Behavioural priming

Reading words about old age makes you walk more slowly; unrelated cues reshape behaviour.

What actually happened

The canonical elderly-priming study (Bargh, 1996) failed to replicate (Doyen et al., 2012). Kahneman himself wrote to the field warning of a coming 'train wreck' in this literature.

What to do instead

Ignore subtle-cue claims. The environmental effects that do hold up are blunt ones: distance, defaults, visibility, friction.

The laws that do this job properly

H·02Friction Beats WillpowerTwenty seconds of added effort kills a habit; twenty seconds removed creates one.proven
H·03Habits Live in Contexts, Not in YouAbout 43% of daily behaviour is repeated in the same context. Change the context and the habit has nothing to hold on to.proven
F·02The Phone Doesn't Have to BuzzA smartphone within reach reduces available working memory even when it is face-down, silent and switched off.solid
F·14Speech Is the Worst NoiseBackground speech you can make out words in degrades reading, writing and arithmetic. Meaningless noise at the same volume does not.solid

Every law on Useful Mind tells you how strong the evidence behind it is. The ones that failed are kept here rather than quietly deleted, because knowing which advice is wrong saves you as much as knowing which is right.

See the ones that held up