Second, it is ironic that the remarkable increase in research on adolescent brain development during the past decade has outpaced research on the very psychological phenomena that this period of brain maturation presumably causes. One limitation of much extant psychological research is that few studies typically include an age range spanning preadolescence, adolescence, and early adulthood, likely because psychologists have been more interested in development during early and middle adolescence than during late adolescence or young adulthood. Consequently, there are many behavioral and self-report studies that compare children and adolescents, fewer that compare adolescents and adults, and almost none that compare children, adolescent, and adults all at once and allow for the detection of trends that may not be linear. This is especially problematic where reward-seeking and risk-taking are concerned, because, in light of research indicating the curvilinear nature of the developmental trajectory of dopaminergic receptor remodeling, there is reason to think that these behaviors increase until middle adolescence and then decline. In contrast, given what we know about maturation of the prefrontal cortex and its connections with other brain regions, the developmental course of cognitive control would be expected to increase linearly and into the decade of the 20s.
