Me or you? Neural correlates of moral reasoning in everyday conflict situations in adolescents and adults.

Throughout adolescence, progress in the understanding of the moral domain as well as changes in moral behavior is observable. We tested 16 adolescents (14-16 years of age) and 16 healthy adults (22-31 years of age) on the developmental changes in everyday moral decision making using functional magnetic resonance imaging (fMRI). Using verbal stories describing everyday moral conflict situations, subjects had to decide between a moral standard or a personal desire. In the moral conflict situations, adolescents not only chose significantly more often the hedonistic alternative than adults, but they also reported higher certainty ratings. Contrasted with everyday social conflict situations that required a decision between a social-oriented behavior and a personal need, moral conflict situations induced an activity increase in frontal areas, the middle temporal gyrus, the thalamus, and the parahippocampal gyrus in adolescents compared to adults. Moreover, a closer look at the moral conflict situations revealed that adolescents showed more activity than adults in brain areas that are also centrally involved in theory of mind (ToM) during morally oriented decisions in contrast to personal-oriented decisions. This indicated that the development of moral reasoning may be strongly correlated with the development of ToM reasoning.