Sleep and weight health during childhood can be the essential building blocks that influence later physical and psychological health. Researchers note how neighborhood effects on health may be mediated or moderated by parenting or family-related factors. This dissertation expanded on the efforts through an examination of contextual predictors of children’s health using the Arizona Twin Project dataset (N = 933; 51.7% female; 56.5% White; 25.6% Latino). The family stress model (FSM), contextual relevance model (CRM), and the integrated model were used to test the relations between neighborhood and family factors on children sleep and weight health. Parent perceptions of neighborhood danger and childhood opportunities index were tested using multilevel- mediation, moderation, and moderated mediation models to address some of the limitations in previous reviews. The FSM was partially supported: parental stress and strain mediated the association between perceived neighborhood danger with sleep efficiency. However, the FSM was not fully supported as parental stress and disrupted parenting did not serially mediate the associations between neighborhood conditions and sleep efficiency. Moderation analyses revealed that negative parenting exacerbates associations between perceived neighborhood danger and sleep duration, demonstrating amplified disadvantages processes of the CRM. Negative parenting also moderated the associations between perceived neighborhood danger and sleep efficiency; the relationship was beyond what was noted in the CRM. Greater neighborhood opportunity was more strongly related to greater body fat percentage in families with higher positive parenting, as compared to families with lower positive parenting. Familism significantly moderated the association between neighborhood contexts and parental stress and strain within a subsample (Latino descent only). Last, the exploratory multilevel moderated mediation models suggested that most associations did not vary by the subgroups explored (i.e., positive parenting, familism cultural value). These results join a growing initiative to explore the science of ecological context, culture, and family interplay.

Prior research has established associations between sleep duration and body mass index (BMI) scores and risk for obesity in middle childhood, but it is less clear whether other objectively- and subjectively-measured sleep indicators may be associated with BMI scores, weight status (e.g., obesity), and other estimates of weight and body fat such as waist circumference (WC) and percent body fat. Empirical studies have also demonstrated independent associations between broad self-regulation and sleep indicators and BMI scores, but no study to date has tested these factors in a model together and the extent to which associations between normative sleep problems, weight indicators, and effortful control (EC) may be explained by shared genetic or environmental influences. Data from a large longitudinal study of twins was used to test phenotypic associations between sleep problems at eight years and weight indicators at nine years, including whether EC at eight years moderates these associations. Additionally, multiple quantitative behavior genetic models were used to estimate unique and shared genetic and environmental covariances among normative sleep problems, weight indicators, and EC at eight years of age and whether additive genetic influence on weight in middle childhood differs by child weight status group. Phenotypic findings showed that greater sleep duration at eight years predicted greater decreases BMI at nine years of age for children with low levels of EC at eight years. Greater sleep midpoint variability at eight years predicted greater increases in percent body fat from eight to nine years of age for children with low EC at eight years. Behavior genetic findings showed greater environmental influences on parent-reported sleep duration and quality, as well as objective sleep midpoint variability. Similarly, associations between parent-reported sleep duration and sleep midpoint variability and other sleep indicators and EC were primarily accounted for by shared environmental factors. In contrast, there was high additive genetic influence on objective sleep quantity and quality, all weight indicators, and EC. Many of the associations between sleep indicators, sleep and weight indicators, and among weight indicators were entirely accounted for by shared additive genetic factors, suggesting that common, underlying sets of genes explain these relations.

This dissertation examined how anxiety levels and social competence change across the course of early elementary school, as well as how individual differences at the transition to kindergarten may influence these trajectories. Previous research has supported unidirectional relations among anxiety and social competence, but few studies explore how inter- and intra-individual changes in social competence and anxiety may be related across time. From a developmental perspective, studying these trajectories following the transition to kindergarten is important, as cognitive and emotion regulation capacities increase markedly across kindergarten, and the relative success with which children navigate this transition can have a bearing on future social and emotional functioning across elementary school. In addition, given gender differences in anxiety manifestation and social competence development broadly, gender differences were also examined in an exploratory manner. Data from parent and teacher reports of a community sample of 291 children across kindergarten, 1st, and 2nd grades were analyzed. Results from bivariate growth models revealed steeper increases in anxiety, relative to peers in the sample, were associated with steeper decreases in social competence across time. This finding held after controlling for externalizing behavior problems at each time point, which suggests that relations among anxiety and social competence may be independent of other behavior problems commonly associated with poor social adjustment. Temperament variables were associated with changes in social competence, such that purportedly "risky" temperament traits of higher negative emotionality and lower attention control were associated with concurrently lower social competence in kindergarten, but with relatively steeper increases in social competence across time. Temperament variables in kindergarten were unrelated with changes in anxiety across time. Gender differences in relations among anxiety in kindergarten and growth in social competence also were revealed. Findings for teacher and parent reports of child behavior varied. Results are discussed with respect to contexts that may drive differences between parent and teacher reports of child behavior, as well as key developmental considerations that may help to explain why kindergarten temperament variables examined herein appear to predict changes in social competence but not changes in anxiety levels.

In this dissertation Mexican American (MA) youths environmental risk contexts, HPA axis functioning and mental health symptomatology were investigated in two separate studies. In the first study, environmental risk contexts were examined utilizing a person-centered approach and focusing on MA adolescents' family, peer, and cultural risk factors in fifth grade (N = 750). Environmental contexts were then linked to mental health symptomatology in seventh grade. Results revealed three distinct environmental contexts: Low risk, Moderate risk-language, and High risk-peer. Youth in the High-risk peer context reported the highest levels of symptomatology; greater major depressive disorder (MDD), anxiety, conduct disorder (CD)/oppositional defiant disorder (ODD), and attention deficit hyperactive disorder (ADHD) symptoms than youth experiencing Low risk or Moderate risk-language context. Females, in particular, experiencing the High risk peer context appeared at greatest risk for MDD symptoms. Finally, adolescents in the Moderate risk-language context displayed similar levels of symptoms to the individuals in the Low risk context, with the exception of higher anxiety. This study suggested that MA youth live in unique environmental contexts and these contexts are differentially related to mental health symptomatology. In the second study, 98 MA youth participated in a three-day diurnal cortisol protocol in hopes of linking perceptions of discrimination and HPA diurnal cortisol rhythms. Results revealed that discrimination was related to greater overall cortisol output and marginally related to the cortisol awakening response and evening levels of cortisol. Results suggest that important physiological processes underlie the experiences of discrimination.