Mere exposure
Repeated exposure to something increases liking for it, with no reason required.
Being shown a stimulus repeatedly raises preference for it, even when the person cannot recall seeing it. The effect is strongest for novel, low-meaning stimuli and at moderate numbers of repetitions. Past a point, repetition produces boredom and liking falls again.
How it shows up in software
Familiar interface conventions feel better because they are familiar, which is why a novel navigation pattern gets rated worse even when it tests faster. It also explains why a new feature's icon in the toolbar accrues clicks over weeks without any campaign, and why an unusual brand name stops sounding strange after a month of use.
Using it well
- Use platform conventions where the interaction carries no strategic value. Spend your novelty budget on the part of the product that is actually different.
- Introduce a big change gradually, with the new element visible before it becomes mandatory, rather than switching in one release.
- Keep a consistent visual signature across surfaces so exposure accumulates instead of resetting.
- Cap the repetition. An onboarding tip shown on every session crosses from familiar into irritating.
Where it turns manipulative
- Hammering an upsell into every screen so that repetition, not merit, produces the eventual click.
- Normalising an invasive prompt by repeating it until refusal feels like effort.
- Treating rising familiarity with a confusing pattern as evidence that the pattern is good.
Where you have seen it
Google Search
The results page layout has changed slowly and in small increments over many years rather than in wholesale redesigns.
Microsoft Office
New features are placed in the existing ribbon structure, so an unfamiliar capability arrives inside a familiar container.
What the research says
- Zajonc, 1968Well evidenced
Across word, character and face stimuli, rated liking rose with the number of prior presentations, without participants being told anything about them.
- Bornstein, 1989Well evidenced
A meta-analysis of over 200 experiments. The effect is robust, larger for brief and subliminal exposures, and follows an inverted U: too many repetitions reduce liking.
This is the important corrective. The effect is real and also self-limiting, and stimuli that are already meaningful show much smaller effects.
Grades are a judgement about the evidence, not about how useful the idea is. Plenty of contested effects are still worth knowing, as long as you do not cite them as settled.