Sociodemographic risk, parenting, and effortful control: relations to salivary alpha-amylase and cortisol in early childhood

Non-Intrusive Maternal Style as a Mediator between Playfulness and Children’s Development for Low-Income Chilean Adolescent Mothers

The aim of this study was to describe the relationship between low-income Chilean adolescent maternal playfulness and mothers’ non-intrusiveness in their children’s development and to analyze whether a mother’s non-intrusiveness mediates the relationship between maternal playfulness and children’s development. The Parental Playfulness Scale and the Subscale of Intrusiveness from the Early Head Start Research and Evaluation Project were used to assess maternal playfulness and mothers’ non-intrusiveness respectively. Ages and Stages Questionnaire 3rd Edition (ASQ-3) was applied to measure the children’s communication, gross and fine motor skills, problem-solving and personal–social development. The sample consisted of 79 mother–child dyads with children aged 10–24 months (M = 15.5, SD = 4.2) and their mothers aged 15–21 years old (M = 19.1, SD = 1.7). A bivariate analysis showed that maternal playfulness was significantly associated with communication, fine motor, problem-solving and personal–social development. Moreover, higher levels of communication, fine motor skills and problem-solving development were observed in the children of less intrusive mothers. Maternal playfulness had a significant effect on children’s development of language, problem-solving and personal–social skills when their mothers showed less intrusiveness during interaction. These findings contribute to the understanding of the interaction between adolescent mothers and their children. Active play and less intrusiveness can enhance child development.

Early childhood stress responses to psychosocial stressors: The state of the science

The aim of this systematic review was to better understand whether and to what extent psychosocial stressors are associated with hypothalamic-pituitary-adrenal axis or autonomic nervous system stress responses in young children (1-6 years of age). Studies were classified by psychosocial stressors from the ecobiodevelopmental model: social and economic resources, maternal mental health, parent-child relationships, and the physical environment. Of the 2388 identified studies, 32 met full inclusion criteria, including over 9107 children. Child physiologic stress responses were measured as hair and urinary cortisol and cortisone, salivary diurnal and reactive cortisol, salivary reactive alpha-amylase, and respiratory sinus arrhythmia. There were 107 identified relations between psychosocial stressors and physiologic stress responses. Nearly two thirds of these relations suggested that children have dysregulated stress responses as either significantly blunted (n = 27) or increased (n = 37); 43 relations were not significant. Children most consistently had significantly dysregulated stress responses if they experienced postnatal maternal depression or anxiety. Some reasons for the mixed findings may be related to characteristics of the child (i.e., moderators) or stressor, how the stress response or psychosocial stressor was measured, unmeasured variables (e.g., caregiving buffering), researcher degrees of freedom, or publication bias.

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.

Pediatric Traumatic Brain Injury: An Update on Preclinical Models, Clinical Biomarkers, and the Implications of Cerebrovascular Dysfunction

Traumatic brain injury (TBI) is a leading cause of pediatric morbidity and mortality. Recent studies suggest that children and adolescents have worse post-TBI outcomes and take longer to recover than adults. However, the pathophysiology and progression of TBI in the pediatric population are studied to a far lesser extent compared to the adult population. Common causes of TBI in children are falls, sports/recreation-related injuries, non-accidental trauma, and motor vehicle-related injuries. A fundamental understanding of TBI pathophysiology is crucial in preventing long-term brain injury sequelae. Animal models of TBI have played an essential role in addressing the knowledge gaps relating to pTBI pathophysiology. Moreover, a better understanding of clinical biomarkers is crucial to diagnose pTBI and accurately predict long-term outcomes. This review examines the current preclinical models of pTBI, the implications of pTBI on the brain's vasculature, and clinical pTBI biomarkers. Finally, we conclude the review by speculating on the emerging role of the gut-brain axis in pTBI pathophysiology.

A mother's touch: Preschool-aged children are regulated by positive maternal touch

Positive maternal touch plays an important role in the development of children's physiological regulation and cognitive development in infancy, as well as the development of sociality in early childhood. However, few studies have looked beyond infancy to consider the possible continuing impact of positive maternal touch on child stress reactivity during early childhood. A diverse community sample of mothers (N = 114, M_age  = 33.52 years, SD = 5.33) and their preschool-aged children (M_age  = 41.68 months, SD = 4.67; 49.1% female) participated in the study. Basic demographics were reported by mothers. We coded maternal touch behaviors during an emotionally charged laboratory conversation task and assessed children's physiological reactivity to stressful laboratory tasks with salivary cortisol. Results reveal a significant negative association between positive maternal touch and child salivary cortisol reactivity. In addition, family income, adjusted for family size, and child sex were significantly associated with child cortisol stress reactivity. Findings are discussed in terms of persistent downregulating effects of positive maternal touch on child stress reactivity, as well as possible links of stress reactivity with family income, a proxy for economic stress, and child sex.

Maternal sensitivity and intrusiveness in early childhood as predictors of children's weight at school age

BACKGROUND

While previous research indicates that low maternal sensitivity in mother-child interactions puts children at risk of overweight and obesity, maternal intrusiveness has rarely been investigated in association with children's weight. We investigated whether maternal sensitivity and intrusiveness in early childhood predict children's increased body mass index standard deviation scores (BMI-SDS) at school age. BMI-SDS are standardized for age and gender with respect to a reference standard.

METHODS

At baseline (t1), we assessed maternal sensitivity and (non-)intrusiveness of 116 mothers with their children (48.3% female) aged 5-47 months (M = 24.00, SD = 11.36) using the emotional availability scales. We obtained anthropometric data for mothers at t1 by measuring height and weight in the laboratory and for children at birth assessed by medical staff. Six years later (t2) we obtained anthropometric data for children in the laboratory or based on parental report. Linear regression analyses were run with child BMI-SDS at t2 as outcome and sensitivity and (non-)intrusiveness as predictors, adjusting for confounders and exploring child age and gender as moderators.

RESULTS

Maternal sensitivity only negatively predicted children's BMI-SDS in girls, while maternal intrusiveness predicted higher child BMI-SDS at school age regardless of child gender. The effect of maternal non-intrusiveness remained significant when controlling for confounders.

CONCLUSION

Maternal intrusiveness in early childhood seems to represent a risk factor for increased BMI-SDS in children, while lower maternal sensitivity tends to be a risk factor for increased BMI-SDS in girls. This may have implications for prevention or intervention programmes.

Associations between hair and salivary cortisol, salivary alpha-amylase, and temperament dimensions among 3-6-year-olds

Associations between hair cortisol concentration (HCC), diurnal salivary cortisol (sCort) and alpha-amylase (sAA), and temperament dimensions were examined among 3-6-year-old Finnish children (n = 833). Children's hair samples were collected at preschool, while parents collected five saliva samples from children during one weekend day and completed a questionnaire assessing child's temperament dimensions i.e. surgency, negative affectivity, and effortful control (HCC, n = 677; AUCg of sAA, n = 380; AUCg of sCort, n = 302; temperament dimensions, n = 751). In linear regression analysis, diurnal sCort associated positively with HCC, the association persisting after adjustments (β 0.31, 95% CI 0.20-0.42). In logistic regression analysis, increasing scores in effortful control associated with higher likelihood of having high HCC (OR 1.47, 95% CI 1.07-2.03), the association slightly attenuating to non-significant after adjustments. Otherwise, no clear indication for associations between temperament and stress-related biomarkers were found.

Externalizing behavior and stress system functioning in infants exposed to early adversity: A multi-system exploration

Children who experience early adversity often show alterations across multiple stress response systems, including the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). Changes in the diurnal rhythm of salivary cortisol (a marker of HPA axis functioning) and alpha-amylase (a marker of ANS functioning) may increase their probability of developing behavior problems. The goal of this study is to examine how these analytes may interact to predict externalizing behavior in infants exposed to early stress. Participants included 179 parents and their 6- to 20-month old infants recruited from a low-income neighborhood. Parents reported on their infants' externalizing behaviors and collected saliva samples from their children at wake-up and bedtime over three days. Diurnal cortisol and alpha-amylase were modeled using latent difference scores. Four models were tested examining the effects of cortisol and alpha-amylase morning values and slopes, as well as their interactions, on externalizing behavior. Results showed a significant interaction effect of cortisol and alpha-amylase morning values, such that low morning cortisol was associated with decreased externalizing behavior when morning alpha-amylase was high but not low. These findings highlight the importance of examining multiple systems when characterizing the physiological correlates of externalizing behavior among infants experiencing adversity.

Biological sensitivity to context: A test of the hypothesized U-shaped relation between early adversity and stress responsivity

We conducted signal detection analyses to test for curvilinear, U-shaped relations between early experiences of adversity and heightened physiological responses to challenge, as proposed by biological sensitivity to context theory. Based on analysis of an ethnically diverse sample of 338 kindergarten children (4-6 years old) and their families, we identified levels and types of adversity that, singly and interactively, predicted high (top 25%) and low (bottom 25%) rates of stress reactivity. The results offered support for the hypothesized U-shaped curve and conceptually replicated and extended the work of Ellis, Essex, and Boyce (2005). Across both sympathetic and adrenocortical systems, a disproportionate number of children growing up under conditions characterized by either low or high adversity (as indexed by restrictive parenting, family stress, and family economic condition) displayed heightened stress reactivity, compared with peers growing up under conditions of moderate adversity. Finally, as hypothesized by the adaptive calibration model, a disproportionate number of children who experienced exceptionally stressful family conditions displayed blunted cortisol reactivity to stress.

Inhibitory Control Across the Preschool Years: Developmental Changes and Associations with Parenting

The normative developmental course of inhibitory control between 2.5 and 6.5 years, and associations with maternal and paternal sensitivity and intrusiveness were tested. The sample consisted of 383 children (52.5% boys). During four annual waves, mothers and fathers reported on their children’s inhibitory control using the Children's Behavior Questionnaire. During the first wave, mothers’ and fathers’ sensitivity and intrusiveness were observed and coded with the Emotional Availability Scales. Inhibitory control exhibited partial scalar invariance over time, and increased in a decelerating rate. For both mothers and fathers, higher levels of sensitivity were associated with a higher initial level of children's inhibitory control, whereas higher levels of intrusiveness predicted a slower increase in children's inhibitory control.

Poverty, Caregiving, and HPA-Axis Activity in Early Childhood

The association between poverty and the activity of the hypothalamic pituitary adrenal (HPA) axis in early childhood is well established. Both ecological and transactional theories suggest that one way in which poverty may influence children's HPA-axis activity is through its effects on parents' behaviors, and over the past three decades a substantial literature has accumulated indicating that variations in these behaviors are associated with individual differences in young children's HPA-axis activity. More recent research suggests that non-parental caregiving behaviors are associated with HPA-axis activity in early childhood as well. Here we systematically review the literature on the association between both parental and non-parental caregiving behaviors in the context of poverty and the activity of the HPA-axis in early childhood. We conclude by noting commonalities across these two literatures and their implications for future research.

Interrelatedness of Children's Psychological and Physiological Responses to Interparental Conflict: A Moderating Role of Harsh Parenting

Children's psychological and physiological responses to interparental conflict have received considerable attention due to their implications for later adjustment, yet limited research has investigated the interplay between these two response systems. This study investigates patterns of association between children's psychological responses (e.g., emotional distress) and cortisol reactivity to interparental conflict, including possible moderations by negative caregiving environment. Participants included 193 families (mother, father, and child). Parents completed questionnaires relating to their caregiving behaviors toward the child (107 girls and 86 boys, M age = 7.99 years, SD = 0.53 years) and children's psychological responses to interparental conflict. Children provided three saliva samples over the course of watching videos depicting conflicts between two adults, whom children were asked to pretend were their parents. Based on a series of Latent Growth Curve Models, only children's emotional responses to interparental conflict (indicated by increased distress) were associated with greater cortisol reactivity. Additionally, fathers' harsh parenting behavior moderated the relation between children's emotional reactivity and cortisol reactivity, yet the moderation effect was not found for mothers' parenting. Findings are discussed in terms of the importance of exploring both psychological and physiological reactivity to conflict and the possible moderating role of harsh parenting.

Socioeconomic risk moderates the association between caregiver cortisol levels and infant cortisol reactivity to emotion induction at 24 months

Relations between maternal baseline cortisol and infant cortisol reactivity to an emotion induction procedure at child ages 7, 15, and 24 months were analyzed using data from the Family Life Project (N = 1,292). The emotion induction consisted of a series of standardized and validated tasks, including an arm restraint, toy removal, and mask presentation, intended to elicit responses of fear and frustration. Results revealed that at 7 and 15 months, maternal baseline cortisol was negatively related to child cortisol reactivity, such that children of mothers with lower cortisol exhibited steeper cortisol increases in response to the emotion induction. At 24 months, the association between mother and infant cortisol was moderated by socioeconomic risk, such that maternal baseline cortisol was associated with child cortisol reactivity only in dyads characterized by low socioeconomic risk. Furthermore, at 24 months, children of mothers with low baseline cortisol and low socioeconomic risk exhibited decreasing cortisol responses, whereas children of mothers with low baseline cortisol but high risk exhibited flat cortisol responses. Children in dyads characterized by high baseline maternal cortisol also exhibited flat cortisol responses regardless of socioeconomic risk. The role of caregiver physiology in the regulation of the child's stress response in the context of adversity is discussed.

The impact of maternal stress on infant alpha-amylase is buffered by high infant regulation and low infant negative reactivity

This study examined the main and interactive effects of maternal perceived stress and infant temperament-surgency, negative affectivity, and orienting/regulation-on infant salivary alpha-amylase (sAA) responses to stress. Saliva samples were collected prior to and following two naturalistic stressors: maternal separation conducted at 9 months and blood draw/immunizations conducted at 12 months. sAA area under the curve (AUC) was computed to determine response of the sympathetic nervous system to each stressor. Results revealed significant interactions of maternal stress and infant negative affectivity and orienting/regulation with sAA AUC. Relations between maternal stress and infant sAA AUC were stronger among infants with higher levels of negative affectivity and lower levels of orienting/regulation. These results highlight the need to examine both infant characteristics and environmental factors when investigating the development of stress response systems.

Exposure to intimate partner violence in utero and infant internalizing behaviors: Moderation by salivary cortisol-alpha amylase asymmetry

Guided by the main tenets of contemporary models of the developmental origins of health and disease, this study evaluated whether individual differences in reactivity of the hypothalamic-pituitary-adrenal (HPA) axis and Sympathetic Nervous System (SNS) moderate the effect of prenatal exposure to trauma on internalizing and externalizing behaviors during infancy. Participants were a community sample of 182 mothers (M age=25years, 43% Caucasian, 33% Black/African American, 24% Biracial/Other) and their infants (59% girls; M age=11.8months). Each mother completed questionnaires that assessed IPV experienced during pregnancy and also reported on her infant's behavior problems. Infant saliva samples (later assayed for cortisol and sAA) were collected before and after a frustrating task (i.e., arm restraint). Results revealed that the association between in utero IPV and infant internalizing behaviors was most pronounced for infants with asymmetrical HPA-SNS (i.e., high-cortisol and low-sAA) reactivity to frustration, and least pronounced for infants with symmetrical HPA-SNS (i.e., low-cortisol and low-sAA or high-cortisol and high-sAA) reactivity to frustration. Higher levels of externalizing behavior, in contrast, were associated with higher levels of prenatal IPV but unrelated to either cortisol or sAA reactivity to stress. Findings replicate documented associations between maternal IPV exposure during pregnancy and offspring risk. Moreover, findings advance our understanding of individual differences in the developmental origins of health and disease and provide additional evidence that assessing multiple stress biomarkers contributes to a more comprehensive understanding of individual vulnerability to adversity.

Vascular impairment as a pathological mechanism underlying long-lasting cognitive dysfunction after pediatric traumatic brain injury

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Indeed, the acute mechanical injury often evolves to a chronic brain disorder with long-term cognitive, emotional and social dysfunction even in the case of mild TBI. Contrary to the commonly held idea that children show better recovery from injuries than adults, pediatric TBI patients actually have worse outcome than adults for the same injury severity. Acute trauma to the young brain likely interferes with the fine-tuned developmental processes and may give rise to long-lasting consequences on brain's function. This review will focus on cerebrovascular dysfunction as an important early event that may lead to long-term phenotypic changes in the brain after pediatric TBI. These, in turn may be associated with accelerated brain aging and cognitive dysfunction. Finally, since no effective treatments are currently available, understanding the unique pathophysiological mechanisms of pediatric TBI is crucial for the development of new therapeutic options.

Elementary Students' Effortful Control and Academic Achievement: The Mediating Role of Teacher-Student Relationship Quality

This study evaluated the association between effortful control in kindergarten and academic achievement one year later (N = 301), and whether teacher-student closeness and conflict in kindergarten mediated the association. Parents, teachers, and observers reported on children's effortful control, and teachers reported on their perceived levels of closeness and conflict with students. Students completed the passage comprehension and applied problems subtests of the Woodcock-Johnson tests of achievement, as well as a behavioral measure of effortful control. Analytical models predicting academic achievement were estimated using a structural equation model framework. Effortful control positively predicted academic achievement even when controlling for prior achievement and other covariates. Mediation hypotheses were tested in a separate model; effortful control positively predicted teacher-student closeness and strongly, negatively predicted teacher-student conflict. Teacher-student closeness and effortful control, but not teacher-student conflict, had small, positive associations with academic achievement. Effortful control also indirectly predicted higher academic achievement through its positive effect on teacher-student closeness and via its positive relation to early academic achievement. The findings suggest that teacher-student closeness is one mechanism by which effortful control is associated with academic achievement. Effortful control was also a consistent predictor of academic achievement, beyond prior achievement levels and controlling for teacher-student closeness and conflict, with implications for intervention programs on fostering regulation and achievement concurrently.

Concurrent and longitudinal associations of peers' acceptance with emotion and effortful control in kindergarten

The purpose of the study was to evaluate bidirectional associations between peer acceptance and both emotion and effortful control during kindergarten (N = 301). In both the fall and spring semesters, we obtained peer nominations of acceptance, measures of positive and negative emotion based on naturalistic observations in school (i.e., classroom, lunch/recess), and observers' reports of effortful control (i.e., inhibitory control, attention focusing) and emotions (i.e., positive, negative). In structural equation panel models, peer acceptance in fall predicted higher effortful control in spring. Effortful control in fall did not predict peer acceptance in spring. Negative emotion predicted lower peer acceptance across time for girls but not for boys. Peer acceptance did not predict negative or positive emotion over time. In addition, we tested interactions between positive or negative emotion and effortful control predicting peer acceptance. Positive emotion predicted higher peer acceptance for children low in effortful control.

Infant hair cortisol: associations with salivary cortisol and environmental context

Early chronic stress has enduring implications for physical and mental health outcomes. Hair cortisol concentration (HCC) has emerged as a marker of cumulative cortisol exposure, yet HCC in infants is not well understood. We examined how infant HCC relates to widely used basal salivary cortisol measures, maternal HCC, and environmental context in 111 infants assessed at 6 and 12 months of age. Maternal HCC at 6 and 12 months was correlated with infant HCC at 12 months. At 12 months, infant HCC was positively associated with waking salivary cortisol concentration (SCC), evening SCC, and area under the curve (AUC), but was independent of diurnal slope. Breastfeeding was associated with lower HCC, whereas increased sleep disruption was related to flatter slope. Reduced nighttime sleep duration was related both to higher HCC and to flatter slope. A person-focused analysis indicated that the combination of high HCC and flattened slope was associated with more environmental risks, highlighting the importance of investigating the interplay between HCC and diurnal cortisol slope. Results support the validity of HCC as a marker of cumulative cortisol exposure in infancy, while emphasizing the value of including multiple cortisol measures assessing distinct aspects of hypothalamic-pituitary-adrenal (HPA) function.

Interaction of adrenocortical activity and autonomic arousal on children's externalizing and internalizing behavior problems

The psychobiology of stress involves two major components, the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS). Research has revealed the association between behavior problems and the psychobiology of stress, yet findings are inconsistent and few studies have addressed the moderate correlations between behavior problems. This study examines the individual and interactive effects of HPA and ANS on child behavior problems while taking into account the comorbidity of externalizing and internalizing problems. Four saliva samples were collected from each participant in a community sample (N = 429; aged 11-12 years; 50.49 % male), which were assayed for cortisol (HPA) and alpha-amylase, sAA (ANS). Children's behavior problems were assessed using parent-report and self-report versions of the Child Behavior Checklist. Latent variables were constructed to represent trait-like individual differences in cortisol and sAA. Low levels of HPA axis activity were associated with higher levels of both externalizing and internalizing problems, but only among children with low ANS arousal. The association between externalizing and internalizing problems diminished to non-significant after taking into account the influence of HPA axis activity and ANS arousal, which suggests that the psychobiology of stress explains a fair proportion of comorbidity of behavior problems. The findings support that interaction between HPA axis and ANS functioning has potential to clarify prior mixed findings and advance our understanding of the child behavior problems.

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.

Greater fear reactivity and psychophysiological hyperactivity among infants with later conduct problems and callous-unemotional traits

BACKGROUND

Approximately one third of children who meet criteria for conduct problems (CP) are also characterized by elevated callous-unemotional (CU) traits. This subgroup is at elevated risk for more pervasive and extreme levels of later antisocial behavior and has been characterized by a fearlessness temperament and blunted stress psychophysiology at older ages. The objective of this study was to examine group differences in fear reactivity and stress psychophysiology in infancy among children classified as having CP with CU (CP + CU), CP without CU (CP only), or no CP in later childhood.

METHODS

A birth cohort study (n = 1,292) was followed longitudinally from birth through first grade. Behavioral fear, baseline heart period (HP) and respiratory sinus arrhythmia (RSA), and pretask, 20-min posttask, and 40-min posttask salivary cortisol were assessed at 6 and 15 months of age around a fear challenge task. CP and CU were assessed by maternal report at first grade and children were classified into CP and CU groups if they scored in the upper 10(th) percentile of these ratings.

RESULTS

No group differences were observed in children at 6 months of age. However, at 15 months of age children with later CP + CU displayed greater high-intensity fear behavior, higher pretask and overall cortisol levels, and lower levels of HP and RSA compared to children with CP only and children with no CP.

CONCLUSIONS

The discrepancy between the biobehavioral correlates of conduct problems with callous-unemotional traits in infancy and those reported from studies of older children and adults suggests that the etiology of this behavioral phenotype may be more complex than a simple genetic maturation model.

The Origins of Neuroticism

In this article, we provide a fresh perspective on the developmental origins of neuroticism—a dimension of temperament marked by elevated stress reactivity resulting in the frequent experience of negative emotions. This negative affectivity is accompanied by a pervasive perception that the world is a dangerous and threatening place, along with beliefs about one’s inability to manage or cope with challenging events. Historically, neuroticism has been viewed as a stable, genetically based trait. However, recent understanding of ongoing gene–environment interactions that occur throughout the life span suggests there may be a more complex and dynamic etiology. Thus, the purpose of this article is to offer a theory for understanding the development of neuroticism that integrates genetic, neurobiological, and environmental contributions to this trait. Given the strong correlation between neuroticism and the development of negative health outcomes—most notably, the full range of anxiety and mood disorders—an enhanced understanding of how neuroticism originates has implications for the treatment and prevention of a broad range of pathologies and, perhaps, even for the prevention of neuroticism itself.

Predicting developmental changes in internalizing symptoms: examining the interplay between parenting and neuroendocrine stress reactivity

In this study, we examined whether parenting and HPA-axis reactivity during middle childhood predicted increases in internalizing symptoms during the transition to adolescence, and whether HPA-axis reactivity mediated the impact of parenting on internalizing symptoms. The study included 65 children (35 boys) who were assessed at age 5, 7, and 11. Parenting behaviors were assessed via parent report at age 5 and 11. The child's HPA-axis reactivity was measured at age 7 via a stress task. Internalizing symptoms were measured via teacher reports at age 5 and 11. High maternal warmth at age 5 predicted lower internalizing symptoms at age 11. Also, high reported maternal warmth and induction predicted lower HPA-axis reactivity. Additionally, greater HPA-axis reactivity at age 7 was associated with greater increases in internalizing symptoms from age 5 to 11. Finally, the association between age 5 maternal warmth and age 11 internalizing symptoms was partially mediated by lower cortisol in response to the stress task. Thus, parenting behaviors in early development may influence the physiological stress response system and therefore buffer the development of internalizing symptoms during preadolescence when risk for disorder onset is high.