Habit Stacking

Where it comes from

In 1999, the psychologist Peter Gollwitzer described plans in the form when this happens, I will do that, and showed that they make a goal more likely to be carried out than a plain intention. He called them implementation intentions.

The Stanford researcher B. J. Fogg built his Tiny Habits method, from 2011, on a recipe in the same shape: after I do something I already do, I will do the new thing. James Clear popularized the pattern as habit stacking in his book Atomic Habits (2018).

Why it works

A habit you already have happens at a set time and place without a decision. Tying the new habit to it borrows that cue. After I pour my morning coffee, I will write three lines. After I sit down on the train, I will read one page.

A 2006 review of 94 tests found that plans like these have a medium to large effect. They still take time to become automatic. In a 2010 study, new daily habits took a median of 66 days to become automatic, with estimates from 18 to 254 days, so expect months rather than weeks.

How the module works

Two columns, After I and I will, once at the front of the book. Keep the new habit small enough that it is hard to skip, and make the anchor something you really do every day.