A teleological and behavioral view is presented of the concept of free will. Free will is not something people essentially have or do not have. Instead, the following question is asked: Why does society find it useful to label some actions free and some actions not free? It is argued that the function of such labels is to aid in assigning responsibility to people for their actions. Responsibility in turn is useful in assigning rewards and punishments. The sort of actions that are typically seen as free are the same as those seen as self-controlled. Such actions are responsive to environmental contingencies of relatively wide temporal extent. Copyright © 2007 John Wiley & Sons, Ltd.