In 1968, Robert Zajonc published a monograph with an unglamorous title — “Attitudinal Effects of Mere Exposure” — and one of the most durable findings in social psychology. Show people a nonsense word, a Chinese character, a photograph of a stranger’s face, with no reward and no story attached, and simply showing it again makes them like it more. Repetition alone moves preference.
The finding has been replicated across decades, cultures, and stimuli. A 1989 meta-analysis by Robert Bornstein covering over 200 experiments confirmed the effect is real and reliable. It is part of why the songs on heavy rotation grow on you, why an unfamiliar city feels warmer the third week, why brands pay to be merely seen.
The detail most relevant here is the most encouraging one: Bornstein’s analysis found the effect was, if anything, stronger when the exposures were so brief or unattended that people did not consciously recognize the stimulus. Zajonc argued that liking does not need to pass through deliberate reasoning at all — “preferences need no inferences,” as his famous 1980 paper put it. Familiarity persuades below the level of argument, which means the words at the edge of your attention are working even when you are busy with something else.
It also works entirely without your supervision. You do not have to concentrate on the phrase, believe it hard, or catch every appearance. The mechanism asks one thing only — that the words keep showing up — and that is precisely the part a screen is better at than a person.
Some set of words is already enjoying heavy rotation in your head. The mere-exposure literature simply says that rotation has effects. Choosing the playlist yourself, and letting the phrases you actually want become the familiar ones, is the closest thing psychology offers to a free lunch — small, steady, and entirely on your side.