Recent advances in neuroscience show clearly how experience can change brain neurochemicals, and how this in turn affects the way the brain functions. As a result, early negative events actually get built into the growing brain's neurochemistry, altering the brain's architecture. Research is continuing to investigate how children with genetic vulnerabilities, such as autism, schizophrenia, and anxiety and attention disorders, are affected by early experiences, and the relationship between brain chemistry the expression of these genes. The science is clear as it relates to public policies: from a neuroscience perspective, it is far better to prioritize early supports that promote positive social and emotional development in children than to wait until the problems occur and try to fix them.