There is fairly widespread agreement that adolescents take more risks at least partly because they have an immature frontal cortex, the frontal cortex is the area of the brain that takes a second look at something and reasons about a particular behavior. One interpretation of all these findings is that in teens, parts of the brain involved in keeping emotional, impulsive responses in check are still reaching maturity. In addition, Dr. Jay Giedd at the National Institute of Mental Health in Bethesda, Md., together with colleagues at McGill University in Montreal hypothesizes that the growth in gray matter followed by the pruning of connections is a particularly important stage of brain development in which what teens do or do not do can
