The core idea
If a behavior requires daily willpower, it’s not a habit yet. Design the environment so the default choice is the healthy one.
Implementation intentions turn goals (“I want to exercise”) into a specific trigger-response rule:
If it is 7:30am and I finish coffee, then I put on shoes and walk for 10 minutes.
Meta-analytic evidence suggests implementation intentions have a medium-to-large effect on goal attainment across many contexts.[1]
When you repeatedly “fail”, it’s usually one of these:
The Fogg Behavior Model summarizes this as Motivation × Ability + Prompt.[2]
In a real-world habit formation study (daily repetition in the same context), automaticity increased with an asymptotic curve — but timelines varied widely (roughly weeks to many months).[3]
Practical implication: aim for consistency, not perfection. Missing one opportunity did not appear to “reset” the process in that study.[3:1]
| Question | Example |
|---|---|
| What’s the smallest version? | “2‑minute outdoor light” instead of “perfect morning routine” |
| What’s the trigger? | “After bathroom” |
| What’s the prompt? | Shoes by the door |
| What’s the friction? | Moving the phone charger out of bedroom |
| What’s the reward? | A coffee ritual after the walk |
Gollwitzer PM, Sheeran P. Implementation intentions and goal achievement: A meta-analysis of effects and processes. Adv Exp Soc Psychol. 2006;38:69–119. https://doi.org/10.1016/S0065-2601(06)38002-1 ↩︎
Fogg Behavior Model (overview). https://www.behaviormodel.org/ ↩︎
Lally P, van Jaarsveld CHM, Potts HWW, Wardle J. How are habits formed: Modelling habit formation in the real world. Eur J Soc Psychol. 2010;40(6):998–1009. https://doi.org/10.1002/ejsp.674 ↩︎ ↩︎