Conditional or unconditional? The effects of implementation intentions on driver behavior.

Implementation intentions (if-then plans) exert conditional effects on behavior, meaning that their ability to change behavior is conditional upon encountering the critical situation specified in the if component of the plan. In the present study, we tested whether implementation intentions can exert unconditional effects on behavior. Consistent with the process of operant generalization, we hypothesized that implementation intentions would change behavior, not only in situations that are contextually identical to those specified in the if component but also in contextually similar situations. Implementation intentions were not expected to generate behavior-change in contextually different situations to those specified. Participants (N = 139) completed questionnaires measuring speeding behavior and motivation to speed. Experimental participants then specified implementation intentions to avoid speeding in critical situations that were contextually identical, similar, or different to those subsequently encountered on a driving simulator. Control participants received educational information about the risks of speeding. All participants then drove on a driving simulator. Consistent with the hypotheses participants in both the contextually identical and similar conditions exceeded the speed limit less frequently than did controls. There was no difference in speeding behavior between the contextually different and control conditions. Implications of the findings for behavior-change are discussed.