The purpose of the study was to explore to what extent previously acquired moral concepts rather than the learning of new behavior affect the delinquents' level of intentionality (i.e., the developmentally more mature judgment of a deed in terms of intent rather than consequent material damages). The sample population was administered a 12-item set of intentionality pairs, in which one story describes how a child's helpful or selflessly motivated act results in considerable material damage, while another child's maliciously motivated act results in only minor material damage. The subjects were asked which child in each story pair was 'naughtier.' After this initial testing, the adolescents were randomly assigned to an experimental group and a control group. While the control group took a second 12-item set of intentionality pairs under the same testing circumstances, the experimental group was asked to match the responses of a group of high school teachers who had previously taken the test. For each correct (matching) answer, they were promised a small sum of money. The statistical analysis of results indicated that the experimental group averaged a 20 percent overall increase in the number of intentional choices, from their pretest mean of 40 percent to a posttest mean of 60 percent, while the scores of the control group remained virtually unchanged. The evidence indicates that, given appropriate incentive, adolescents will apply previously learned moral responses in exercising mature moral judgment. The article also considers possible rival interpretations of the results. Nine references, footnotes and statistical data are included.