How to Change: The Science of Getting from Where You Are to Where You Want to Be

by Katy Milkman

And fascinating research on rats has offered convergent evidence for this model of habit. It turns out that rats who have developed a heroin dependency react very differently if they receive an overdose of the drug in their familiar injection environment versus outside of it. If they’re injected with an overdose in an unfamiliar environment, they’re two times more likely to die. Why? When the rats are surrounded by their usual cues, their bodies react more habitually to the drug (the drug tolerance they’ve built up protects them), but in a foreign setting, their bodies underreact, which can be deadly. This research, though a bit macabre, vividly shows how a familiar environment affects the way mammals respond to familiar stimuli. We respond more habitually to drugs or eating popcorn or taking medication or exercising when we’re in familiar circumstances. Familiarity breeds habit.