Implementation intentions and goal achievement: A meta-analysis of effects and processes

Holding a strong goal intention ("I intend to reach Z!") does not guarantee goal achievement, because people may fail to deal effectively with self-regulatory problems during goal striving. This review analyzes whether realization of goal intentions is facilitated by forming an implementation intention that spells out the when, where, and how of goal striving in advance ("If situation Y is encountered, then I will initiate goal-directed behavior X!"). Findings from 94 independent tests showed that implementation intentions had a positive effect of medium-to-large magnitude (d = .65) on goal attainment. Implementation intentions were effective in promoting the initiation of goal striving, the shielding of ongoing goal pursuit from unwanted influences, disengagement from failing courses of action, and conservation of capability for future goal striving. There was also strong support for postulated component processes: Implementation intention formation both enhanced the accessibility of specified opportunities and automated respective goal-directed responses. Several directions for future research are outlined. © 2006 Elsevier Inc. All rights reserved.