Supporting the Self-Regulating Brain: The early developmental shift from external to internal self-regulation

The overarching aim of this dissertation was to examine the possible predictors and underlying mechanisms of individual differences in self-regulation during the first years of life. Self-regulation promotes a healthy development across the lifespan and functions as an important protective factor against the development of problematic behaviors. Understanding the predictors and underlying mechanisms of the development of self-regulation in early childhood is therefore of crucial importance. In line with biopsychosocial theory, a combination of neurobiological factors (frontal brain activity and functional brain networks) and psychosocial factors (parenting behaviors, risk factors, and center-based childcare attendance) were studied as potential predictors of individual differences in self-regulation. In addition, the relations of both parenting behaviors and center-based childcare attendance with the neurobiological mechanisms underlying child self-regulation were examined. By conducting five empirical studies, I addressed the three research aims of this dissertation: (1) examining the direct effect of children’s brain development on self-regulation, (2) examining the direct and indirect effects of children’s home environment on self-regulation, through children’s brain development, and (3) examining the direct effect of center-based childcare attendance on children’s brain development and self-regulation. The results of this dissertation demonstrate that, in line with biopsychosocial models, individual differences in self-regulation stem from a combination of neurobiological and psychosocial factors. Specifically, the results indicate that neurobiological factors (i.e., brain development) and psychosocial factors (i.e., parenting behaviors, prenatal risk factors, and center-based childcare) each uniquely contribute to the individual differences in self-regulation in the first years of life. At the same time, the results point towards a dynamic interplay between the