Biological and environmental initial conditions shape the trajectories of cognitive and social‐emotional development across the first years of life

Human development is thought to evolve from the dynamic interchange of biological dispositions and environmental provisions; yet the effects of specific biological and environmental birth conditions on the trajectories of cognitive and social-emotional growth have rarely been studied. We observed 126 children at six time-points from birth to 5 years. Intelligence, maternal sensitivity, and child social engagement were repeatedly tested. Effects...