A path model examination: maternal anxiety and parenting mediate the association between maternal adverse childhood experiences and children's internalizing behaviors.

BACKGROUND: Children of mothers with adverse childhood experiences (ACEs) are at increased risk for developmental problems. However, the mechanisms through which a mother's experience of ACEs are transmitted to her offspring are understudied. The current study investigates potential modifiable mediators (maternal psychopathology and parenting) of the association between maternal ACEs and children's behavioral problems. METHODS: We utilized data from a pregnancy cohort study (N = 1030; CANDLE study) to investigate longitudinal associations between maternal ACEs, postpartum anxiety, observed parenting behavior, and child internalizing behaviors (meanage = 4.31 years, s.d. age = 0.38) in a racially diverse (67% Black; 33% White/Other) sample. We used structural equation modeling to test for direct associations between maternal ACEs and children's internalizing behaviors, as well as indirect associations via two simple mediations (maternal anxiety and parenting), and one serial mediation (sequence of maternal anxiety to parenting). RESULTS: Simple mediation results indicated that maternal anxiety and cognitive growth fostering behaviors independently mediated the association between maternal ACEs and child internalizing. We observed no evidence of a serial mediation from ACEs to internalizing via the effects of maternal anxiety on parenting. CONCLUSIONS: This study supports and refines extant literature by confirming the intergenerational association between maternal ACEs and child internalizing behaviors in a large, diverse sample, and identifies potential modifiable mediators: maternal anxiety and parenting behaviors related to fostering cognitive development. Findings may inform interventions targeting mothers who have experienced ACEs and suggest that providing support around specific parenting behaviors and addressing maternal anxiety may reduce internalizing behaviors in children.

Endorsement of a single-item measure of sleep disturbance during pregnancy and risk for postpartum depression: a retrospective cohort study.

Poor prenatal sleep quality is associated with increased risk for depressive symptoms but may go undetected in brief, busy prenatal care visits. Among non-depressed pregnant participants, we evaluated whether 1) the endorsement of sleep disturbance on a depression questionnaire predicted postpartum depressive symptoms, 2) the strength of these associations was higher than other somatic symptoms of pregnancy and depression (i.e., fatigue, appetite disturbance), and 3) the endorsement of prenatal sleep disturbance varied by participant characteristics. In this retrospective cohort study, participants had a live birth and completed Patient Health Questionnaire (PHQ-9) during pregnancy and within 8 weeks postpartum between 2012 and 2017. Participants who were non-depressed during pregnancy (PHQ-9 < 10) were included (n = 3619). We operationalized sleep disturbance, fatigue, and appetite disturbance as endorsement of item 3, 4, and 5 on the PHQ-9, respectively, and postpartum depressive symptoms as PHQ-9 total score ≥ 10. Participant characteristic variables included age, race, ethnicity, parity, gestational age at delivery, and preterm birth. Prenatal sleep disturbance was associated with higher odds of postpartum depressive symptoms (aORs 1.9, 95% CI 1.2-3.1 for first trimester; 3.7, 95% CI 1.5-11.5 for second trimester; 3.4, 95% CI 1.9-6.8 for third trimester). Fatigue and appetite disturbance in the first and third trimesters were associated with higher odds of postpartum depressive symptoms. Sleep disturbance varied by race during the first and second trimesters (p < 0.05) and was highest among Black or African American participants (61.8-65.1%). A routinely administered single-item measure of sleep disturbance could identify otherwise lower-risk pregnant individuals who may benefit from depression prevention efforts.

Is it me or my child? The association between maternal depression and children's behavior problems in mothers and their children with or without autism.

Bidirectional associations between maternal depression and child behavior problems have been reported in prior research, however, few studies examine these relations across varied family contexts. This study examined parenting stress and child diagnosis of autism spectrum disorder (ASD) as moderators of bidirectional associations between maternal depression and child behavior problems over time. Our sample included 86 mother-child dyads who reported maternal depressive symptoms, child behavior problems, and parenting stress at three time points over more than 1 year. Approximately half were mothers of children with ASD (n = 41) and half were mothers of neurotypical children (n = 45). We tested the bidirectional associations between maternal depressive symptoms and children's behavior problems and the potential moderating role of parental stress or child ASD diagnosis on these bidirectional associations using aggregated, lagged, and linear mixed models. Even after controlling for lagged maternal depressive symptoms, child behavior problems were associated with greater subsequent maternal depression at the between-person level, but not at the within-person level. The converse relation of prior maternal depressive symptoms on subsequent child behavior problems was not significant. Neither parenting stress nor child ASD diagnosis moderated bidirectional associations between maternal depressive symptoms and children's behavior problems. Child behavior predicted maternal depression, but the converse was not true, regardless of parenting stress levels or child's ASD diagnosis. For mothers experiencing elevated parenting stress and those with children with ASD, this may help alleviate elevated feelings of guilt related to their children's behavior problems.

Trajectories of depressive symptoms among mothers of preterm and full-term infants in a national sample.

To examine postpartum depressive symptom trajectories from birth to age 5 and their risk factors in a national sample of mothers of preterm and full-term infants. The racially and ethnically diverse sample comprised 11,320 maternal participants (Mage = 29; SD = 5.9) in the Environmental influences on Child Health Outcomes (ECHO) Program in the USA with data on newborn gestational age at birth (≥ 22 weeks) and maternal depression symptoms during the first 5 years following childbirth. Growth mixture models determined the number and trajectory of postpartum depression classes among women in the preterm and full-term groups, and we examined predictors of class membership. Five trajectories described depressive symptoms for both groups; however, notable differences were observed. One in 5 mothers of preterm infants developed clinically relevant depressive symptoms over time compared with 1 in 10 mothers of full-term infants. Among women who delivered preterm compared with those who delivered full-term, symptoms were more likely to increase over time and become severe when offspring were older. Distinct subgroups describe mothers' depressive symptom trajectories through 5 years following childbirth. Mild to moderate depressive symptoms may onset or persist for many women beyond the initial postpartum period regardless of newborn gestational age at birth. For women with preterm infants, initially mild symptoms may increase to high levels of severity during the preschool and toddler years.

Maternal Depressive Symptoms, Paternal Engagement, and Toddler Behavior Problems in Low-income Mexican-origin Families.

OBJECTIVE: Maternal postpartum depression (PPD) may influence fathers' engagement in childrearing; however, empirical studies have been equivocal as to whether these effects emerge in a compensatory (i.e., higher paternal engagement) or spillover (i.e., lower paternal engagement) manner. This study evaluated fathers' gender role attitudes as a moderator that shapes the association between maternal PPD and fathers' engagement during infancy, and also examined relations between father engagement and children's subsequent behavior problems. METHOD: In a prospective study of low-income, Mexican-origin families (N = 181 mothers and a subset of their partners, N = 92 fathers), maternal PPD symptoms and fathers' gender role attitudes were measured at 15-weeks postpartum, father engagement was measured at 21-weeks, and children's behavior problems were measured at 12 and 18 months. RESULTS: Higher maternal PPD symptoms were associated with lower father engagement and more child behavior problems when fathers endorsed more segregated gender role attitudes; however, this relation was not significant when fathers endorsed less segregated, more contemporary gender role attitudes. A mediational chain was evident, wherein the interaction of maternal PPD and fathers' gender role attitudes predicted paternal engagement, and lower paternal engagement subsequently predicted more child behavior problems at 12 months, which predicted more child behavior problems at 18 months. CONCLUSIONS: Results suggest the effects of maternal PPD on children's behavior problems may operate via paternal engagement, which is affected by fathers' traditional gender role attitudes. The study highlights the importance of examining fathering and children's behavior using a cultural-contextual lens among underrepresented ethnic minority families.

Transactions between Maternal and Child Depressive Symptoms Emerge Early in Life.

Maternal depression is a robust risk factor for children's internalizing symptoms; however, the intergenerational transmission of mood disorders is likely more complex than unidirectional parent-directed effects. Theoretical models support transactional associations between maternal and child symptomatology over time but have not been well examined, especially in younger high-risk samples. The present investigation examined predictive transactional relations between maternal depression and children's internalizing in toddlerhood and early childhood using a cross-lagged panel model. Participants were 162 low-income, largely racial/ethnic minority mothers and their offspring (32% African American, 16% White, 52% Other/Multiethnic; 53% female) who were assessed when children were 18 months and 4 years old. There were significant cross-sectional relations between maternal depressive and child internalizing symptoms when children were 18 months but not 4 years of age. Cross-lagged associations were evident such that maternal depression symptoms at 18 months were positively associated with internalizing symptoms among children at 4 years, adjusting for prior maternal symptom levels and the cross-sectional correlations between maternal-child symptoms at 18 months. Within the same model, children's internalizing symptoms at 18 months were also positively associated with maternal depressive symptoms at 4 years, adjusting for prior child symptom levels and cross-sectional correlations. This study is among the first to demonstrate that transactional relations between maternal and child mood symptoms occur as early as toddlerhood/early childhood. Findings highlight the potential utility of inclusive, family-focused interventions that support both parents and children in the treatment of early emotional problems.

Evidence for discrete profiles of children's physiological activity across three neurobiological system and their transitions over time.

The conceptualization of stress-responsive physiological systems as operating in an integrated manner is evident in several theoretical models of cross-system functioning. However, limited empirical research has modeled the complexity of multisystem activity. Moreover few studies have explored developmentally regulated changes in multisystem activity during early childhood when plasticity is particularly pronounced. The current study used latent profile analysis (LPA) to evaluate multisystem activity during fall and spring of children's transition to kindergarten in three biological systems: the parasympathetic nervous system (PNS), sympathetic nervous system (SNS), and hypothalamic pituitary adrenal (HPA) axis. Latent transition analysis (LTA) was then used to examine the stability of profile classification across time. Across both timepoints, three distinct profiles of multisystem activity emerged. One profile was characterized by heightened HPA axis activity (HPA Axis Responders), a second profile was characterized by moderate, typically adaptive patterns across the PNS, SNS, and HPA axis (Active Copers/Mobilizers), and a third profile was characterized by heightened baseline activity, particularly in the PNS and SNS (Anticipatory Arousal/ANS Responders). LTA of fall-to-spring profile classifications indicated higher probabilities that children remained in the same profile over time compared to probabilities of profile changes, suggesting stability in certain patterns of cross-system responsivity. Patterns of profile stability and change were associated with socioemotional outcomes at the end of the school year. Findings highlight the utility of LPA and LTA to detect meaningful patterns of complex multisystem physiological activity across three systems and their associations with early adjustment during an important developmental transition.

Developmental Consequences of Early Life Stress on Risk for Psychopathology: Longitudinal Associations with Children's Multisystem Physiological Regulation and Executive Functioning.

The etiology of psychopathology is multifaceted and warrants consideration of factors at multiple levels and across developmental time. Although experiences of adversity in early life have been associated with increased risk of developing psychopathology, pathways toward maladaptation or resilience are complex and depend upon a variety of factors, including individuals' physiological regulation and cognitive functioning. Therefore, in a longitudinal cohort of 113 mother-child dyads, we explored associations from early adverse experiences to physiological co-regulation across multiple systems and subsequent variations in executive functioning. Latent profile analysis derived multisystem profiles based on children's heart rate, respiratory sinus arrhythmia, pre-ejection period, and cortisol measured during periods of rest and reactivity throughout a developmentally challenging protocol. Three distinct profiles of multisystem regulation emerged: heightened multisystem baseline activity (Anticipatory Arousal/ANS Responder), typically adaptive patterns across all systems (Active Copers/Mobilizers) and heightened HPA axis activity (HPA Axis Responders). Path models revealed that children exposed to adversity before 18-months were more likely to evidence an Anticipatory Arousal/ANS Responders response at 36-months, and children in this profile had lower executive functioning scores than the Active Copers/Mobilizers. In sum, these findings provide important information about potential physiological associations linking early adversity to variations in children's task-based executive functioning.

Infant biological sensitivity to father engagement in low-income Mexican American families.

Despite a sizeable literature documenting meaningful contributions of father involvement to child health and development, researchers have paid little attention to biological characteristics that may render a child more or less sensitive to fathering behavior. The identification of child and paternal characteristics that promote child behavioral health is particularly critical in the context of sociocultural risk. We hypothesized that respiratory sinus arrhythmia (RSA) measured during infancy would moderate the impact of father engagement in caregiving activities on child behavioral health. In a sample of 181 Mexican American families, we evaluated the impact of infant RSA at 6 weeks, mother- and father-reported father engagement in caregiving activities at 15 and 21 weeks, and their interaction on toddler social or emotional behavior problems and competence at 2 years of age. Only infants with average or higher RSA exhibited more behavior problems in the context of low father engagement (p = .021). Neither RSA nor father engagement predicted behavioral competence. The results are consistent with a stress-diathesis process such that higher infant RSA increases vulnerability to suboptimal father involvement, but does not enhance the benefits of high father involvement.

Effects of maternal and paternal postnatal depressive symptoms on infants' parasympathetic regulation in low-income, Mexican American families.

Mothers and fathers are at elevated risk for developing depression during the first postnatal year, especially among families from marginalized communities. Although a number of studies demonstrate that exposure to maternal depressive symptoms can undermine infants' regulatory development, less is known about the extent to which paternal depressive symptoms may also contribute. The current study investigated whether maternal and paternal depressive symptoms were uniquely associated with infants' physiological regulation, and whether associations varied depending on infant sex. Participants included 90 low-income Mexican American families. Fathers and mothers self-reported their depressive symptoms when infants were 15 weeks old, and infants' resting parasympathetic activity (i.e., respiratory sinus arrhythmia [RSA]) was assessed at 6 and 24 weeks. Results indicated that, after controlling for infant 6-week RSA and depressive symptoms in the other parent, paternal depressive symptoms were associated with lower 24-week RSA for both girls and boys, but maternal depressive symptoms were only associated with lower 24-week RSA for boys. Findings highlight a potential mechanism through which the consequences of parent depressive symptoms may reverberate across generations, and suggest that considerations of both infants' and parents' sex may lend insight into how best to intervene.

Associations between multisystem stress reactivity and peer nominated aggression in early childhood vary by sex.

There is emerging evidence that the development of problematic aggression in childhood may be associated with specific physiological stress response patterns, with both biological overactivation and underactivation implicated. This study tested associations between sex-specific patterns of stress responses across the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis and peer nominations of aggression among 271 kindergarten children (Mean age = 5.32 years; 52% Female; 44% White). Upon entry to kindergarten, children participated in a multidomain standardized stress paradigm. Changes in pre-ejection period (PEP) and salivary cortisol were assessed. On a separate day, children provided peer ratings of physical and relational aggression in a standardized interview. As expected, there was a significant three-way interaction between PEP, cortisol reactivity, and sex, but only for physical aggression. Among boys, cortisol reactivity was positively associated with physical aggression only for those with higher SNS reactivity. Findings suggest that for boys, asymmetrical and symmetrical HPA/SNS reactivity may be associated with lower and higher risk for peer-directed physical aggression, respectively. Understanding the complex associations between multisystem physiology, child sex and peer-directed aggression in early childhood may offer insight into individual differences underlying the emergence of behavioral dysregulation in early peer contexts.

Informant-specific reports of peer and teacher relationships buffer the effects of harsh parenting on children's oppositional defiant disorder during kindergarten.

Harsh and restrictive parenting are well-established contributors to the development of oppositional defiant disorder (ODD) among children. However, few studies have explored whether interpersonal relationships that develop outside the family environment attenuate the risk for ODD that is associated with harsh parenting. The current study tested multireporter measures of teacher-child closeness and peer acceptance as moderators of the association between harsh parenting and children's ODD as children's social worlds widen during the kindergarten year (N = 338 children, 48% girls, M age = 5.32 years). Harsh parenting interacted with peer nominations of peer acceptance and children's report of teacher-child closeness to predict children's ODD symptoms in the spring, adjusting for fall symptoms. Children exposed to harsh parenting exhibited greater symptom increases when they were less liked/accepted playmates and in the context of lower teacher-child closeness. However, harsh parenting was not associated with symptom change among children with higher levels of peer-nominated acceptance and those who reported closer relationships with teachers. There were no significant interactions using teacher's report of peer acceptance or teacher's report of teacher-child closeness. Findings highlight positive peer and teacher relationships as promising targets of intervention among children exposed to harsh parenting and support the importance of assessing multiple perspectives of children's social functioning.

Associations between classroom climate and children's externalizing symptoms: The moderating effect of kindergarten children's parasympathetic reactivity.

Classrooms are key social settings that impact children's mental health, though individual differences in physiological reactivity may render children more or less susceptible to classroom environments. In a diverse sample of children from 19 kindergarten classrooms (N = 338, 48% female, M age = 5.32 years), we examined whether children's parasympathetic reactivity moderated the association between classroom climate and externalizing symptoms. Independent observers coded teachers' use of child-centered and teacher-directed instructional practices across classroom social and management domains. Children's respiratory sinus arrhythmia reactivity to challenge tasks was assessed in fall and a multi-informant measure of externalizing was collected in fall and spring. Both the social and the management domains of classroom climate significantly interacted with children's respiratory sinus arrhythmia reactivity to predict spring externalizing symptoms, controlling for fall symptoms. For more reactive children, as classrooms shifted toward greater proportional use of child-centered methods, externalizing symptoms declined, whereas greater use of teacher-dominated practices was associated with increased symptoms. Conversely, among less reactive children, exposure to more teacher-dominated classroom management practices was associated with lower externalizing. Consistent with the theory of biological sensitivity to context, considering variability in children's physiological reactivity aids understanding of the salience of the classroom environment for children's mental health.

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.

Children's biobehavioral reactivity to challenge predicts DNA methylation in adolescence and emerging adulthood.

A growing body of research has documented associations between adverse childhood environments and DNA methylation, highlighting epigenetic processes as potential mechanisms through which early external contexts influence health across the life course. The present study tested a complementary hypothesis: indicators of children's early internal, biological, and behavioral responses to stressful challenges may also be linked to stable patterns of DNA methylation later in life. Children's autonomic nervous system reactivity, temperament, and mental health symptoms were prospectively assessed from infancy through early childhood, and principal components analysis (PCA) was applied to derive composites of biological and behavioral reactivity. Buccal epithelial cells were collected from participants at 15 and 18 years of age. Findings revealed an association between early life biobehavioral inhibition/disinhibition and DNA methylation across many genes. Notably, reactive, inhibited children were found to have decreased DNA methylation of the DLX5 and IGF2 genes at both time points, as compared to non-reactive, disinhibited children. Results of the present study are provisional but suggest that the gene's profile of DNA methylation may constitute a biomarker of normative or potentially pathological differences in reactivity. Overall, findings provide a foundation for future research to explore relations among epigenetic processes and differences in both individual-level biobehavioral risk and qualities of the early, external childhood environment.

Family Socioeconomic Status, Cortisol, and Physical Health in Early Childhood: The Role of Advantageous Neighborhood Characteristics.

OBJECTIVE: Children from families with lower socioeconomic status (SES) evidence greater physiological dysregulation and poorer health. Despite recognition of environmental contributors, little is known about the influence of neighborhood characteristics. The present study examined the moderating role of community-level risks and resources on the relation of family SES to children's daily cortisol output and physical health during the kindergarten year. METHODS: In fall and spring of kindergarten, children's (N = 338) daily total cortisol was measured and parents and teachers rated children's global physical health. Parents reported family SES. Neighborhood characteristics were assessed using the Child Opportunity Index, a population-level tool that evaluates the quality of multiple domains of neighborhood attributes. RESULTS: In fall, children reared in lower SES family environments had higher cortisol when residing in lower quality (lower opportunity) neighborhoods (b = -.097, p < .001), but there was no relation between family SES and children's cortisol in more advantaged (higher opportunity) neighborhoods (b = -.023, p = .36). Lower family SES was prospectively associated with poorer physical health in spring (controlling for fall health) only among children living in lower opportunity neighborhoods (b = -.250, p = .018) and was unrelated to physical health among children residing in higher opportunity neighborhoods (b = .042, p = .70). CONCLUSIONS: Higher opportunity neighborhoods may protect against the negative consequences of low family SES on children's stress physiology and physical health. Public health interventions that bolster neighborhood opportunities may benefit young children reared in socioeconomically disadvantaged family environments.

Effect of prenatal mindfulness training on depressive symptom severity through 18-months postpartum: A latent profile analysis.

OBJECTIVE: We examined whether prenatal mindfulness training was associated with lower depressive symptoms through 18-months postpartum compared to treatment as usual (TAU). METHOD: A controlled, quasi-experimental trial compared prenatal mindfulness training (MMT) to TAU. We collected depressive symptom data at post-intervention, 6-, and 18-months postpartum. Latent profile analysis identified depressive symptom profiles, and multinomial logistic regression examined whether treatment condition predicted profile. RESULTS: Three depressive symptom severity profiles emerged: none/minimal, mild, and moderate. Adjusting for relevant covariates, MMT participants were less likely than TAU participants to be in the moderate profile than the none/minimal profile (OR = 0.13, 95% CI = 0.03-0.54, p = .005). CONCLUSIONS: Prenatal mindfulness training may have benefits for depressive symptoms during the transition to parenthood.

Child temperament and teacher relationship interactively predict cortisol expression: The prism of classroom climate.

Entry into kindergarten is a developmental milestone that children may differentially experience as stressful, with implications for variability in neurobiological functioning. Guided by the goodness-of-fit framework, this study tested the hypothesis that kindergarten children's (N = 338) daily cortisol would be affected by the "match" or "mismatch" between children's temperament and qualities of the classroom relational context. The robustness of these associations was also explored among a separate sample of children in third grade (N = 165). Results among kindergarten children showed negative affectivity and overcontrolled temperament were positively related to cortisol expression within classrooms characterized by lower levels of teacher motivational support, but there was no relation between temperament and cortisol when motivational support was higher. Among third-grade children, negative affectivity was marginally positively related to cortisol at lower levels of teacher-child closeness and unrelated at higher levels of teacher-child closeness. Findings suggest children's cortisol expression depends on the extent to which specific temperamental characteristics "fit" within the relational and contextual qualities of the classroom environment, particularly as children navigate the new roles and relationships that emerge during the transition to formal schooling. Developmentally informed neurobiological research in classrooms may contribute to tailored programmatic efforts to support children's school adjustment.

Socioeconomic Adversity, Negativity in the Parent Child-Relationship, and Physiological Reactivity: An Examination of Pathways and Interactive Processes Affecting Young Children's Physical Health.

OBJECTIVE: We tested the hypothesis that socioeconomic status (SES) would predict children's physical health problems at the end of kindergarten among children whose parent reported greater parent-child relationship (PCR) negativity and/or who exhibited greater parasympathetic (RSA) reactivity. We also tested whether RSA and PCR negativity mediated the SES-health association. METHODS: Data were collected from 338 children (mean [SD] age, 5.32 [.32] years) and their primary caregivers (87% biological mothers) during the fall and subsequent spring of kindergarten. In the fall, parents reported income and education level (SES) and PCR negativity, and RSA reactivity was assessed via a standardized challenge protocol for young children. In the fall and then spring, parents reported children's chronic medical conditions and physical health impairments. Multivariate regression was conducted within a structural equation-modeling framework to test hypotheses. RESULTS: Significant interactions were found between SES and PCR negativity (b = -0.074, p = .035) and between SES and RSA reactivity (b = 0.169, p = .019) as predicts children's spring health impairment, adjusting for health in the preceding fall. Lower SES was associated with greater health impairment among children whose parents reported more PCR negativity (b = -0.110, p = .024) and children who showed greater RSA reactivity (b = -0.106, p = .011). Socioeconomic status was unrelated to physical health at low PCR negativity or RSA reactivity. Mediation models were not supported. CONCLUSION: Parent-child relationship quality and individual differences in stress reactivity may modulate the influence of SES on physical health in childhood.