The Arizona Twin Project is an ongoing longitudinal study designed to elucidate gene–environment interplay underlying the development of risk and resilience to common mental and physical health problems during infancy, childhood and adolescence. Specificity of risk is carefully examined across mental and physical health and how these influences vary across socioeconomic and sociocultural environments. Participants are a sample of approximately 700 twins (31% Latinx) recruited from birth records in the state of Arizona, USA. Twins are 32% monozygotic twins, 36% same-sex dizygotic (DZ), 32% opposite-sex DZ, currently 10–11 years of age. Primary caregivers were interviewed on twins’ development and early physical and social environments when twins were 1, 2 and 5 years of age. In-depth objective measurement commenced in middle childhood, with in-person assessments at 8–11 years of age, with plans to continue to follow the sample across adolescence. Middle childhood measures focus on children’s physical and mental health, including diurnal cortisol, actigraphy-based measures of sleep and activity, cold pressor task assessing acute pain, and reaction time tasks assessing executive functioning. Preliminary findings illustrate that objective assessments of children’s health are highly heritable, but they do not always share genetic etiology with more commonly used subjective assessments. Exposure to early adversity moderates genetic influences on both executive functioning and health, with higher heritability typically seen under adverse conditions. Future directions include an examination of how pubertal stage affects genetic and environmental influences on diurnal cortisol, sleep, chronic pain, and mental health.

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Inhibitory control skills are important for academic outcomes across childhood, but it is unknown whether inhibitory control is implicated in the association between genetic variation and academic performance. This study examined the relationship between a GWAS-based (EduYears) polygenic score indexing educational attainment (EA PGS) and inhibitory control in early (M age = 3.80 years) and middle childhood (M age = 9.18 years), and whether inhibitory control in early childhood mediated the relation between EA PGS and academic skills. The sample comprised 731 low-income and racially/ethnically diverse children and their families from the longitudinal early steps multisite study. EA PGS predicted middle childhood inhibitory control (estimate = 0.09, SE = 0.05, p < 0.05) and academic skills (estimate = 0.18, SE = 0.05, p < 0.01) but did not predict early childhood inhibitory control (estimate = 0.08, SE = 0.05, p = 0.11); thus, mediation was not tested. Sensitivity analyses showed that effect sizes were similar across European and African American groups. This study suggests that inhibitory control could serve as a potential mechanism linking genetic differences to educational outcomes.

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This study is a secondary data analysis that extends knowledge about the effects of the early childhood Family Check-Up (FCU) intervention to trajectories of general psychopathology problems (p factor) across early and middle childhood, and effects on adolescent psychopathology and polydrug use. The Early Steps Multisite study (ClinicalTrials.gov Identifier NCT00538252) is a randomized controlled trial of the FCU and consists of a large, racially and ethnically diverse sample of children who grew up in low-income households in Pittsburgh, Pennsylvania; Eugene, Oregon; and Charlottesville, Virginia (n = 731; 49% female; 27.6% African American, 46.7% European American, 13.3% Hispanic/Latinx). To represent a comorbid presentation of internalizing and externalizing problems, we fit a bifactor model that included a general psychopathology (p) factor at eight ages in early childhood (ages 2–4), middle childhood (ages 7.5–10.5), and adolescence (age 14). Latent growth curve modeling was conducted to examine trajectories of the p factor across ages within the developmental periods of early and middle childhood. The effects of FCU on the reductions in growth in the childhood p factor had cascading effects on adolescent p factor (i.e., within-domain effect) and polydrug use (i.e., across-domain effect). Findings underscore the utility of the early FCU in preventing a host of maladaptive adolescent outcomes across diverse settings and populations.