Implementation intentions are said to transfer control over goal‐directed behavior to situational cues, thereby automating initiation of the behavior (Gollwitzer, 1999). Alternatively, implementation intentions may be effective because they create commitment to the intended behavior. In an empirical study, implementation intentions regarding a simple task (rating TV newscasts) varied in their specificity. In addition, explicit commitment to the task was manipulated, and chronic conscientiousness was assessed. Consistent with the commitment hypothesis, general and specific implementation intentions were equally effective in raising level of task performance, and they were no more effective than asking for an explicit commitment to carry out the task. Also, individuals high in conscientiousness were more likely than individuals low on this trait to enact their intentions.