Obstetrical and Neonatal Complications, Prematurity, and Childhood Effortful Control Development: A Longitudinal Twin Study

Background: Premature infants may be at risk for lower effortful control, and subsequent lower academic achievement, peer competence, and emotional and physical wellness throughout the lifespan. However, because prematurity is related to obstetrical and neonatal complications, it is unclear what may drive the effect. Effortful control also has a strong heritable component; therefore, environmental factors during pregnancy and the neonatal period may interact with genetic factors to predict effortful control development. In this study, I aimed to dissect the influences of genetics, prematurity, and neonatal and obstetrical complications on the development of effortful control from 12 months to 10 years using a twin cohort. Methods: This study used data from the Arizona Twin Project, an ongoing longitudinal study of approximately 350 pairs of twins. Twins were primarily Hispanic/Latinx (23.8%-27.1%) and non-Hispanic/Latinx White (53.2%-57.8%), and families ranged in socioeconomic status with around one-third falling below or near the poverty line. Of the twins, 62.6% were born prematurely. Effortful control was assessed via parent report at six waves. Results: There was not a significant relationship between gestational age and effortful control regardless of whether obstetrical and neonatal complications were controlled for. Biometric twin modeling revealed that the attentional focusing subdomain of effortful control was highly heritable. Gestational age did not moderate genetic and environmental estimates. Conclusions: The findings help inform the risk assessment of prematurity and provide evidence for differing etiology of each subdomain of effortful control and the strong role of genetics in effortful control development.