Gollwitzer & Sheeran (2006): Implementation Intentions Meta-Analysis
Gollwitzer and Sheeran pooled 94 independent studies of implementation intentions, plans of the form 'if situation X arises, then I will do Y', and found they improved goal attainment with a medium-to-large effect (d = .65) beyond simply having the goal. The plans work by handing the start decision to the environment: the specified cue triggers the action, so initiation no longer depends on in-the-moment motivation. It is the strongest evidence base behind any technique on this site.
| Citation | Gollwitzer, P. M., & Sheeran, P. (2006). Implementation intentions and goal achievement: A meta-analysis of effects and processes. Advances in Experimental Social Psychology, 38, 69–119. |
|---|---|
| Study type | Meta-analysis of 94 independent tests, over 8,000 participants |
| Key finding | Implementation intentions improved goal attainment, d = .65, over goal intentions alone |
| Mechanism | Cue detection and automated action initiation; effects strongest where people usually fail to start |
What the study found
Across domains from exercise and diet to studying, screening attendance and interpersonal goals, participants who formed a specific if-then plan achieved their goals substantially more often than participants with equally strong goals but no plan. The pooled effect of d = .65 is unusually large for such a cheap intervention. Process evidence showed the mechanism: the plan links a concrete cue to a concrete response, so when the cue appears, action starts with little deliberation, exactly the step where procrastinators stall.
Why it matters
Most goal advice tries to raise motivation; implementation intentions sidestep it. For procrastination this is the crucial move, because the gap is rarely in wanting the outcome, it is in initiating at a specific moment. 'I will write the report' loses to any distraction; 'when I sit down with coffee at 9am, I will open the report file' has a trigger the environment supplies. The technique costs one sentence and is among the best-replicated effects in applied psychology.
Caveats
Effect sizes vary widely by domain and are smaller for difficult, long-term goals than for one-off actions, and many included studies used student samples with short follow-ups. Meta-analyses of this era predate modern publication-bias tools, and later work suggests the average effect may be somewhat inflated, though the core effect has replicated repeatedly. Plans also fail when the underlying goal commitment is weak: an if-then plan for a goal you do not actually hold does nothing.
Peer-reviewed meta-analysis in Advances in Experimental Social Psychology, the standard citation for implementation intention effects.
Related
Implementation Intentions (how to use them)Lally et al. (2010) on habit formation
Frequently asked questions
Do implementation intentions work for procrastination?
The meta-analysis covers goal attainment broadly, with a d = .65 advantage for planners, and the mechanism targets task initiation, which is procrastination's failure point. Later studies applying if-then plans directly to procrastinated tasks, including bedtime, support the transfer.
What is an example of an implementation intention?
The format is 'if X, then I will Y' with both halves concrete: 'when I close my laptop after my last meeting, I will put my running shoes on', or 'if it is 9pm, then I will start charging my phone in the kitchen'. Vague versions like 'I will exercise more' are goal intentions, not implementation intentions.