoms on maternal depressive symptoms in early childhood via parenting self-efficacy. Among a sample of 322 very low-income Mexican American mother-infant dyads (46% male infants), infant RSA was assessed at 6 weeks of age; mothers (M_age = 27.8, SD = 6.5) reported PPD symptoms every 3 weeks from 6 weeks to 6 months, parenting self-efficacy at 18 and 24 months, and depressive symptoms at 18 and 36 months. Higher PPD symptoms predicted higher maternal depressive symptoms at 36 months, especially among mothers whose infants had lower resting RSA. The interactive effect of PPD symptoms and infant RSA on 36-month depressive symptoms was partially mediated by lower parenting self-efficacy. Lower infant RSA may exacerbate the detrimental effects of PPD symptoms on subsequent maternal well-being via damage to mothers' beliefs in their ability to parent effectively.

Beyond the Bayley: Neurocognitive Assessments of Development During Infancy and Toddlerhood

The use of global, standardized instruments is conventional among clinicians and researchers interested in assessing neurocognitive development. Exclusively relying on these tests for evaluating effects may underestimate or miss specific effects on early cognition. The goal of this review is to identify alternative measures for possible inclusion in future clinical trials and interventions evaluating early neurocognitive development. The domains included for consideration are attention, memory, executive function, language, and socioemotional development. Although domain-based tests are limited, as psychometric properties have not yet been well-established, this review includes tasks and paradigms that have been reliably used across various developmental psychology laboratories.

Infants' Biological Sensitivity to the Effects of Maternal Social Support: Evidence Among Mexican American Families

The identification of infants who are most susceptible to both negative and positive social environments is critical for understanding early behavioral development. This study longitudinally assessed the interactive effects of infant vagal tone (respiratory sinus arrhythmia; RSA) and maternal social support on behavioral problems and competence among 322 low-income Mexican American mother-infant dyads (infants: 54.1% female) and explored sex differences. Infant RSA was calculated from resting HR data at 6 weeks of age. Mothers reported on general social support, partner support, and family support at 6 months, and infant behavioral problems and competence at 1 year. Two-way interactions (RSA × support source) were evaluated to predict behavioral problems and competence, adjusting for covariates. Results indicated higher competence among infants with lower RSA whose mothers reported higher general support or higher partner support. Interactive effects on behavior problems of RSA with maternal partner or family support were only found for female infants: Girls with higher RSA showed more behavior problems when mothers reported low support, but fewer problem levels in the context of high support. Our results suggest that infant RSA is an important moderator of the effects of the early social environment on early development.

Parasympathetic Regulation and Inhibitory Control Predict the Development of Externalizing Problems in Early Childhood

The current report examined the longitudinal relations between cognitive self-regulation, physiological self-regulation, and externalizing problems. At age 4 (n = 98; 49 girls) and 6 (n = 87; 42 girls), children completed the Day-Night task, which taps the inhibitory control dimension of executive function. During the task, cardiac activity was measured and respiratory sinus arrhythmia (RSA) was derived as an index of parasympathetic activity. Mothers reported on externalizing problems. A cross-lagged path model was used to estimate longitudinal predictions while controlling for stability in all constructs over time. Earlier inhibitory control negatively predicted later externalizing problems, but not vice versa. However, RSA reactivity moderated this link; better inhibitory control predicted fewer externalizing problems only when reactivity to the Day-Night task ranged from mild RSA suppression to RSA augmentation. Externalizing problems at 6 years were highest among preschoolers who augmented RSA but showed poor inhibitory control performance, suggesting that risk for psychopathology may be better delineated by viewing self-regulation from an integrated, multi-system perspective.

Polymorphic variation in the SLC5A7 gene influences infant autonomic reactivity and self-regulation: A neurobiological model for ANS stress responsivity and infant temperament

OBJECTIVE

To examine the impact of polymorphic variation in the solute carrier family 5 member 7 (SLC5A7) gene on autonomic nervous system (ANS) reactivity indexed by respiratory sinus arrhythmia (RSA) and heart rate (HR) in infants during a dyadic stressor, as well as maternal report of infant self-regulation. Given evidence of race differences in older individuals, race was specifically examined.

METHODS

RSA and HR were collected from 111 infants during the still-face paradigm (SFP). Mothers completed the Infant Behavior Questionnaire-Revised short-form. Multi-level mixed effects models examined the impact of SLC5A7 genotype on RSA and HR across the SFP. Linear models tested the influence of genotype on the relation between RSA, HR, and maternal report of infant self-regulation.

RESULTS

SLC5A7 genotype significantly predicted RSA stress responsivity (β = -0.023; p = 0.028) and HR stress responsivity (β = 0.004; p = 0.002). T-allele carriers exhibited RSA suppression and HR acceleration in response to stress while G/G homozygotes did not suppress RSA and exhibited less HR acceleration. All infants exhibited modest RSA augmentation and HR deceleration during recovery. Race-stratified analyses revealed that White T-allele carriers drove the overall results for both RSA (β = -0.044; p = 0.007) and HR (β = 0.006; p = 0.008) with no relation between SLC5A7 genotype and RSA or HR in Black infants. Maternal report of infant orienting/regulation was predicted by the interaction of SLC5A7 genotype and both RSA recovery (β = 0.359; p = 0.001) and HR recovery (β = -1.659; p = 0.020). RSA augmentation and HR deceleration during recovery were associated with higher maternal reports of self-regulation among T-allele carriers, a finding again primarily driven by White infants.

CONCLUSIONS

Early in development, genetic contributions to ANS are evident and predict maternal report of infant self-regulation within White infants, consistent with prior literature. The lack of associations in Black infants suggest that race differences in physiological reactivity and self-regulation are emerging during the first year of life potentially providing early evidence of disparities in health risk trajectories.

Sociodemographic risk, parenting, and inhibitory control in early childhood: the role of respiratory sinus arrhythmia

BACKGROUND

Deficits of inhibitory control in early childhood are linked to externalizing behaviors and attention problems. While environmental factors and physiological processes are associated with its etiology, few studies have examined how these factors jointly predict inhibitory control. This study examined whether respiratory sinus arrhythmia (RSA) functioned as a mediator or moderator of both cumulative sociodemographic risk and parenting behaviors on inhibitory control during early childhood.

METHODS

The sample included 206 children and their biological mothers. At 24, 30, and 36 months of child age dyads participated in a series of laboratory visits in which sociodemographic, parenting, and baseline RSA (RSAB) data were collected. Inhibitory control was assessed at 36 months using a gift-wrap delay task.

RESULTS

A series of structural equation models yielded no evidence that RSAB mediated the relations of risk or parenting and inhibitory control. RSAB moderated the effects of risk, such that high-risk children with low RSAB performed more poorly on tasks of inhibitory control, while high-risk children with high RSAB did not.

CONCLUSIONS

These results suggest that higher levels of RSAB may mitigate the influence of environmental risk on the development of inhibitory control early childhood.

Growing a social brain

It has long been assumed that social animals, such as humans, are born with a brain system that has evolved to support social affiliation. However, the evidence does not necessarily support this assumption. Alternatively, social animals can be defined as those who cannot survive alone and rely on members from their group to regulate their ongoing physiology (or allostasis). The rather simple evolutionary constraint of social dependency for survival can be sufficient to make the social environment vitally salient, and to provide the ultimate driving force for socially crafted brain development and learning. In this Perspective, we propose a framework for sociality and specify a set of hypotheses on the mechanisms of social development and underlying neural systems. The theoretical shift proposed here implies that profound human characteristics, including but not limited to sociality, are acquired at an early age, while social interactions provide key wiring instructions that determine brain development.

Cardiac vagal regulation in infancy predicts executive function and social competence in preschool: Indirect effects through language

Parasympathetic nervous system functioning in infancy may serve a foundational role in the development of cognitive and socioemotional skills (Calkins, 2007). In this study (N = 297), we investigated the potential indirect effects of cardiac vagal regulation in infancy on children's executive functioning and social competence in preschool via expressive and receptive language in toddlerhood. Vagal regulation was assessed at 10 months during two attention conditions (social, nonsocial) via task-related changes in respiratory sinus arrhythmia (RSA). A path analysis revealed that decreased RSA from baseline in the nonsocial condition and increased RSA in the social condition were related to larger vocabularies in toddlerhood. Additionally, children's vocabulary sizes were positively related to their executive function and social competence in preschool. Indirect effects from vagal regulation in both contexts to both 4-year outcomes were significant, suggesting that early advances in language may represent a mechanism through which biological functioning in infancy impacts social and cognitive functioning in childhood.

Respiratory sinus arrhythmia: Modeling longitudinal change from 6 weeks to 2 years of age among low-income Mexican Americans

Parasympathetically-mediated heart rate variability (HRV), commonly indexed via respiratory sinus arrhythmia (RSA), is theorized to support the physiological regulation of emotion; however, little is known about the trajectory of change in resting RSA across early development among high-risk populations for whom emotion regulation is crucial. This study characterized resting RSA change from 6 weeks to 2 years of age among 312 low-income Mexican American infants. RSA was assessed longitudinally at 6, 12, 18, 24, 52, 78, and 104 weeks of age. On average, resting RSA increased as infants aged, and this change accelerated over time. There was significant variance between infants in resting RSA at 6 weeks of age, and in the slope, and acceleration of resting RSA change. Intraclass correlation among infants' resting RSA measures was minimal, indicating that resting RSA may not be "trait-like" during infancy. Results characterize early RSA development among a high-risk sample, which can inform theoretical understanding of the development of emotional, and behavioral self-regulation in a high-risk population, as well as efforts to promote wellbeing across early childhood.

Contributions of infant vagal regulation at 1 month to subsequent joint attention abilities

Since birth, humans develop an ability to regulate their inner states and behaviors, when facing demanding situations, in order to restore calmness and engage with other persons and the surrounding environment. The present study analyzed whether 1-month infant vagal regulation to auditory stimuli was associated with later joint attention abilities-responding to and initiating joint attention-in interaction with their mothers. Twenty-three infants were assessed and measures of respiratory sinus arrhythmia-RSA (baseline and vagal tone change during auditory stimulation) were used as index of vagal regulation. At 12-months, joint attention behaviors were assessed in a 10-min toy-play mother-infant interaction. Correlational analyses showed that lower baseline RSA and larger increases in vagal tone during auditory stimulation were related to more instances of joint attention behaviors at 12 months, especially responding to joint attention. Results suggest that distinct profiles of autonomic functioning may contribute to joint attention skills.

Neurobiology of culturally common maternal responses to infant cry

This report coordinates assessments of five types of behavioral responses in new mothers to their own infants' cries with neurobiological responses in new mothers to their own infants' cries and in experienced mothers and inexperienced nonmothers to infant cries and other emotional and control sounds. We found that 684 new primipara mothers in 11 countries (Argentina, Belgium, Brazil, Cameroon, France, Kenya, Israel, Italy, Japan, South Korea, and the United States) preferentially responded to their infants' vocalizing distress by picking up and holding and by talking to their infants, as opposed to displaying affection, distracting, or nurturing. Complementary functional magnetic resonance imaging (fMRI) analyses of brain responses to their own infants' cries in 43 new primipara US mothers revealed enhanced activity in concordant brain territories linked to the intention to move and to speak, to process auditory stimulation, and to caregive [supplementary motor area (SMA), inferior frontal regions, superior temporal regions, midbrain, and striatum]. Further, fMRI brain responses to infant cries in 50 Chinese and Italian mothers replicated, extended, and, through parcellation, refined the results. Brains of inexperienced nonmothers activated differently. Culturally common responses to own infant cry coupled with corresponding fMRI findings to own infant and to generic infant cries identified specific, common, and automatic caregiving reactions in mothers to infant vocal expressions of distress and point to their putative neurobiological bases. Candidate behaviors embedded in the nervous systems of human caregivers lie at the intersection of evolutionary biology and developmental cultural psychology.

Quantifying respiratory sinus arrhythmia: Effects of misspecifying breathing frequencies across development

Low resting respiratory sinus arrhythmia (RSA), and to a lesser extent excessive RSA reactivity to emotion evocation, are observed in many psychiatric disorders characterized by emotion dysregulation, including syndromes spanning the internalizing and externalizing spectra, and other conditions such as nonsuicidal self-injury. Nevertheless, some inconsistencies exist. For example, null outcomes in studies of RSA–emotion dysregulation relations are sometimes observed among younger participants. Such findings may derive from use of age inappropriate frequency bands in calculating RSA. We combine data from five published samples (N = 559) spanning ages 4 to 17 years, and reanalyze RSA data using age-appropriate respiratory frequencies. Misspecifying respiratory frequencies results in overestimates of resting RSA and underestimates of RSA reactivity, particularly among young children. Underestimates of developmental shifts in RSA and RSA reactivity from preschool to adolescence were also observed. Although correlational analyses revealed weak negative associations between resting RSA and aggression, those with clinical levels of externalizing exhibited lower resting RSA than their peers. No associations between RSA reactivity and externalizing were observed. Results confirm that age-corrected frequency bands should be used when estimating RSA, and that literature-wide overestimates of resting RSA, underestimates of RSA reactivity, and underestimates of developmental shifts in RSA and RSA reactivity may exist.

Getting to the Heart of Personality in Early Childhood: Cardiac Electrophysiology and Stability of Temperament

Can detection of highly stable individual differences in temperament in early childhood be enhanced using measures of resting heart rate (HR) and respiratory sinus arrhythmia (RSA)? The current longitudinal study (N = 216, 50% female; two to four years old) tested the statistical moderating effects of longitudinal change in resting HR and RSA on stability of mother-rated temperament. Children with the smallest decreases in resting HR and smallest increases in resting RSA had the most stable individual differences in effortful control. In contrast, those with the largest increases in resting RSA had the most stable individual differences in surgency. Including information on HR and RSA can be useful, though the effects depend on the trait and physiological indicator in question.

Toddler parasympathetic regulation and fear: Links to maternal appraisal and behavior

There is a growing recognition that parental socialization influences interact with young children's emerging capacity for physiological regulation and shape children's developmental trajectories. Nevertheless, the transactional processes linking parental socialization and physiological regulatory processes remain not well understood, particularly for fear-prone toddlers. To address this gap in the literature, the present study investigated the biopsychosocial processes that underlie toddlers' fear regulation by examining the relations among toddler parasympathetic regulation, maternal appraisal, and parenting behaviors. Participants included 124 mothers and their toddlers (Mage  = 24.43 months), who participated in a longitudinal study of temperament and socio-emotional development. Toddlers' parasympathetic reactivity was found to moderate the links between maternal anticipatory appraisal of child fearfulness and (a) maternal provision of physical comfort and (b) preschool-age child inhibition. Additionally, maternal comforting behaviors during the low-threat task predicted preschool-age separation distress, specifically for toddlers demonstrating a low baseline RSA.

Shaping emotion regulation: attunement, symptomatology, and stress recovery within mother-infant dyads

The foundations of emotion regulation are organized, in part, through repeated interactions with one's caregiver in infancy. Less is known about how stress physiology covaries between a mother and her infant within these interactions, leaving a gap in our understanding of how the biological basis of emotion regulation develops. This study investigated physiological attunement between mothers and their 5-month-old infants, as well as the influence of maternal depression and anxiety, during stress recovery. During the reengagement phase of the Still Face Paradigm, mother-infant dyads exhibited negative attunement, as measured by inverse covariation of respiratory sinus arrhythmia (RSA). Increases in maternal RSA corresponded to decreases in infant RSA, underscoring dyadic adjustment during recovery. Moreover, infant regulation differed as a function of maternal anxiety, with more anxious mothers having infants with higher RSA during reengagement. Implications for the consolidation of regulatory capabilities within the context of the early caregiving relationship are discussed.

Contributions of Psychophysiology to Research on Adult Attachment: Review and Recommendations

Despite the increasing use of psychophysiological measures to investigate social and interpersonal phenomena, few studies of adult romantic attachment have taken advantage of this approach. In this article I argue for a biologically-specific, theory-based integration of psychophysiological measures into adult attachment research. This approach would help elucidate the normative psychobiological properties of the attachment system, which have received little study in humans. Specifically, it would allow researchers to test targeted hypotheses regarding affect and arousal regulation in attachment relationships. I provide a general introduction to 2 biological systems that hold particular promise for adult attachment research: the parasympathetic branch of the autonomic nervous system and the hypothalamic-pituitary-adrenocortical axis of the endocrine system. I highlight the relevance of these systems for attachment phenomena and review findings from selected social psychophysiological research. I conclude by outlining a tentative theoretical model of the psychobiology of adult attachment and identifying specific directions for future research.

Physiological and Relational Predictors of Mother-Infant Behavioral Coordination

Coordinated social behavior and positive affect shared between parent and child in early life provide a foundation for healthy social and emotional development. We examined physiological (cardiac vagal responses) and relational (attachment security) predictors of dyadic behavioral coordination in a sample of 13-month-old infants and their mothers (N = 64). We tested whether cardiac vagal responses moderated the association between attachment security and behavioral coordination. The main effect of attachment on coordination was moderated by infant cardiac vagal tone (i.e., respiratory sinus arrhythmia [RSA] during rest). Securely attached infants with lower cardiac vagal tone were more behaviorally coordinated with their mothers; there was no association between attachment and coordination for infants with high cardiac vagal tone. Infants with greater increases in cardiac vagal reactivity (i.e., RSA during social engagement) exhibited greater behavioral coordination with their mothers regardless of attachment status. There were no effects for maternal cardiac vagal responses. These results illustrate how individual differences in physiological responses inform healthy early social-emotional functioning.

Vagal tone during infant contingency learning and its disruption

This study used contingency learning to examine changes in infants' vagal tone during learning and its disruption. The heart rate of 160 five-month-old infants was recorded continuously during the first of two training sessions as they experienced an audiovisual event contingent on their pulling. Maternal reports of infant temperament were also collected. Baseline vagal tone, a measure of parasympathetic regulation of the heart, was related to vagal levels during the infants' contingency learning session, but not to their learner status. Vagal tone levels did not vary significantly over session minutes. Instead, vagal tone levels were a function of both individual differences in learner status and infant soothability. Vagal levels of infants who learned in the initial session were similar regardless of their soothability; however, vagal levels of infants who learned in a subsequent session differed as a function of soothability. Additionally, vagal levels during contingency disruption were significantly higher among infants in this group who were more soothable as opposed to those who were less soothable. The results suggest that contingency learning and disruption is associated with stable vagal tone in the majority of infants, but that individual differences in attention processes and state associated with vagal tone may be most readily observed during the disruption phase.

Indirect Effects of Maternal Sensitivity on Infant Emotion Regulation Behaviors: The Role of Vagal Withdrawal

The potential indirect effect of observed maternal sensitivity at 5 months on the development of infants' behavioral regulation of emotion from 5 to 10 months (i.e., distraction and maternal-orientation behaviors) via infant's vagal withdrawal was investigated (N = 230). Results indicated that maternal sensitivity at 5 months was not directly associated with behavioral regulation at 10 months. However, greater maternal sensitivity at 5 months was associated with greater vagal withdrawal at 10 months, after controlling for vagal withdrawal at 5 months. Further, vagal withdrawal at 10 months was associated with greater orientation toward the mother at 10 months, after controlling for 5-month orientation behaviors. The indirect effect of maternal sensitivity on maternal-orientation behaviors was significant, suggesting that infant's vagal withdrawal may be one potential mechanism through which maternal sensitivity is related to behavioral regulation.

Attachment status and mother-preschooler parasympathetic response to the strange situation procedure

BACKGROUND

Early attachment relationships are important for children's development of behavioral and physiological regulation strategies. Parasympathetic nervous system activity, indexed by respiratory sinus arrhythmia (RSA), is a key indicator of self-regulation, with links to numerous developmental outcomes. Attachment-related changes in and associations between mother and child RSA during the Strange Situation procedure (SSP) can elucidate individual differences in physiological response to stress that are important for understanding the development of and intervention for psychopathology.

METHODS

A sample of 142 at-risk mothers and preschool-age children participated in the SSP and provided time-synchronized RSA data during the 7 episodes, which included 2 separations and 2 reunions. Attachment classifications were obtained using the Cassidy et al. (1992) coding system. Linear mixed-effects models were constructed to examine attachment-related change in RSA during the SSP and the concordance between mother and child RSA over time.

RESULTS

Findings demonstrated attachment-related differences in children's RSA. Secure children's RSA was relatively stable over time, whereas insecure-avoidant children showed RSA increases during the first separation and insecure-resistant children's RSA declined across the SSP. Mothers showed RSA withdrawal during separation regardless of child's attachment classification. Mother-child RSA showed a positive concordance that was strongest in the insecure-resistant group, compared with the other groups.

CONCLUSIONS

Results support attachment theories concerning parasympathetic response to stress and the role of the mother-child relationship in physiological regulation. Our findings advance previous research by focusing on at-risk mother-preschooler dyads within diverse attachment classifications.

Does temperament influence language development? Evidence from preterm and full-term children

The aims of this study are: (1) to describe language and temperament characteristics of one group of low risk preterm (PR) children and a group of full-term (FT) children and (2) to identify those factors which can predict language outcomes at 30 months of age, with special attention on temperament. There is evidence of differences between very or extremely PR and FT children in relation to characteristics of temperament and language development. However, not many studies have been carried out with healthy PR children. The participants were 142 low risk PR children (mean gestational age (GA): 32.60 weeks) and 49 FT children (mean GA 39.84 weeks). The temperament of the children was assessed at 10 months of age through the Infant Behavior Questionnaire-Revised (IBQ-R). At 22 months of age the cognitive development of the children was assessed through the Spanish adaptation of the Batelle Developmental Inventory (BDI). In order to assess the children's language development the Galician adaptation of the MacArthur-Bates CDI was applied at 30 months of age. In addition, socio-demographic information about the children and their families was gathered at birth. The results indicate that there were no significant differences in the language measures of interest (word production, MLU3, and sentence complexity) between groups. The only differences found between the PR and the FT children in the IBQ-R were restricted to the smiling and laughter and the fear subscales. Hierarchical regression analyses performed indicate that GA did not have any predictive effect on language measures taken at 30 months. Cognitive scores were an important predictor of language measures, although certain temperament subscales contributed in a significant way to the variance of language measures, particularly low intensity pleasure, approach, high intensity pleasure, sadness, and vocal reactivity. Therefore, extroverted (positive affectivity) temperament seems to be beneficial for language development.

A multilevel prediction of physiological response to challenge: Interactions among child maltreatment, neighborhood crime, endothelial nitric oxide synthase gene (eNOS), and GABA(A) receptor subunit alpha-6 gene (GABRA6)

Physiological response to stress has been linked to a variety of healthy and pathological conditions. The current study conducted a multilevel examination of interactions among environmental toxins (i.e., neighborhood crime and child maltreatment) and specific genetic polymorphisms of the endothelial nitric oxide synthase gene (eNOS) and GABA(A) receptor subunit alpha-6 gene (GABRA6). One hundred eighty-six children were recruited at age 4. The presence or absence of child maltreatment as well as the amount of crime that occurred in their neighborhood during the previous year were determined at that time. At age 9, the children were brought to the lab, where their physiological response to a cognitive challenge (i.e., change in the amplitude of the respiratory sinus arrhythmia) was assessed and DNA samples were collected for subsequent genotyping. The results confirmed that complex Gene × Gene, Environment × Environment, and Gene × Environment interactions were associated with different patterns of respiratory sinus arrhythmia reactivity. The implications for future research and evidence-based intervention are discussed.

Behavioral and facial thermal variations in 3-to 4-month-old infants during the Still-Face Paradigm

Behavioral and facial thermal responses were recorded in twelve 3- to 4-month-old infants during the Still-Face Paradigm (SFP). As in the usual procedure, infants were observed in a three-step, face-to-face interaction: a normal interaction episode (3 min); the “still-face” episode in which the mother became unresponsive and assumed a neutral expression (1 min); a reunion episode in which the mother resumed the interaction (3 min). A fourth step that consisted of a toy play episode (5 min) was added for our own research interest. We coded the behavioral responses through the Infant and Caregiver Engagement Phases system, and recorded facial skin temperature via thermal infrared (IR) imaging. Comparing still-face episode to play episode, the infants’ communicative engagement decreased, their engagement with the environment increased, and no differences emerged in self-regulatory and protest behaviors. We also found that facial skin temperature increased. For the behavioral results, infants recognized the interruption of the interactional reciprocity caused by the still-face presentation, without showing upset behaviors. According to autonomic results, the parasympathetic system was more active than the sympathetic, as usually happens in aroused but not distressed situations. With respect to the debate about the causal factor of the still-face effect, thermal data were consistent with behavioral data in showing this effect as related to the infants’ expectations of the nature of the social interactions being violated. Moreover, as these are associated to the infants’ subsequent interest in the environment, they indicate the thermal IR imaging as a reliable technique for the detection of physiological variations not only in the emotional system, as indicated by research to date, but also in the attention system. Using this technique for the first time during the SFP allowed us to record autonomic data in a more ecological manner than in previous studies.

Mutual influences between child emotion regulation and parent–child reciprocity support development across the first 10 years of life: Implications for developmental psychopathology

Elucidating the mechanisms by which infant birth conditions shape development across lengthy periods is critical for understanding typical and pathological development and for targeted early interventions. This study examined how newborns' regulatory capacities impact 10-year outcomes via the bidirectional influences of child emotion regulation (ER) and reciprocal parenting across early development. Guided by dynamic systems theory, 125 infants were tested at seven time points: birth, 3, 6, 12, and 24 months and 5 and 10 years. Initial regulatory conditions were measured by respiratory sinus arrhythmia (RSA; vagal tone) and neurobehavioral regulation (Brazelton, 1973) at birth. At each assessment between 3 months and 5 years, infant ER was microcoded from age-appropriate paradigms and mother–child reciprocity observed during social interactions. Four regulation-related outcomes were measured at 10 years: child RSA, empathy measured by mother–child conflict discussion and a lab paradigm, accident proneness, and behavior problems. An autoregressive cross-lagged structural model indicated that infant birth conditions impacted 10-year outcomes via three mechanisms. First, child ER and reciprocal parenting were individually stable across development and were each predicted by regulatory birth conditions, describing gradual maturation of ER and reciprocity over time. Second, better ER skills at one time point were related to greater reciprocity at the next time point and vice versa, and these cross-time effects defined a field of individual-context mutual influences that mediated the links between neonatal RSA and 10-year outcomes. Third, direct associations emerged between neonatal regulation and outcome, suggesting that birth conditions may establish a neurobiological milieu that promotes a more mature and resilient system. These mechanisms describe distinct “attractor” states that constrain the system's future options, emphasize the importance of defining behavior-based phenotypes of heterotypic continuity, and suggest that infants may shape their development by initiating unique cascades of individual-context bidirectional effects.

Heart rate variability as a transdiagnostic biomarker of psychopathology

The Research Domain Criteria (RDoC), developed by the National Institute of Mental Health as a neuroscience-informed alternative to traditional psychiatric nosology, is an explicitly dimensional system in which classification of psychopathology is derived inductively (i.e., from basic science), across multiple levels of analysis (e.g., genetic, neural, psychophysiological, and behavioral). Although RDoC is often presented as paradigmatically revolutionary, a review of the history of psychophysiology suggests that roots of RDoC thinking extend at least as far back as the mid-20th Century. In this paper, we briefly and selectively review the historical emergence of neurobiologically-informed dimensional trait models of psychopathology, and we summarize our thinking regarding high frequency heart rate variability (HF-HRV) as a transdiagnostic biomarker of self-regulation and cognitive control. When functional interactions between HF-HRV and systems of behavioral approach and avoidance are considered, diverse patterns of behavioral maladjustment can be subsumed into a single model. This model accommodates the general bifactor structure of psychopathology, and suggests that HF-HRV can be viewed as an autonomic, transdiagnostic biomarker of mental illness.

Roots and Benefits of Costly Giving: Children Who Are More Altruistic Have Greater Autonomic Flexibility and Less Family Wealth

Altruism, although costly, may promote well-being for people who give. Costly giving by adults has received considerable attention, but less is known about the possible benefits, as well as biological and environmental correlates, of altruism in early childhood. In the current study, we present evidence that children who forgo self-gain to help other people show greater vagal flexibility and higher subsequent vagal tone than children who do not, and children from less wealthy families behave more altruistically than those from wealthier families. These results suggest that (a) altruism should be viewed through a biopsychosocial lens, (b) the influence of privileged contexts on children's willingness to make personal sacrifices for others emerges early, and (c) altruism and healthy vagal functioning may share reciprocal relations in childhood. When children help others at a cost to themselves, they could be playing an active role in promoting their own well-being as well as the well-being of others.