The past decade has seen an upsurge in public understanding of early brain development. News reports, statements by policymakers, and commercial marketing of products for infants and young children have all contributed to a widespread understanding of the explosive growth of the brain in the early years and that stimulation acts as a catalyst to brain growth. Beyond this, however, most people are unsure what to make of this new knowledge about brain development. This policy brief summarizes what is known about early neurobiological development and corrects some of the common misunderstandings and misrepresentations of the research.