Priming is the demonstrated effect where exposure to one concept — even briefly, even without conscious awareness — measurably shifts behavior or judgment related to that concept afterward. This isn't a subtle statistical footnote; well-documented priming studies show people physically walking slower after unscrambling sentences containing old-age-related words, without any of them ever being told the study was about aging at all.
The unsettling implication is that behavior can be nudged by inputs a person never consciously registers as relevant, which is precisely what makes priming effects useful to understand defensively: environments (a waiting room, a checkout aisle, a meeting room) contain far more subtle behavioral cues than most people account for when explaining their own choices.