Keep the cue and reward, swap the routine

Duhigg’s “golden rule”: change a habit by inserting a new routine between the same cue and reward.

Why it works

Cues and rewards are deeply wired and hard to delete, but the routine in the middle is the most editable link in the chain. Leaving the cue and reward intact while substituting a new routine lets the loop keep firing on its existing trigger and still pay out — so you redirect the habit rather than fighting to extinguish it, which is far harder.

How to do it

1. Once you know the cue and the real reward, choose a new routine that still delivers that reward.
2. Write a plan: when [cue] occurs, I will [new routine] to get [reward].
3. Run the new routine on the same cue every time until it becomes the default response.

Evidence

Consistent with extinction/substitution findings: old cue-response associations are rarely erased but can be overlaid by stronger new ones. Duhigg presents the "golden rule" as a synthesized framework drawn from clinical and research examples rather than a single controlled trial of the rule. (mechanistic)

Old habits can re-emerge under stress because the original loop is suppressed, not deleted — substitution manages a habit, it does not guarantee erasure.

Common mistake

Trying to remove the cue or white-knuckle the reward away instead of substituting the routine, which leaves the craving unmet and the old behavior ready to snap back.