A transactional analysis of the relation between maternal sensitivity and child vagal regulation

Exploring predictors of interaction among low-birth-weight infants and their caregivers: a machine learning-based random forest approach

BACKGROUND

Quality caregiver-infant interaction is crucial for infant growth, health, and development. Traditional methods for evaluating the quality of caregiver-infant interaction have predominantly relied on rating scales or observational techniques. However, rating scales are prone to inaccuracies, while observational techniques are resource-intensive. The utilization of easily collected medical records in conjunction with machine learning techniques offers a promising and viable strategy for accurate and efficient assessment of caregiver-infant interaction quality.

METHODS

This study was conducted at a follow-up outpatient clinic at two tertiary maternal and infant health centers located in Shanghai, China. 68 caregivers and their 3-15-month-old infants were videotaped for 3-5 min during playing interactions in non-threatening environment. Two trained experts utilized the Infant CARE-Index (ICI) procedure to assess whether the caregivers were sensitive or not in a dyadic context. This served as the gold standard. Predictors were collected through Health Information Systems (HIS) and questionnaires, which included accessible features such as demographic information, parental coping ability, infant neuropsychological development, maternal depression, parent-infant interaction, and infant temperament. Four classification models with fivefold cross-validation and grid search hyperparameter tuning techniques were employed to yield prediction metrics. Interpretable analyses were conducted to explain the results.

RESULTS

The score of sensitive caregiver-infant interaction was 6.34 ± 2.62. The Random Forest model gave the best accuracy (83.85%±6.93%). Convergent findings identified infant age, care skills of infants, mother age, infant temperament-regulatory capacity, birth weight, positive coping, health-care-knowledge-of-infants, type of caregiver, MABIS-bonding issues, ASQ-Fine Motor as the strongest predictors of interaction sensitivity between infants and their caregiver.

CONCLUSIONS

The proposed method presents a promising and efficient approach that synergistically combines rating scales and artificial technology to detect important features of caregiver-infant interactions. This novel approach holds several implications for the development of automatic computational assessment tools in the field of nursing studies.

Humanity's evolved nest and its relation to cardiac vagal regulation in the first years of life

BACKGROUND

The Evolved Developmental Niche (EDN) is a millions-year-old developmental system that matches the maturational schedule of the offspring, optimizing health. Every animal has a developmental niche.

AIMS

Humanity has fallen away from providing its EDN. Does it matter?

STUDY DESIGN

Several components of humanity's EDN were reviewed (breastfeeding, positive touch, allomothers, responsive care, free play) in relation to cardiac vagal nerve regulation, a signal of healthy development. Focal subjects were young children.

OUTCOME MEASURES

A review of research on the selected EDN components in relation to vagal nerve function was performed. Data were available for all but the allomother component, which is typically not measured by western researchers, although allomothers provide EDN components alongside parents.

RESULTS

Apart from the lack of research on allomother effects, all these EDN components have been shown to influence cardiac vagal regulation in young children.

CONCLUSIONS

Converging evidence suggests that providing the EDN in early life may not only support aspects of a child's primal health system, but bolster capacities for social health and wellness, the cornerstone of a positive life trajectory.

Using Attachment and Biobehavioral Catch-up with young children with developmental delays: A multiple-baseline trial of attachment, sensitivity, and cortisol

The Attachment and Biobehavioral Catchup intervention potentially offsets psychosocial risks facing dyads in which children have intellectual disability or developmental delays. In this single-case multiple-baseline study the efficacy of this intervention was tested across three such South African families. Maternal sensitivity, attachment security, and child affect regulation were measured weekly during a baseline and intervention period, using the Ainsworth Maternal Sensitivity Scales, Attachment Q-sort and salivary cortisol, respectively. Furthermore, post-intervention interviews invited parents' and intervenors' evaluations of the intervention. Visual analysis broadly indicated improvement in maternal sensitivity and attachment security across subjects over time following the introduction of the intervention, although randomisation tests were not statistically significant. Effects on affect regulation were not clearly observed and may have been influenced by case-specific variables. Parent-participants and intervenors also identified particularly helpful contributions from the intervention. Findings underscore the importance of individual-level effects evaluation, especially when implementing interventions outside the original population.

Parental sensitivity modifies the associations between maternal prenatal stress exposure, autonomic nervous system functioning and infant temperament in a diverse, low-income sample

Evidence suggests that adversity experienced during fetal development may shape infant physiologic functioning and temperament. Parental sensitivity is associated with child stress regulation and may act as a buffer against risk for intergenerational health effects of pre- or postnatal adversity. Building upon prior evidence in a racially and ethnically diverse sample of infants (M infant age = 6.5 months) and women of low socioeconomic status, this study examined whether coded parenting sensitivity moderated the association between an objective measure of prenatal stress exposures (Stressful Life Events (SLE)) and infant parasympathetic (respiratory sinus arrhythmia; RSA) or sympathetic (pre-ejection period; PEP) nervous system functioning assessed during administration of the Still-Face-Paradigm (SFP) (n = 66), as well as maternal report of temperament (n = 154). Results showed that parental sensitivity moderated the associations between prenatal stress exposures and infant RSA reactivity, RSA recovery, PEP recovery, and temperamental negativity. Findings indicate that greater parental sensitivity is associated with lower infant autonomic nervous system reactivity and greater recovery from challenge. Results support the hypothesis that parental sensitivity buffers infants from the risk of prenatal stress exposure associations with offspring cross-system physiologic reactivity and regulation, potentially shaping trajectories of health and development and promoting resilience.

Transactional associations between infant negative emotionality and maternal sensitivity: Maternal emotion dysregulation as a moderator

The relations between maternal sensitivity and infant negative emotionality have been tested extensively in the previous literature. However, the extent to which these associations reflect unidirectional or bidirectional effects over time remains somewhat uncertain. Further, the possibility that maternal characteristics moderate the extent to which infant negative emotionality predicts maternal sensitivity over time has yet to be tested in cross-lag models. The goal of the present study is to address these gaps. First time mothers (N = 259; 50% White; 50% Black) and their infants participated when infants were 6, 14, and 26 months of age. Infant negative emotionality was assessed via maternal report and direct observation during standardized laboratory tasks, which were subsequently combined to yield a multimethod measure at each wave. Maternal sensitivity was observationally coded at each wave and mothers self-reported emotion dysregulation at 6 and 14 months. A random intercepts cross-lagged model with maternal emotion dysregulation specified as a moderator revealed that infant negative emotionality at 6 months was negatively associated with maternal sensitivity at 14 months, but only among mothers higher in emotion dysregulation. Higher maternal sensitivity was in turn associated with lower infant negative emotionality when infants were 26 months of age. The indirect pathway was significant, lending support for the transactional model. Implications for future research and prevention/intervention are discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A systematic review and meta-analysis of the association between parenting and child autonomic nervous system activity

Parental socialization may influence the development of children's autonomic nervous system (ANS), a key stress-response system. However, to date no quantitative synthesis of the literature linking parenting and child ANS physiology has been conducted. To address this gap, we conducted a pre-registered meta-analysis. A systematic review of the literature identified 103 studies (n = 13,044 participants) with available effect sizes describing the association between parenting and either parasympathetic nervous system (PNS) or sympathetic nervous system (SNS) activity in children. The overall analysis revealed non-significant associations between parenting and child ANS physiology on average. However, moderation analyses revealed a positive association between more positive parenting and higher resting PNS activity that was stronger when a study was experimental rather than correlational, and when the sample included children with a clinical condition. In conclusion, well-controlled experimental studies show that positive parenting is associated with the development of higher resting PNS activity, an effect that may be stronger among children who are at elevated developmental risk.

Maternal Sensitivity Modulates Child's Parasympathetic Mode and Buffers Sympathetic Activity in a Free Play Situation

Background

Behavioral and physiological (self-)regulation in early life is crucial for the understanding of childhood development and adjustment. The autonomic nervous system (ANS) is a main player in the regulative system and should therefore be modulated by the quality of interactive behavior of the caregiver. We experimentally investigated the ANS response of 18–36-month-old children in response to the quality of maternal behavior during a mother–child-interacting paradigm.

Method

Eighty mothers and their children came to our laboratory and took part in an experimental paradigm, consisting of three episodes: a resting phase (E1), a structured play phase (E2), and a free play situation (E3) between mothers and their child. Children’s and mother’s heart rate (HR), the sympathetic nervous system (SNS) activity via the pre-ejection period (PEP) and the left ventricular ejection time (LVET), and the parasympathetic nervous system (PNS) activity via the respiratory sinus arrhythmia (RSA) were continuously measured by an electrocardiogram. Maternal sensitivity of interactive behavior was assessed by using the Emotional Availability (EA) Scales.

Results

Children of mothers with insensitive behavior had a significantly lower RSA at baseline, showed a lack of RSA withdrawal during structured and free play, and had shorter LVET across all episodes compared to children of sensitive mothers.

Conclusion

Our findings depict the influence of low-quality maternal interaction on the child’s ANS regulation, in calm and more stressful play situations. The overall higher SNS mode with impaired PNS reactivity may negatively influence child’s ANS homoeostasis, which may result in a long-term impact on mental and physical wellbeing. Further, the maternal sensitivity may function as a buffer for the stress response of their child. These results could serve as a basis for the development of appropriate psychoeducational programs for mothers of low sensitivity in their interaction with the child.

Parents' Maltreatment Histories, Dimensions of Emotion Regulation, and Connections to Offspring Self-Regulation: A Sex-Specific Transmission Pathway

Introduction

Parents with childhood maltreatment histories are at risk for emotion regulation (ER) problems, which are associated with reduced self-regulation among their offspring. However, gaps remain in the literature regarding this indirect transmission pathway. First, ER consists of multiple dimensions and it is unclear which dimension is most affected by childhood maltreatment. Second, less is known regarding which parental ER dimension is linked to offspring self-regulation. Thus, the present study aimed to examine the direct and indirect associations between parental maltreatment histories and child self-regulatory capacity via dimensions of parental ER.

Methods

In this cross-sectional study, 101 youth (75% African American/Black; 53% female; M _age = 10.28; SD = 1.19) and their primary caregivers were recruited from a low-income community in the Southeastern United States. Structural equation modeling was used to model the effect of parents' self-reported childhood maltreatment on youth physiological self-regulation (measured by heart rate variability reactivity [HRV-R]), via parents' self-reported ER.

Results

Parental maltreatment history was significantly associated with five of the six components of ER. Further, the indirect effect of parents' childhood maltreatment on child HRV-R was significant when parents reported more difficulty engaging goal-directed behaviors. Moderation analyses by sex showed that daughters had greater dysregulation regardless of parental maltreatment histories, while parents' ER was found to play a more significant role in the intergenerational transmission of dysregulation to sons.

Conclusions

The current study extends the literature on self-regulation development in children of low-income, maltreatment-exposed parents. Our study may inform parent-child interventions for improving self-regulation.

Within- and between-family transactions of maternal depression and child engagement in the first 2 years of life: Role of prenatal maternal risk and tobacco use

BACKGROUND

This study examined transactional associations among maternal depression, maternal sensitivity, and child engagement in the context of a low-income, diverse sample with maternal cigarette smoking during pregnancy (MSDP) as a moderator of these transactions.

METHODS

A random-intercept cross-lagged panel model was used to investigate within- and between-family variability from infancy to toddlerhood. The sample included 247 mother-child dyads (47% girls; 51% African-American; 178 MSDP, 69 non-MSDP). Assessments were conducted once during each trimester of pregnancy and at 2, 9, 16, and 24 months of child ages.

RESULTS

Between-family associations revealed that children exposed to higher levels of sensitive parenting across time had higher behavioral engagement from infancy to toddlerhood. At the within-family level, increased sensitive parenting at 9 months was predictive of increased child engagement at 16 months which in turn predicted increases in sensitive parenting at 24 months. Increased maternal depression was concurrently associated with lower maternal sensitivity at 2 months and lower child engagement at 16 months. Contrary to hypotheses, changes in maternal depression were not associated to changes in parenting or child engagement. These associations did not vary between prenatally smoking and nonsmoking mothers. However, there was significantly higher stability in maternal depression across time among nonsmoking mothers compared to those in the MSDP group. Additionally, increased maternal depression was related to lower-than-expected child engagement at 9 months only for the nonsmoking group.

CONCLUSIONS

Results highlight transactional processes at the within-family level and the importance of timing for parent and child effects on transactional processes.

Effects of adverse childhood experience on physiological regulation are moderated by evolved developmental niche history

Childhood experiences of early life stress and adversity can lead to long-term detrimental outcomes across the lifespan. Recent evidence suggests avoiding stressors is not enough for species-typical development. Nurturing and responsive care are needed to both buffer adverse experiences as well as promote healthy development, but little is known regarding the interaction between species-typical environmental support in childhood, Evolved Developmental Niche history (EDN-history), and adversity on physiological regulation in adult women. To investigate the interaction between species-typical nurturing and adversity (ACEs, adverse childhood experiences), women (N = 113) were asked to report on EDN-history and ACEs. Physiological regulation was measured using respiratory sinus arrhythmia (RSA) across three conditions that included stress and relaxation. Applying latent basis coefficient modeling, EDN-history moderated vagal withdrawal from baseline to stress and supported vagal activation from stress to recovery, suggesting a link between EDN-history and vagal adaptability. EDN-history acted as a buffer against ACEs on physiological regulation supporting women's vagal adaptability across differing conditions. Physiological adaptability is a key component of physical and psychological wellbeing and resilience. Experiences of the EDN in childhood may not only buffer adversity but also support the physiological building blocks of health and resilience.

Second-by-second infant and mother emotion regulation and coregulation processes

Context-appropriate infant physiological functioning may support emotion regulation and mother-infant emotion coregulation. Among a sample of 210 low-income Mexican-origin mothers and their 24-week-old infants, dynamic structural equation modeling (DSEM) was used to examine whether within-infant vagal functioning accounted for between-dyad differences in within-dyad second-by-second emotion regulation and coregulation during free play. Vagal functioning was captured by within-infant mean and variability (standard deviation) of respiratory sinus arrhythmia (RSA) during free play. Infant emotion regulation was quantified as emotional equilibria (within-person mean), volatility (within-person deviation from equilibrium), carryover (how quickly equilibrium is restored following a disturbance), and feedback loops (the extent to which prior affect dampens or amplifies subsequent affect) in positive and negative affect during free play; coregulation was quantified as the influence of one partner's affect on the other's subsequent affect. Among infants with lower RSA variability, positive affect fluctuated around a higher equilibrium, and negative affect fluctuated around a lower equilibrium; these infants exhibited feedback loops where their positive affect dampened their subsequent negative affect. As expected, infants with higher mean RSA exhibited more volatility in positive affect, feedback loops between their positive and negative affect, and stronger mother-driven emotion coregulation. The results highlight differences in simultaneously occurring biological and emotion regulation.

Supporting families to protect child health: Parenting quality and household needs during the COVID-19 pandemic

BACKGROUND

Supportive parenting is critical for promoting healthy child development in the face of stressors, such as those occurring during COVID-19. Here, we address a knowledge gap regarding specific household risk factors associated with parenting quality during the pandemic and incorporate first-person accounts of family challenges and needs.

METHODS

Mixed methods were applied to data collected between April 14th - 28th, 2020 from the "Parenting During the Pandemic" survey. Participants included 656 primary caregivers (e.g., mothers, fathers, foster parents) of least one child age 1.5-8 years of which 555 (84.6%) responded to at least one parenting questionnaire. Parenting quality was assessed across stressful, negative, and positive parenting dimensions. Household risk was examined across pandemic- linked (e.g., caregiver depression, unmet childcare needs) and stable factors (i.e., annual income, mental illness history). Significant correlates were examined with regressions in Mplus. Thematic analysis identified caregiver challenges and unmet needs from open-ended questions.

FINDINGS

Caregiver depression, higher child parity, unmet childcare needs, and relationship distress predicted lower-quality parenting. Caregiver depression was the most significant predictor across every parenting dimension, with analyses indicating medium effect sizes, ds = .39 - .73. Qualitative findings highlighted severe strains on parent capacities including managing psychological distress, limited social supports, and too much unstructured time.

INTERPRETATIONS

Lower quality parenting during COVID-19 is associated with multiple household and pandemic risk factors, with caregiver depression consistently linked to parent- child relationship disruptions. Focused efforts are needed to address caregiver mental health to protect child health as part of the pandemic response.

Supporting families to protect child health: Parenting quality and household needs during the COVID-19 pandemic

Background

Supportive parenting is critical for promoting healthy child development in the face of stressors, such as those occurring during COVID-19. Here, we address a knowledge gap regarding specific household risk factors associated with parenting quality during the pandemic and incorporate first-person accounts of family challenges and needs.

Methods

Mixed methods were applied to data collected between April 14th - 28th, 2020 from the “Parenting During the Pandemic” survey. Participants included 656 primary caregivers (e.g., mothers, fathers, foster parents) of least one child age 1.5–8 years of which 555 (84.6%) responded to at least one parenting questionnaire. Parenting quality was assessed across stressful, negative, and positive parenting dimensions. Household risk was examined across pandemic- linked (e.g., caregiver depression, unmet childcare needs) and stable factors (i.e., annual income, mental illness history). Significant correlates were examined with regressions in Mplus. Thematic analysis identified caregiver challenges and unmet needs from open-ended questions.

Findings

Caregiver depression, higher child parity, unmet childcare needs, and relationship distress predicted lower-quality parenting. Caregiver depression was the most significant predictor across every parenting dimension, with analyses indicating medium effect sizes, ds = .39 - .73. Qualitative findings highlighted severe strains on parent capacities including managing psychological distress, limited social supports, and too much unstructured time.

Interpretations

Lower quality parenting during COVID-19 is associated with multiple household and pandemic risk factors, with caregiver depression consistently linked to parent- child relationship disruptions. Focused efforts are needed to address caregiver mental health to protect child health as part of the pandemic response.

Parental Socialization of Emotion and Psychophysiological Arousal Patterns in Children with Autism Spectrum Disorder

Children with autism spectrum disorder (ASD) are at considerable risk for difficulties with emotion regulation and related functioning. Although it is commonly accepted that parents contribute to adaptive child regulation, as indexed by observable child behavior, theory and recent evidence suggest that parenting may also influence relevant underlying child physiological tendencies. The current study examined concurrent associations between two elements of parental socialization of emotion and measures of both sympathetic and parasympathetic nervous system activity in 61 children with ASD aged 6 to 10 years. To index parental socialization, parents reported on their reactions to their children's negative emotions, and parental scaffolding was coded from a dyadic problem-solving task. Children's baseline respiratory sinus arrhythmia (RSA), electrodermal reactivity (EDA-R), and RSA reactivity in response to challenge were obtained as measures of the children's physiological activity. Regression analyses indicated that supportive parent reactions were related to higher child baseline RSA, a biomarker of regulatory capacity. Fewer unsupportive parent reactions and higher quality scaffolding were associated with higher EDA-R, a physiological index of inhibition. The identification of these concurrent associations represents a first step in understanding the complex and likely bidirectional interplay between parent socialization and child physiological reactivity and regulation in this high-risk population.

Appetite self-regulation declines across childhood while general self-regulation improves: A narrative review of the origins and development of appetite self-regulation

This narrative review discusses the origins and development of appetite self-regulation (ASR) in childhood (from infancy to age 6 or 7 years). The origins, or foundations, are the biological infrastructure associated with appetite regulation and appetite self-regulation. Homeostatic regulation in infancy is examined and then evidence about developmental change in components of ASR. The main ASR-related components covered are: delay-of-gratification, caloric compensation, eating in the absence of hunger, food responsiveness/hedonics and fussy eating. The research included behavioral measures, parent-reports of appetitive traits and fMRI studies. There were two main trends in the evidence: a decline across childhood in the components of ASR associated with food approach (and therefore an increase in disinhibited eating), and wide individual differences. The decline in ASR contrasts with general self-regulation (GSR) where the evidence is of an improvement across childhood. For many children, bottom-up automatic reactive processes via food reward/hedonics or food avoidance as in fussy eating, appear not to be matched by improvements in top-down regulatory capacities. The prominence of bottom-up processes in ASR could be the main factor in possible differences in developmental paths for GSR and ASR. GSR research is situated in developmental science with its focus on developmental processes, theory and methodology. In contrast, the development of ASR at present does not have a strong developmental tradition to access and there is no unifying model of ASR and its development. We concluded (1) outside of mean-level or normative changes in the components of ASR, individual differences are prominent, and (2) there is a need to formulate models of developmental change in ASR together with appropriate measurement, research designs and data analysis strategies.

Factors associated with parenting self-efficacy: A systematic review

Aims

To provide an overview of the parental, child, and socio‐contextual factors related to general parenting self‐efficacy (PSE) in the general population.

Design

Systematic review.

Data sources

Medline Ovid, Web of Science, Embase, and PsycINFO Ovid were systematically searched for studies published between January 1980‐June 2020.

Review Methods

Studies were included if they described associations between factor(s) and PSE among parents of children aged 0–18 years old in the general population, and published in an English language peer‐reviewed journal. Studies with participants from specific populations, studies describing the development of instruments for PSE, qualitative studies, reviews, theses, conference papers and book chapters were excluded. Belsky's process model of parenting guided the data synthesis.

Results

Of 3,819 articles, 30 articles met the inclusion criteria. Eighty‐nine factors were identified. There was evidence of associations between child temperament, maternal parenting satisfaction, parenting stress, maternal depression, household income, perceived social support and PSE. Evidence was inconsistent for an association of educational level, parity, number of children in the household and PSE in mothers. There was no evidence of an association for child gender, age, marital status and PSE in both mothers and fathers; ethnicity, age, employment status in mothers; household income in fathers; and educational level, parenting fatigue in parents.

Conclusion

A range of factors studied in relation to PSE was identified in this systematic review. However, the majority of the factors was reported by one or two studies often implementing a cross‐sectional design.

Impact

There is some evidence for an association between some potentially modifiable factors and PSE in the general population, this information may be used by health and social professionals supporting child health and well‐being. Future longitudinal studies are recommended to study parental, child and socio‐contextual factors associated with PSE to inform the development of intervention strategies.

Latent profiles of children's autonomic nervous system reactivity early in life predict later externalizing problems

Prior researchers have observed relations between children's autonomic nervous system reactivity and externalizing behavior problems, but rarely considers the role of developmentally regulated changes in children's stress response systems. Using growth mixture modeling, the present study derived profiles of parasympathetic nervous system reactivity (as indicated by respiratory sinus arrhythmia (RSA)) and sympathetic nervous system reactivity (as indicated by pre-ejection period (PEP)) from low income, primarily Mexican American children measured repeatedly from infancy through age 5 (N = 383) and investigated whether profiles were associated with externalizing problems at age 7. Analyses identified two profiles of RSA reactivity (reactive decreasing and U-shaped reactivity) and three profiles of PEP reactivity (blunted/anticipatory reactivity, reactive decreasing, non-reactive increasing). Compared to children with an RSA profile of reactive decreasing, those with an RSA profile of U-shaped reactivity had marginally higher externalizing problems, however, this difference was not statistically significant. Children who demonstrated a profile of blunted/anticipatory PEP reactivity had significantly higher externalizing problems compared to those with a profile of non-reactive increasing, likely related to the predominantly male composition of the former profile and predominantly female composition of the latter profile. Findings contribute to our understanding of developmental trajectories of ANS reactivity and highlight the utility of a longitudinal framework for understanding the effects of physiological risk factors on later behavior problems.

Linking preschoolers' parasympathetic activity to maternal early adversity and child behavior: An intergenerational perspective

Increasing evidence suggests intergenerational effects of maternal early adversity on offspring self-regulation. Prior work has demonstrated associations between maternal adverse childhood experiences (ACEs) and infant respiratory sinus arrhythmia (RSA), a parasympathetic biomarker associated with emotional and behavioral self-regulation. The present study examined these associations and additional potential pathways including children's violence exposure and maternal psychopathology among 123 biological mother-child dyads. Families were low-income and oversampled for violence exposure; children were 3-5 years old. RSA was examined during dyadic interaction using latent growth curve modeling (LGCM). On average, females exhibited greater RSA reactivity. Greater RSA withdrawal across the interaction was associated with greater child negative affect during the interaction, linking RSA reactivity to concurrent child behavior. Consistent with previous findings among infants, high maternal ACEs were associated with lower child RSA at task initiation but not with RSA reactivity across the interaction. Findings suggest that the association between high maternal ACEs and a lower set point for offspring RSA persists into the early childhood period, beyond the influence of maternal psychopathology and children's own violence exposure. These data provide further evidence for the biological embedding of maternal early adversity across generations as well as for the relevance of RSA to child behavioral regulation.

Maternal socialization of child emotion and adolescent adjustment: Indirect effects through emotion regulation

A fundamental question in developmental science is how parental emotion socialization processes are associated with children's subsequent adaptation. Few extant studies have examined this question across multiple developmental periods and levels of analysis. Here, we tested whether mothers' supportive and nonsupportive reactions to their 5-year-old children's negative emotions were associated with teacher and adolescent self-reported adjustment at age 15 via children's physiological and behavioral emotion regulation at age 10 (N = 404). Results showed that maternal supportive reactions to their children's negative emotions were associated with children's greater emotion regulation in a laboratory task and also a composite of mother and teacher reports of emotion regulation at age 10. Maternal nonsupportive reactions to their children's negative emotions were uncorrelated with supportive reactions, but were associated with poorer child physiological regulation and also poorer mother- and teacher-reported emotion regulation at age 10. In turn, better physiological regulation at age 10 was associated with more adolescent-reported social competence at age 15. Furthermore, teacher and mother reports of emotion regulation at age 10 were associated with increased adolescent adjustment across all domains. Mediational effects from nonsupportive and supportive reactions to adolescent adjustment tested via bootstrapping were significant. Our findings suggest that mothers' reactions to their children's negative emotions in early childhood may play a role in their children's ability to regulate their arousal both physiologically and behaviorally in middle childhood, which in turn may play a role in their ability to manage their emotions and behaviors and to navigate increasingly complex social contexts in adolescence. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Reduced caregiving quality measured during the strange situation procedure increases child's autonomic nervous system stress response

BACKGROUND

Dysfunctional maternal behavior has been shown to lead to disturbances in infant's regulatory capacities and alterations in vagal reactivity. We aim to investigate the autonomic nervous system (ANS) response of the child during the strange situation procedure (SSP) in relation to the quality of maternal behavior.

METHODS

Twelve month after birth, 163 mother-child-dyads were investigated during the SSP. Heart rate (HR) and both, the parasympathetic branch (PNS) via the respiratory sinus arrhythmia (RSA) and the sympathetic branch (SNS) via the left ventricular ejection time (LVET) of the ANS were continuously determined during the SSP using electrocardiogram (ECG) and impedance cardiogram (ICG) measures. Maternal behavior was assessed by using the AMBIANCE measure.

RESULTS

The ANS response in infants of mothers with disruptive behavior compared to infants of non-disruptive mothers was significantly altered during the SSP: HR increased especially when infants of disruptive mothers were alone with the stranger (F (1, 161) = 4.15, p = .04) with a significant vagal withdrawal when being in contact with the stranger despite of presence of the mother (F (1, 161) = 5.11, p = .03) and a significant increase in vagal tone during final reunion (F (1, 161) = 3.76, p = .05). HR increase was mainly based on a decrease in LVET (F (1, 161) = 4.08, p = .05) with a maximum infant's HR when the stranger came into the room instead of the mother.

CONCLUSION

Both, SNS and PNS branches of the child are significantly altered in terms of an ANS imbalance, especially during contract to a stranger, in relation to dysfunctional maternal behavior. Our findings suggest the importance of supporting high quality caregiving that enables the infant to adapt adequately to stressful interpersonal situations which is likely to promote later health.

Does early maternal responsiveness buffer prenatal tobacco exposure effects on young children's behavioral disinhibition?

Children with prenatal tobacco exposure (PTE) exhibit early self-regulatory impairments, reflecting a life-course persistent propensity toward behavioral disinhibition. Previously, we demonstrated the protective role of parental responsiveness for reducing the risk of exposure-related disruptive behavior in adolescence. Here, we expanded this line of inquiry, examining whether responsiveness moderates the relation of PTE to a broader set of behavioral disinhibition features in early childhood and testing alternative diathesis-stress versus differential susceptibility explanatory models. PTE was assessed prospectively using interviews and bioassays in the Midwestern Infant Development Study (MIDS). Mother-child dyads (N = 276) were re-assessed at approximately 5 years of age in a preschool follow-up. We quantified maternal responsiveness and child behavioral disinhibition using a combination of directly observed activities in the lab and developmentally sensitive questionnaires. Results supported a diathesis-stress pattern. Children with PTE and less responsive mothers showed increased disruptive behavior and lower effortful control compared with children without PTE. In contrast, exposed children with more responsive mothers had self-regulatory profiles similar to their non-exposed peers. We did not observe sex differences. Findings provide greater specification of the protective role of maternal responsiveness for self-regulation in children with PTE and help clarify mechanisms that may underscore trajectories of exposure-related behavioral disinhibition.

Temperamental vulnerability to emotion dysregulation and risk for mental and physical health challenges

Emotion dysregulation characterizes many forms of psychopathology. Patterns of dysregulation occur as a function of a developmental process in which normative and adaptive emotion regulation skills fail to become part of the child's behavioral repertoire due to biological, psychological, and contextual processes and experiences. Here we highlight the processes involved in the dysregulation of temperamental anger and frustration that become core features of externalizing problems and place children at risk for more serious forms of psychopathology. We imbed these processes in a larger self-regulatory framework, and we discuss how they influence mental as well as physical health, using data from our 20-year longitudinal study following a large cohort of children into young adulthood. Recommendations are made for future research involving the integration of biological systems with mental and physical health outcomes.

A biopsychosocial approach to processes and pathways in the development of overweight and obesity in childhood: Insights from developmental theory and research

Childhood obesity has reached alarming proportions in many countries. There is consensus that both biological (especially genetic) and environmental (including psychosocial) factors contribute to weight gain and obesity in childhood. Research has identified extensive risk or predictive factors for childhood obesity from both of these domains. There is less consensus about the developmental processes or pathways showing how these risk factors lead to overweigh/obesity (OW/OB) in childhood. We outline a biopsychosocial process model of the development of OW/OB in childhood. The model and associated scholarship from developmental theory and research guide an analysis of research on OW/OB in childhood. The model incorporates biological factors such as genetic predispositions or susceptibility genes, temperament, and homeostatic and allostatic processes with the psychosocial and behavioral factors of parenting, parental feeding practices, child appetitive traits, food liking, food intakes, and energy expenditure. There is an emphasis on bidirectional and transactional processes linking child biology and behavior with psychosocial processes and environment. Insights from developmental theory and research include implications for conceptualization, measurement, research design, and possible multiple pathways to OW/OB. Understanding the developmental processes and pathways involved in childhood OW/OB should contribute to more targeted prevention and intervention strategies in childhood.

Infant frontal EEG asymmetry moderates the association between maternal behavior and toddler negative affectivity

Relatively little work has examined potential interactions between child intrinsic factors and extrinsic environmental factors in the development of negative affect in early life. This work is important because high levels of early negative affectivity have been associated with difficulties in later childhood adjustment. We examined associations between infant frontal electroencephalogram (EEG), maternal parenting behaviors, and children's negative affect across the first two years of life. Infant baseline frontal EEG asymmetry was measured at 5 months; maternal sensitivity and intrusiveness were observed during mother-child interaction at 5 and 24 months; and mothers provided reports of toddler negative affect at 24 months. Results indicated that maternal sensitive behaviors at 5 months were associated with less negative affect at 24 months, but only for infants with left frontal EEG asymmetry. Similarly, maternal sensitive behaviors at 24 months were associated with less toddler negative affect at 24 months, but only for infants with left frontal EEG asymmetry. In contrast, maternal intrusive behaviors at 5- and 24-months were associated with greater toddler negative affect, but only for infants with right frontal EEG asymmetry at 5-months. Findings suggest that levels of negative affect in toddlers may be at least partially a result of interactions between children's own early neurophysiological functioning and maternal behavior during everyday interactions with children in the first two years of life.

Traumatic stress and the autonomic brain-gut connection in development: Polyvagal Theory as an integrative framework for psychosocial and gastrointestinal pathology

A range of psychiatric disorders such as anxiety, depression, and post-traumatic stress disorder frequently co-occur with functional gastrointestinal (GI) disorders. Risk of these pathologies is particularly high in those with a history of trauma, abuse, and chronic stress. These scientific findings and rising awareness within the healthcare profession give rise to a need for an integrative framework to understand the developmental mechanisms that give rise to these observations. In this paper, we introduce a plausible explanatory framework, based on the Polyvagal Theory (Porges, Psychophysiology, 32, 301-318, 1995; Porges, International Journal of Psychophysiology, 42, 123-146, 2001; Porges, Biological Psychology, 74, 116-143, 2007), which describes how evolution impacted the structure and function of the autonomic nervous system (ANS). The Polyvagal Theory provides organizing principles for understanding the development of adaptive diversity in homeostatic, threat-response, and psychosocial functions that contribute to pathology. Using these principles, we outline possible mechanisms that promote and maintain socioemotional and GI dysfunction and review their implications for therapeutic targets.

An intervention that increases parental sensitivity in families referred to Child Protective Services also changes toddlers' parasympathetic regulation

Experiencing maltreatment in early childhood predicts poor parasympathetic regulation, characterized by low baseline parasympathetic activity and strong withdrawal of parasympathetic influence in response to tasks. The Promoting First Relationships® (PFR) program improves parental sensitivity toward young children in families identified as maltreating. Using a subsample from a randomized control trial, we examined whether parental participation in PFR had lasting effects on toddlers' parasympathetic regulation, as measured by respiratory sinus arrhythmia (RSA), relative to a resource and referral control condition. In addition, we examined whether parental sensitive and responsive behavior mediated or moderated associations between parent treatment group and children's RSA. More than 6 months after completing treatment, 29 families in the PFR condition and 30 families in the control condition were visited at home, and toddlers' RSA was assessed at baseline and during five moderately challenging tasks. Groups did not differ in baseline RSA, but differed in RSA reactivity to the tasks. Across tasks, toddlers of parents in the control condition manifested significantly larger RSA decreases than toddlers of parents in the PFR condition. Parental behavior showed divergent associations with RSA change for toddlers of parents in the PFR versus control condition, with PFR treatment predicting RSA change ranging from small decreases to increases in toddlers of parents who showed the most sensitive, responsive behavior in the 6 months following treatment. This preliminary study showed that the same intervention that improved parenting also improved toddlers' parasympathetic regulation in response to everyday activities, warranting further experimental investigation.

Maternal emotional support but not cognitive support during problem-solving predicts increases in cognitive flexibility in early childhood

Cognitive flexibility is a sophisticated form of executive functions that predicts a range of adaptive outcomes; however, little is known about which caregiving behaviors predict the rapid improvements in children’s cognitive flexibility during early childhood. This study examined whether ordinary variations in mothers’ provision of emotional and cognitive support during problem-solving predict children’s cognitive flexibility and tested whether children’s cognitive flexibility predicts caregiving behaviors across time. Two hundred and seventy-eight children and their caregivers (96% mothers) participated in laboratory visits when children were in preschool, kindergarten, and first grade. At each visit, cognitive flexibility was measured via a computerized version of the Dimensional Change Card Sort task and mothers’ behaviors were observed during a semi-structured problem-solving board game task. Results from autoregressive cross-lagged structural regression analyses indicated that mothers’ emotional support predicted greater child cognitive flexibility from preschool to kindergarten, and from kindergarten to first grade, after accounting for the stability in these constructs over time and controlling for the influence of maternal education, and child age and minority status. Mothers’ cognitive support did not predict child cognitive flexibility over time. Child cognitive flexibility did not lead to changes in caregiving behaviors over time. Findings suggest that mothers’ provision of emotional support during problem-solving may be an important proximal mechanism that contributes to children’s cognitive flexibility across early childhood.

Developmental Cascade and Transactional Associations Among Biological and Behavioral Indicators of Temperament and Maternal Behavior

An empirical model of temperament that assessed transactional and cascade associations between respiratory sinus arrhythmia (RSA), negative affectivity, and the caregiving environment (i.e., maternal intrusiveness) across three time points during infancy (N = 388) was examined. Negative affectivity at 5 months was associated positively with maternal intrusiveness at 10 months, which in turn predicted increased negative affectivity at 24 months. RSA at 5 months was associated positively with negative affectivity at 10 months, which subsequently predicted greater RSA at 24 months. Finally, greater RSA at 5 months predicted greater negative affectivity at 10 months, which in turn predicted greater maternal intrusiveness at 24 months. Results are discussed from a biopsychosocial perspective of development.

Contributions of mothers' and fathers' parenting to children's self-regulation: Evidence from an adoption study

The origins of top-down self-regulation are attributed to genetic and socialization factors as evidenced by high heritability estimates from twin studies and the influential role of parenting. However, recent evidence suggests that parenting behavior itself is affected by parents' own top-down self-regulation. Because children's top-down self-regulation is influenced by genetic factors and parenting is influenced by top-down self-regulation, the effects of parenting on children's top-down self-regulation identified in prior studies may partially reflect passive gene-environment correlation. The goal of this study was to examine parenting influences on children's top-down self-regulation using a longitudinal, adoption-at-birth design, a method of identifying parenting influences that are independent of the role of shared genetic influences on children's characteristics because adoptive parents are genetically unrelated to their adopted child. Participants (N = 361) included adoptive families and biological mothers of adopted children. Adoptive mothers' and fathers' harsh/negative parenting were assessed when children were 27 months of age and biological mothers' top-down self-regulation was assessed when children were 54 months of age. Adopted children's top-down self-regulation was assessed when they were 54 and 72 months of age. Results, accounting for child gender, biological mother top-down self-regulation, and the potential evocative effects of adopted child anger, provide evidence that inherited influences and socialization processes uniquely contribute to children's top-down self-regulation. Furthermore, findings demonstrate the importance of both mother's and father's parenting behavior as an influence on young children's top-down self-regulation. The implications of these findings for understanding the complex mechanisms that influence children's top-down self-regulation are discussed.

Vagal Regulation of Cardiac Function in Early Childhood and Cardiovascular Risk in Adolescence

OBJECTIVE

Poor behavioral self-regulation in the first 2 decades of life has been identified as an important precursor of disease risk in adulthood. However, physiological regulation has not been well studied as a disease risk factor before adulthood. We tested whether physiological regulation at the age of 2 years, in the form of vagal regulation of cardiac function (indexed by respiratory sinus arrhythmia [RSA] change), would predict three indicators of cardiovascular risk at the age of 16 years (diastolic and systolic blood pressure and body mass index).

METHODS

Data came from 229 children who participated in a community-based longitudinal study. At the age of 2 years, children were assessed for RSA baseline and RSA change (ln(ms)) in response to a series of challenge tasks. These same children were assessed again at the age of 16 years for diastolic and systolic blood pressure (millimeters of mercury), height (meters), and weight (kilogram).

RESULTS

Regression analyses revealed that less RSA withdrawal at the age of 2 years predicted higher diastolic blood pressure at the age of 16 years, adjusting for demographic characteristics (B = -3.07, M [S E] = 1.12, p = .006). Follow-up analyses demonstrated that these predictions extended to clinically significant levels of diastolic prehypertension (odds ratio = 0.43, 95% confidence interval = 0.22-0.89). RSA withdrawal did not significantly predict adolescent body mass index or systolic blood pressure.

CONCLUSIONS

Vagal regulation of cardiac function in early childhood predicts select indicators of cardiovascular risk 14 years later. Early signs of attenuated vagal regulation could indicate an increased risk for elevated blood pressure before adulthood. Future research should test biological, behavioral, and psychological mechanisms underlying these long-term predictions.

Child cortisol moderates the association between family routines and emotion regulation in low-income children

Biological and social influences both shape emotion regulation. In 380 low-income children, we tested whether biological stress profile (cortisol) moderated the association among positive and negative home environment factors (routines; chaos) and emotion regulation (negative lability; positive regulation). Children (M age = 50.6, SD = 6.4 months) provided saliva samples to assess diurnal cortisol parameters across 3 days. Parents reported on home environment and child emotion regulation. Structural equation modeling was used to test whether cortisol parameters moderated associations between home environment and child emotion regulation. Results showed that home chaos was negatively associated with emotion regulation outcomes; cortisol did not moderate the association. Child cortisol level moderated the routines-emotion regulation association such that lack of routine was most strongly associated with poor emotion regulation among children with lower cortisol output. Findings suggest that underlying child stress biology may shape response to environmental influences.

Maternal abuse history and reduced fetal heart rate variability: Abuse-related sleep disturbance is a mediator

The consequences of childhood maltreatment are profound and long lasting. Not only does the victim of abuse suffer as a child, but there is mounting evidence that a history of maltreatment places the next generation at risk for significant psychopathology. Research identifies postnatal factors as affecting this intergenerational transmission of trauma. However, emerging evidence suggests that part of this risk may be transmitted before birth, passed on via abuse-related alterations in the in utero environment that are as yet largely unidentified. To date, no study has directly assessed the influence of pregnant women's abuse history on fetal neurobehavioral development, nor considered trauma-associated poor sleep quality as a mediator reflecting established physiological dysregulation. Using data from 262 pregnant adolescents (ages 14-19), a population at elevated risk for childhood maltreatment, the current study examined maternal emotional abuse history and sleep quality in relation to third-trimester fetal resting heart rate variability, an index of parasympathetic nervous system functioning. The results indicate that maternal emotional abuse history is indirectly associated with lower fetal heart rate variability via abuse-related sleep disturbances. These data demonstrate an association between maternal abuse histories and fetal development, showing that at least part of the intergenerational transmission of risk occurs during pregnancy.

Childhood adversity and epigenetic regulation of glucocorticoid signaling genes: Associations in children and adults

Early childhood experiences have lasting effects on development, including the risk for psychiatric disorders. Research examining the biologic underpinnings of these associations has revealed the impact of childhood maltreatment on the physiologic stress response and activity of the hypothalamus-pituitary-adrenal axis. A growing body of literature supports the hypothesis that environmental exposures mediate their biological effects via epigenetic mechanisms. Methylation, which is thought to be the most stable form of epigenetic change, is a likely mechanism by which early life exposures have lasting effects. We present recent evidence related to epigenetic regulation of genes involved in hypothalamus-pituitary-adrenal axis regulation, namely, the glucocorticoid receptor gene (nuclear receptor subfamily 3, group C, member 1 [NR3C1]) and FK506 binding protein 51 gene (FKBP5), after childhood adversity and associations with risk for psychiatric disorders. Implications for the development of interventions and future research are discussed.

Genetic moderation of transactional relations between parenting practices and child self-regulation

The present study addressed the ways in which parent and child dopamine D4 receptor (DRD4) genotypes jointly moderate the transactional relations between parenting practices and child self-regulation. African American children (N = 309) and their parents provided longitudinal data spanning child ages 11 to 15 years and a saliva sample from which variation at DRD4 was genotyped. Based on the differential susceptibility perspective, this study examined moderation effects of DRD4 status on (a) the extent to which parenting practices affect child self-regulation and (b) the extent to which child self-regulation, as an environmental influence on the parent, affects parenting behavior. Results indicated that responsive-supportive parenting interacted with children's DRD4 status to influence increases in child self-regulation. Also, child self-regulation interacted with parent's DRD4 status to predict changes in parenting practices. Both Gene × Environment effects conformed to a differential susceptibility model in which parents' and children's DRD4 genes operated to increase environmental sensitivity "for better and for worse." (PsycINFO Database Record

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.

Multigenerational links between mothers' experiences of autonomy in childhood and preschoolers' respiratory sinus arrhythmia: Variations by maltreatment status

Despite burgeoning evidence linking early exposure to child maltreatment (CM) to deficits in self-regulation, the pathways to strong regulatory development in these children are not well understood, and significant heterogeneity is observed in their outcomes. Experiences of autonomy may play a key role in transmitting self-regulatory capacity across generations and help explain individual differences in maltreatment outcomes. In this study, we investigated multigenerational associations between Generation 1 (G1)-Generation 2 (G2) mothers' early experience of warmth and autonomy in relation to their own mothers and their Generation 3 (G3) children's autonomic physiological regulation in CM (n = 85) and non-CM (n = 128) families. We found that G2 mothers who recalled greater autonomy in their childhood relationship with their G1 mothers had preschool-age G3 children with higher respiratory sinus arrhythmia at baseline when alone while engaged in individual challenge tasks, during social exchanges with their mother in joint challenge tasks, and during the portions of the strange situation procedure when the mother was present. Although no clear mediators of this association emerged, multigenerational links among G1-G2 relations, maternal representations of her child, child behavior, and child respiratory sinus arrhythmia differed by maltreatment status, thus possibly representing important targets for future research and intervention.

Regulating sadness and fear from outside and within: mothers' emotion socialization and adolescents' parasympathetic regulation predict the development of internalizing difficulties

Multilevel models of developmental psychopathology implicate both characteristics of the individual and their rearing environment in the etiology of internalizing problems and disorders. Maladaptive regulation of fear and sadness, the core of anxiety and depression, arises from the conjoint influences of ineffective parasympathetic regulation of emotion and ineffective emotion socialization experiences. In 171 youths (84 female, M = 13.69 years, SD = 1.84), we measured changes of respiratory sinus arrhythmia (RSA) in response to sadness- and fear-inducing film clips and maternal supportive and punitive responses to youths' internalizing emotions. Youths and mothers reported on youths' internalizing problems and anxiety and depression symptoms concurrently and 2 years later at Time 2. Maternal supportive emotion socialization predicted fewer, and punitive socialization predicted more, mother-reported internalizing problems at Time 2 only for youths who showed RSA suppression to fear-inducing films. More RSA suppression to sadness-inducing films predicted more youth-reported internalizing problems at Time 2 in girls only. In addition, less supportive emotion socialization predicted more youth-reported depression symptoms at Time 2 only for girls who showed more RSA suppression to sadness. RSA suppression to sadness versus fear might reflect different patterns of atypical parasympathetic regulation of emotional arousal, both of which increase the risk for internalizing difficulties in youths, and especially girls, who lack maternal support for regulating emotions.

Intergenerational transmission of self-regulation: A multidisciplinary review and integrative conceptual framework

This review examines mechanisms contributing to the intergenerational transmission of self-regulation. To provide an integrated account of how self-regulation is transmitted across generations, we draw from over 75 years of accumulated evidence, spanning case studies to experimental approaches, in literatures covering developmental, social, and clinical psychology, and criminology, physiology, genetics, and human and animal neuroscience (among others). First, we present a taxonomy of what self-regulation is and then examine how it develops--overviews that guide the main foci of the review. Next, studies supporting an association between parent and child self-regulation are reviewed. Subsequently, literature that considers potential social mechanisms of transmission, specifically parenting behavior, interparental (i.e., marital) relationship behaviors, and broader rearing influences (e.g., household chaos) is considered. Finally, evidence that prenatal programming may be the starting point of the intergenerational transmission of self-regulation is covered, along with key findings from the behavioral and molecular genetics literatures. To integrate these literatures, we introduce the self-regulation intergenerational transmission model, a framework that brings together prenatal, social/contextual, and neurobiological mechanisms (spanning endocrine, neural, and genetic levels, including gene-environment interplay and epigenetic processes) to explain the intergenerational transmission of self-regulation. This model also incorporates potential transactional processes between generations (e.g., children's self-regulation and parent-child interaction dynamics that may affect parents' self-regulation) that further influence intergenerational processes. In pointing the way forward, we note key future directions and ways to address limitations in existing work throughout the review and in closing. We also conclude by noting several implications for intervention work.

Respiratory sinus arrhythmia, effortful control, and parenting as predictors of children's sympathy across early childhood

The goal of this study was to examine physiological and environmental predictors of children's sympathy (an emotional response consisting of feelings of concern or sorrow for others who are distressed or in need) and whether temperamental effortful control mediated these relations. Specifically, in a study of 192 children (23% Hispanic; 54% male), respiratory sinus arrhythmia (RSA), a measure thought to reflect physiological regulation, and observed authoritative parenting (both at 42 months) were examined as predictors of children's effortful control (at 54 months) and, in turn, children's sympathy (at 72 and 84 months). Measures of both baseline RSA and RSA suppression were examined. In a structural equation model, observed parenting was positively related to children's subsequent sympathy through its positive relation to effortful control. Furthermore, the indirect path from baseline RSA to higher sympathy through effortful control was marginally significant. Authoritative parenting and baseline RSA uniquely predicted individual differences in children's effortful control. Findings highlight the potential role of both authoritative parenting and physiological regulation in the development of children's sympathy.