The authors respond to both the general and specific concerns raised in Fischer, Stein, and Heikkinen's commentary on their article (Steinberg, Cauffman, Woolard, Graham, & Banich), in which they drew on studies of adolescent development to justify the American Psychological Association's positions in two Supreme Court cases involving the construction of legal age boundaries. In response to Fischer et al.'s general concern that the construction of bright-line age boundaries is inconsistent with the fact that development is multifaceted, variable across individuals, and contextually conditioned, the authors argue that the only logical alternative suggested by that perspective is impractical and unhelpful in a legal context. In response to Fischer et al.'s specific concerns that their conclusion about the differential timetables of cognitive and psychosocial maturity is merely an artifact of the variables, measures, and methods they used, the authors argue that, unlike the alternatives suggested by Fischer et al., their choices are aligned with the specific capacities under consideration in the two cases. The authors reaffirm their position that there is considerable empirical evidence that adolescents demonstrate adult levels of cognitive capability several years before they evince adult levels of psychosocial maturity. (Contains 1 footnote.)