The Best Laid Plans: Planning Skill Determines the Effectiveness of Action Plans and Implementation Intentions

Abstract

BACKGROUND: Theories of action control emphasise the importance of planning, but plans are not universally beneficial. PURPOSE: The present study investigates whether the effectiveness of plans depends upon the skill of the planner. METHODS: Study 1 prospectively predicted changes in unhealthy snacking behaviour over 1 week from intentions, action planning and performance on a standardised cognitive test of planning skill (n = 72). Study 2 experimentally randomised skilled and poor planners to receive (or not) a planning intervention before completing an online food diary (n = 144) RESULTS: Spontaneously generated action plans about snacking explained significantly more variance in subsequent snacking if produced by a skilled rather than a poor planner. The planning intervention (implementation intention) significantly improved goal attainment but only in poor planners. CONCLUSIONS: Plans are only as good as the people who make them. Poor planners' plans do not help achieve goals. Planning interventions can compensate for a lack of planning skill.