Novel Measures of Culture and Their Relation to Self-regulation in Middle Childhood: A Genetically Informed Twin Study

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Description
It has been theorized that cultural variation within the family shapes children’s self-regulatory competence, yet there is a dearth of research examining the relation between culture and self-regulation. Family orientation refers to the emphasis on providing support, respect, and obligation

It has been theorized that cultural variation within the family shapes children’s self-regulatory competence, yet there is a dearth of research examining the relation between culture and self-regulation. Family orientation refers to the emphasis on providing support, respect, and obligation to the family system, and is important for children’s functioning, yet existing literature on related constructs relies on parent-reported measures. Additionally, quantitative genetic research has neglected the role of culture in the genetic and environmental contributions on children’s self-regulation. There were three main aims of this study: 1) to propose novel coding schemes and factor analytic approaches to capture family orientation, 2) to examine the relation between family orientation and self-regulation in middle childhood, and 3) to examine whether family orientation moderates the genetic and environmental influences on self-regulation in middle childhood. The sample was drawn from the Arizona Twin Project (N=710) where children (49.1% female, 55.6% White, 28.3% Hispanic/Latino) were assessed at approximately eight years of age (Mage = 8.38 years, SD = 0.66). Family orientation values were indexed by parent-reported familism, whereas family orientation behaviors comprised coded measures of children’s family orientation and experimenter ratings of caregiver and child behavior. Outcome measures of self-regulation included the Continuous Performance Task, Flanker Task, Digit Span Backward, and parent- and teacher-reported effortful control (Temperament in Middle Childhood Questionnaire). Higher family orientation behaviors predicted positively predicted children’s self-regulation, with the exception of Digit Span Backward performance, and associations were not moderated by child sex, family SES, or race/ethnicity. Twin models revealed that differences in family orientation behaviors could be attributed to genetic, shared, and nonshared environmental influences, and additive genetic and nonshared environmental influences explained the variation across measures of self-regulation. Finally, there was no evidence that family orientation values nor behaviors moderated the genetic or environmental influences on children’s self-regulation. This study highlights the complex nature of cultural variation within the family and its importance for children’s self-regulatory abilities.
Date Created
2022
Agent

Diet, Physical Activity, and ADHD Symptoms in Middle Childhood: Shared and Unique Environmental and Genetic Influences

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Description

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

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.

Date Created
2021-12
Agent

Genetic and Environmental Influences on Executive Functioning in Middle Childhood: The Role of Early Adversity

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Description
This study examined whether early adversity at 30-months moderated the heritability of common and individual components of EF at 8 years. It was hypothesized that early adversity would not moderate the common EF factor, but instead moderate individual EF components.

This study examined whether early adversity at 30-months moderated the heritability of common and individual components of EF at 8 years. It was hypothesized that early adversity would not moderate the common EF factor, but instead moderate individual EF components. The sample included 208 twin pairs from the Arizona Twin Project. Early Adversity, assessed at 30 months of age, included Parenting Daily Hassles, low perceived MOS social support, punitive punishment (Parental Responses to Child Misbehavior), home chaos (Confusion, Hubbub, and Order Scale), CES-D maternal depression, and low maternal emotional availability. EF at 8 years included the Eriksen Flanker Task, Continuous Performance Task, Digit Span Forward and Backward, and parent-reported Attentional Focusing and Inhibitory Control (Temperament in Middle Childhood Questionnaire). For both early adversity and EF, the first principal components were extracted as composites. A confirmatory factor analysis was also conducted to index common EF. Genetic analyses were tested on the common EF composites as well as each individual task using umx. Univariate models revealed genetic influences on all individual measures and common EF, with broad sense heritability from .22 (Digit Span Backwards) to .61 (parent-reported inhibitory control). Shared environmental influences were found for the Flanker Task (.13) and parent-reported inhibitory control (.24), and E was moderate to high (.40-.73) for all measures except parent-report inhibitory control (.15) and attentional focusing (.31). Moderation of heritability was not observed in for Digit Span Forward, Digit Span Backward, and Attentional Focusing. However, the nonshared environment was moderated for Common EF, and the Flanker Task, and additive genes and the nonshared environment were moderated for the Continuous Performance Task and Inhibitory Control. Generally, total variance decreased as early adversity increased, suggesting that homes with low levels of adversity may allow children to interact with more proximal processes that can promote EF development.
Date Created
2018
Agent