Side-Effect effect without side effects: The pervasive impact of moral considerations on judgments of intentionality

Studying the folk concept of intentional action, Knobe (2003a) discovered a puzzling asymmetry: most people consider some bad side effects as intentional while they consider some good side effects as unintentional. In this study, we extend these findings with new experiments. The first experiment shows that the very same effect can be found in ascriptions of intentionality in the case of means for action. The second and third experiments show that means are nevertheless generally judged more intentional than side effects, and that people do take into account the structure of the action when ascribing intentionality. We then discuss a number of hypotheses that can account for these data, using reactions times from our first experiment.