8 How to Maximize Implementation Intention Effects Peter M. Gollwitzer Frank Wieber Andrea L. Myers Sean M. McCrea How do people turn their intentions into behavior? This mirac1e is clarified in the present chapter by analyzing how if-then planning (i.e., implementation intentions; Gollwitzer, 1993, 1999) supports the trans- lation of intentions into actions. In addition, we will examine how if-then plans should be worded best to maximize their effectiveness. Subsequently, we will address the importance of the if-then format when wording implementation intentions by inspecting the extension of such plans into an if-then-why format, and by inspecting upward counter- factuals as an if-then format directed at past goal pursuits. IMPLEMENTATION INTENTIONS AND DIFFICULT GOAL STRIVING Whereas goal intentions merely specify desired end states ("I want to achieve goal X!"), implementation intentions in the format "If situation Y arises, then I will initiate behavior Z!" additionally specify when, where, and how a person intends to pursue a goal. Implementation intentions delegate control over the initiation of the intended goal-directed behavior to a specified opportunity by creating a strong link between a situation al cue and a goal-directed response. For example, a person who has the goal to become physically fit can form the implementation intention "If