Abstract
The study of habit has long faced a trade-off between experimental control and ecological validity. We translated a core laboratory test of habit to daily life: whether people continue responding despite knowing it no longer produces its outcome. For one week, participants (N = 74) replaced a frequently used social media app with a nonfunctional decoy icon. The original app was either removed (Detox) or relocated (Switch). Taps on the decoy were recorded as action slips. Nearly all participants slipped (97%), with mean daily slips dropping from 9.76 on the first day to 1.08 on the last across both groups. Slips correlated with baseline app openings (rs = .61) and self-reported automaticity (rs = .40), but not with motivation to reduce usage, problematic use, perceived control, or well-being (|rs| ≤ .09). Decoy slips thus capture a key behavioural signature of habit and reveal how strong app-checking habits can be.