This study aimed to develop a measurement model for executive function (EF) in middle childhood for a low-income Mexican American sample and to elucidate dynamic change processes among measurable developmental correlates of EF during infancy and early toddlerhood as predictors of later higher-order EF abilities. Drawing from developmental theory and a model of neurovisceral integration, surges in neurocognitive regulatory abilities may be supported by both previous and concurrent changes in physiological functioning and engagement in reciprocal social relationships. Utilizing recent methodological innovations, the current study moved beyond traditional growth models to evaluate possible points of attenuation and acceleration in dyadic reciprocity and vagal functioning over time as well as dynamic associations between these unfolding developmental processes. Data were collected from 322 low-income Mexican American children in the home at 24 weeks and in a laboratory space at ages 1, 1.5, 2, 3, and 6 years. A parent-report measure of executive function also was collected over the phone between child age 7.5 and 9 years. Results suggested that, in this sample, EF was best modeled at child age 6 years as a unidimensional construct. Findings also supported the importance of earlier dyadic reciprocity for later EF, but there was a lack of evidence supporting the theorized link between EF and earlier vagal functioning and codevelopment of vagal functioning and dyadic reciprocity. This study highlights the importance of including dyadic measures of parent-child contingencies in studies of EF development and, from a clinical perspective, the potential use of relationship-based, dyadic intervention and prevention models to support crucial development of EF skills central to everyday adaptive functioning.

Postpartum depression is recognized as the most common psychiatric disorder that appears in approximately 10-15% of women, with higher frequencies among low-income minority women. Past studies have revealed that depressive symptoms negatively impact child development and mother-child synchrony. The current study's purpose was to explore the effects of postpartum depressive symptoms on later dyadic dysregulation. The data was collected from Las Madres Nuevas' study, a longitudinal investigation. Participants were 322 Mexican and Mexican American mother-infant dyads from the Phoenix metropolitan area who were recruited though a Maricopa Integrated Health System (MIHS) prenatal clinic. The Edinburgh Postnatal Depression Scale (EPDS) was used to measure depression 6 weeks postpartum. Additionally, the dysregulation-coding scheme used at child's 24 months of age measured the children's, mothers', and dyads' regulatory skills throughout their interactions with each other. Linear regression analyses were the central analyses of this study. In the first regression analysis, results showed that mother's age at prenatal visit (p= 0.44), 6-week depression score (p= 0.37), mother's education (p= 0.77), and number of biological children (p= 0.28) did not significantly predict dyadic dysregulation at 24 months. The second linear regression analysis concluded that the 6-week depression score, mother's country of birth, the interaction of maternal depression and country of birth, mother's education, mother's age at prenatal visit, and number of biological children also did not predict dyadic dysregulation at 24 months. Although not statistically significant, the findings suggest that the Hispanic Paradox theory, conservation of native cultural values, and strong social support have protective effects in Mexican immigrant and Mexican American childbearing women.