Attention-deficit hyperactivity disorder (ADHD) is a developmental disorder categorized by symptoms of inattention, impulsivity, and/or hyperactivity. The onset of ADHD symptoms begin to appear in childhood, tend to be persistent into adulthood, and are associated with adverse physical and mental health outcomes (Caye et al., 2016; Yoshimasu et al., 2018). The current study examined the effects of health-promoting behavior (i.e., diet and physical activity) on ADHD symptoms in middle childhood. The sample consisted of 670 twins (30.1% monozygotic, 36.5% same-sex dizygotic, 32.3% opposite-sex dizygotic) from the ongoing longitudinal study, the Arizona Twin Project. The twin’s (51% female) diet, physical activity, and ADHD symptoms were assessed at age 8 (M = 8.45, SD = 0.69) and ADHD symptoms were assessed again at age 9 (M = 9.70, SD = 0.92). Mixed model regression analyses revealed that aspects of diet (i.e., protein, carbohydrates, and fiber) at age 8 negatively predicted ADHD symptoms at age 9. Similarly, sedentary behavior at age 8 negatively predicted ADHD symptoms at age 9, whereas moderate-to-vigorous activity at age 8 positively predicted ADHD symptoms at age 9. Univariate twin analyses revealed that certain aspects of diet (i.e., sugar, vegetable, and fruit consumption) were influenced by environmental factors whereas other aspects of diet (i.e., protein, carbohydrates, calories, fat, and fiber consumption) were influenced by both genetic and environmental factors. Both children’s sedentary behavior and moderate-to-vigorous activity were influenced primarily by genetic factors, with the remaining variance being attributed to non-shared environmental factors. Additive genetic influences explained the majority of the variance in ADHD symptoms. Future research should examine bidirectional effects of activity and diet on ADHD symptoms across childhood.

This study sought to determine if perceived neighborhood danger impacted children's sleep. The current study asks: how does perceived neighborhood danger impact children’s sleep both quantity and quality (duration and efficiency), could children’s physical activity mediate these associations, and how do genetic and environmental factors play into these relationships? Questionnaires, biological measurements, and actigraphy watch data were collected from 709 8-year-old Arizonan twins and their parents in order to calculate neighborhood safety, sedentary physical activity, moderate to vigorous physical activity, sleep duration, and sleep efficiency as well as covariates. It was concluded that perceived neighborhood danger does not directly impact children’s sleep duration and efficiency, children’s physical activity does not mediate the relation of perceived neighborhood danger and children’s sleep, but rather, perceived neighborhood danger indirectly impacts children’s sleep duration and efficiency through moderate to vigorous activity, and finally, that both sedentary and moderate to vigorous activity are heavily influenced by genetics.

Pediatric chronic pain is common and costly to children, their families, and society. Importantly, pediatric pain often persists into adulthood. Prior research suggests that parent chronic pain, particularly maternal pain, is a risk factor for the development of chronic pain in children. Existing evidence also suggests that parenting, including parental pain-related pain catastrophizing and general parenting style, are all associated with greater levels of chronic pain in children. The present study examined whether the prospective relations between parent and child pain differed between mothers and fathers, and whether parenting mediated or moderated the parent pain--child pain relations. It was hypothesized that 1a) both maternal and paternal chronic pain prospectively predicts child chronic pain, but that maternal pain would be a stronger predictor; 1b) having 0, 1, or 2 parents will increase the child’s risk of developing chronic pain; 2) maternal pain catastrophizing about their own (a) and their children’ pain (b) would mediate the relations between maternal and child pain; and 3) authoritarian parenting style (a) and negative parenting behaviors (b) would mediate the relationship between parent and child pain. Exploratory analyses tested the whether parental warmth predicted child pain, independent of mom pain. Regression models that account for twin dependency used longitudinal data collected from a sample of 895 twin children showed that maternal pain but not paternal pain predicted child pain. Maternal catastrophizing of her own pain, but not her child’s pain, significantly mediated the relation between maternal and child pain. However, maternal catastrophizing of her child’s pain predicted child pain at age 9, when controlling for child pain at age 8. All proposed relations between general parenting styles as well as warm parenting and child pain were not significant.

Executive functioning (EF) is the cognitive processing of goal-oriented actions that are predictive of important life functioning skills. Middle childhood is an important time for academic achievement and social development. Positive and negative parenting practices were examined in the prediction of several child executive functioning outcomes in middle childhood, this thesis further examined whether early life socioeconomic status moderated such associations. This sample consisted of 708 twins (32% monozygotic, 36% same-sex dizygotic, and 32% opposite-sex dizygotic) with ethnically and socioeconomically diverse backgrounds at two age points, 12 months old (M = 12.5 months, SD = 1.06) and 8 years old (M = 8.41, SD = .40).There was a significant negative main effect between negative parenting and CPT. Further, positive parenting interacted with SES to predict CPT and Digit Span Forward. A significant positive effect was identified between positive parenting and CPT in low SES families, but not high SES families. Interestingly, greater positive parenting was associated with lower Digit Span Forward in high SES families, but not low SES families. These findings suggest that while negative parenting was associated with worse EF across the entire sample, the relationship between positive parenting practices and executive functioning outcomes differed based on early life socioeconomic status. Future research should examine whether various domains of executive functioning may follow different developmental patterns.

Prior research has established a relation between parenting behaviors and symptoms of child psychopathology, and this association may be influenced by both genetic and environmental factors. Gene-environment correlation, or the influence of a child’s genes on the environment they receive, represents one possible mechanism through which genes and environment combine to influence child outcomes. This study examined evocative gene-environment correlation in the relation between parenting and symptoms of child psychopathology in a sample of 676 twins (51.5% female, 58.5% Caucasian, 23.7% Hispanic/Latinx, primarily middle class, MAge=8.43, SD=.62) recruited from Arizona birth records. Using univariate ACE twin biometric models, genetic influences were found to moderately contribute to internalizing symptoms (A=.47, C=.25, E=.28), while externalizing (A=.86, E=.14) and ADHD (A=.84, E=.16) symptoms were found to be highly heritable. The genetic influences for positive (C=.54, E=.46) and negative (C=.44, E=.56) parenting were smaller and found to be nonsignificant. The correlations between parenting and types of psychopathology were examined and bivariate Cholesky decompositions were conducted for statistically significant correlations. Negative parenting was moderately positively correlated with externalizing and ADHD symptoms; the relation between externalizing symptoms and negative parenting was found to be due to shared genetics, whereas the relation between negative parenting and ADHD symptoms was due to the shared environment. The mixed results regarding the role of gene environment correlation in relations between parenting and child psychopathology indicate that further research on the mechanisms of this relation is needed.