Priming is when encountering one thing, like a word, picture or sound, changes how you respond to something related shortly afterward, usually without your noticing. Some kinds of priming, like recognizing the word “butter” a little faster after seeing “bread,” are well established. Many famous claims that subtle cues change complex behavior, like walking more slowly after seeing words linked to old age, have not held up.
What is priming in psychology?
A priming experiment has two parts: the prime, which you see or hear first, and the target, which you respond to next. If the prime changes how quickly or accurately you respond to the target, that’s priming. Psychologists describe it as a form of memory that works without awareness: a trace of what you just processed makes related things easier to process next (Tulving & Schacter, 1990).
You can’t usually feel priming happen. It shows up in measurements, such as how long it takes someone to recognize a word, rather than in anything a person would notice about themselves.
The main types of priming
- Semantic priming. A word speeds up recognition of words related in meaning. In the classic experiments, people were faster to decide that two strings of letters were both real words when the words were commonly associated (think “bread” and “butter”) than when they weren’t (Meyer & Schvaneveldt, 1971).
- Repetition priming. Seeing a word or object once makes it easier to identify again later, even if you don’t consciously remember the first time (Tulving & Schacter, 1990).
- Behavioral or social priming. The claim that brief, incidental exposure to an idea, such as words about old age, money or intelligence, changes how people act afterward. This is the type that ran into trouble.
Semantic priming: the part that holds up
Semantic priming has been tested for decades in labs around the world. A meta-analysis of 26 studies concluded that it happens automatically, even between words that share meaning without usually appearing together, such as synonyms and opposites (Lucas, 2000). The Semantic Priming Project, the largest behavioral database on the effect, recorded responses to 1,661 target words from 768 people at four universities (Hutchison et al., 2013).
Two things are worth knowing about it. First, the effects are small in everyday terms: they are differences in how fast people respond, measured in fractions of a second. Second, they are narrow. One research team described the usual pattern in word-priming experiments this way: priming is “very narrow in its generalization,” and unconscious influences, “if they occur at all, are extremely short-lived” (Shanks et al., 2013).
So semantic priming tells us something real about how memory is organized. It does not tell us that a word you glimpse can change what you do an hour later.
Behavioral priming: the famous studies that didn’t replicate
In 1996, a widely cited paper reported that people primed with words about rudeness interrupted an experimenter more quickly and more often than people primed with politeness, and that people exposed to the stereotype of old age walked more slowly down the hallway as they left the lab (Bargh, Chen & Burrows, 1996). The walking study helped define a whole area of research on unconscious influences on behavior.
In 2012, a team tried to repeat it with automated timing and a larger sample, and found no effect. They then ran a second experiment in which they told some experimenters to expect slower walking and others to expect the opposite. People walked more slowly only when the experimenters expected them to, and interviews afterward suggested some participants had noticed the primes. The authors concluded that the walking effect involves mechanisms different from those usually assumed, including the experimenters’ own expectations (Doyen et al., 2012).
Other well-known findings fared no better:
- Priming intelligence. Studies had suggested that thinking about professors could improve scores on a general-knowledge quiz. Nine experiments with 475 people using the same procedures and variations of them found no effect (Shanks et al., 2013).
- Flags and money. A project that repeated 13 effects across 36 samples and 6,344 people found that 10 replicated consistently. Two priming effects did not: seeing a flag shifting people’s political views, and reminders of money shifting attitudes about the social system (Klein et al., 2014).
- Money priming overall. A meta-analysis of 246 money-priming experiments found an average effect, but also signs of publication bias (studies with positive results being more likely to get published), which makes an average look bigger than it really is. The authors called for large, preregistered studies to settle it (Lodder et al., 2019).
Why did so many of these findings fall apart? The cited studies point to a few reasons. Experimenters’ expectations can leak into results, as the walking study showed (Doyen et al., 2012). Publication bias can make an effect look larger than it is (Lodder et al., 2019). And when many labs test the same effect under one shared plan, as in the 36-sample project above, findings that looked solid in a single lab can fail to hold up, even while most other effects in the same project replicate (Klein et al., 2014).
A 2019 feature in Nature described social priming as a promising field that struggled after researchers couldn’t repeat key findings, and that is now trying to work out what’s worth saving (Chivers, 2019).
Is behavioral priming dead? Not quite
To be fair to the field, some behavioral priming effects do appear. A meta-analysis of 133 studies found a small average effect of incidentally presented words on behavior, stronger when the idea was linked to something people valued (Weingarten et al., 2016). And one team ran six replications with 988 people and found that primes consistently nudged decisions in a simple betting game when the choice was uncertain, even when people were warned to ignore them (Payne, Brown-Iannuzzi & Loersch, 2016).
The fairest summary: primes can nudge quick, uncertain choices in some lab tasks. The evidence is much weaker for the striking claims that a passing cue reshapes complex behavior, like how fast you walk, how well you do on a test, or what you think about politics.
What priming does and doesn’t mean for affirmations
Affirmations are sometimes sold as a way to “prime your mind” or “program your subconscious.” Here’s what the research supports.
It doesn’t support the idea that words quietly reprogram you. Semantic priming is real but brief and narrow. The dramatic behavior-change claims are the part that failed to replicate.
Subliminal affirmations have been tested directly, and they failed. In double-blind studies, 237 people used subliminal self-help tapes, sold to improve memory or self-esteem, for a month as the makers recommended. Some got tapes whose labels didn’t match the hidden content. Neither kind of tape had its claimed effect. Everyone improved a little, whatever tape they had (a placebo effect), and more than a third believed they had improved in whatever area the label named (Greenwald et al., 1991).
What does carry over is planning. Deciding in advance exactly when and how you’ll act (“When I walk into the meeting, I’ll breathe out and say my first point slowly”) is a well-supported way to follow through. Across 94 tests, these if-then plans helped people reach their goals, partly because they made the planned moment easier to notice and the response more automatic (Gollwitzer & Sheeran, 2006). That is a deliberate version of what priming promised to do by stealth.
So use affirmations on purpose. Say or listen to them when you can pay attention, make them believable, and tie them to the moments where you’ll need them. A line you understand and chose is doing something very different from a word flashed past you. If you want lines written that way, start with our daily affirmations.
The short version
- Priming means something you just encountered changes how you process something related soon after, usually without your noticing.
- Semantic and repetition priming are well established, but the effects are small and narrow, and semantic priming is brief.
- Many famous behavioral priming findings, including the elderly-walking study, intelligence priming and money priming, failed to replicate or look inflated. Some small effects on quick, uncertain choices do hold up.
- There’s no good evidence that affirmations work through hidden priming, and subliminal self-help tapes didn’t do what they claimed. If affirmations help, it’s more likely through what you choose to focus on, value and plan.