The frontal lobe is one of the last areas of the brain to reach full maturity. In fact the frontal lobe does not complete synaptic formation and myelination until the mid-twenties. In this regard, ontogeny does recapitulate phylogeny; in both development and evolution the frontal lobe is a late comer. This is entirely consistent with our observations about the intellectual abilities and social judgment of children and adolescents. While many brain functions, such as physical coordination and language abilities, are fully mature by adolescence, social judgment and abstract thought take considerably longer to mature.