Affirmations: what the research actually found
There are two different things called affirmations. One has thirty years of experiments behind it. The other is the one on the poster.
6 min read · Published 7 September 2026
Straight to it
Self-affirmation, the version studied in psychology since the late 1980s, means reflecting in writing on a value that matters to you: family, honesty, being someone who shows up. It has been tested in hundreds of experiments and is associated with real effects: people become less defensive about threatening information, and short value-writing exercises have produced measurable academic gains in some school studies. The version sold on posters is different: repeating a statement you do not believe, in the present tense, at a mirror. That one has weaker support, and one well-known 2009 experiment found it backfired for people with low self-esteem, who felt worse after repeating 'I am a lovable person' than a control group who repeated nothing. The difference is not wording. It is that one asks what you value and the other asks you to assert something you know is not true yet.
Two practices, one word
The confusion is worth clearing up first, because the evidence for one gets used to sell the other.
Self-affirmation theory comes from Claude Steele's work in 1988. The claim is narrow: people are motivated to maintain a sense of themselves as good and capable, and when something threatens that sense, they get defensive. Reminding yourself of an unrelated value you hold restores enough self-integrity that you can look at the threatening thing without flinching. The standard exercise is not a mantra. It is a short piece of writing about why some value matters to you.
Positive affirmations in the self-help sense are declarative statements about yourself or your circumstances, repeated aloud, usually in the present tense, often about money or love or the body. The lineage runs back through New Thought in the nineteenth century and Émile Coué, whose patients repeated that every day, in every way, they were getting better and better.
Both are called affirmations. Only the first is what the studies mostly tested.
I do the first one, in a notebook, and I think the second is where a good practice goes wrong.
What the evidence supports
| Claim | Evidence | Where it stands |
|---|---|---|
| Writing about a core value reduces defensiveness about threatening information | Many randomised experiments since 1988; meta-analysed | Reasonably well supported |
| A brief value-writing exercise can narrow academic achievement gaps | School field experiments, some with multi-year follow-up | Supported in some settings; replication is mixed and effects vary by context |
| Self-affirmation reduces stress responses in the moment | Laboratory studies with physiological and self-report measures | Modest support, small effects |
| Repeating a positive self-statement raises self-esteem | Wood, Perunovic and Lee, 2009, and later work | Not supported for people with low self-esteem; it can make them feel worse |
| Repeating a statement about money or health changes the outcome | No credible experimental support | Not supported |
That table has a shape worth noticing. The claims that hold are about how you relate to a threat. The claims that do not hold are about changing the world by describing it differently.
The 2009 finding is the one most worth knowing, because it is the opposite of the promise. Participants with low self-esteem who repeated a flattering self-statement reported worse mood than those who did not. The proposed explanation is straightforward: a statement far outside what you believe about yourself invites your mind to argue back, and it argues with evidence.
Why the mirror version can backfire
Say something you half believe and you get a small correction. Say something you flatly disbelieve and you get a rebuttal, generated by you, with examples.
That is the mechanism people report: 'I am confident' produces a silent list of the times you were not. The statement was meant to install a belief and instead it ran an audit.
It also explains why the same phrase can help one person and sink another. Distance from what you currently believe is what matters, and that distance is different for everyone. A statement that is a modest stretch for one person is a lie to another.
Writing one that holds
What tends to work better
- Start from a value, not an outcome. 'I want to be someone who is steady with people' is a value. 'I am a millionaire' is an outcome, and it is not one you control.
- Write it down rather than reciting it. The studied version is a short piece of writing, a few sentences on why the value matters to you and a time you acted on it.
- Stay inside what you can believe today. 'I am learning to speak up' passes; 'I am fearless' invites the rebuttal.
- Make it about process. A statement about what you will do this week can be kept. A statement about what you are cannot be tested.
- Use it before the hard thing, not instead of it. The evidence is about facing threatening information without flinching, which means the affirmation is preparation, not a replacement.
- Let it be specific to you. The strength of the exercise comes from it being your value in your words, which is why a purchased list of a hundred affirmations does nothing much.
None of that requires believing anything about the universe rearranging itself. It is a way of steadying yourself before you walk into a room.
Where the practice sits alongside everything else here
Affirmations get bundled with manifesting, and they are not the same claim. Manifesting says a mental state changes external events. Self-affirmation says reflecting on your values changes how you handle a threat to your self-image. The second is a psychological claim about you, and it is the one with the evidence.
If you want the fuller version of the first argument, we have written it up separately in manifesting: what the research supports.
And the honest caveat that applies to this whole shelf: effect sizes in this literature are small, several headline results have had difficulty replicating, and a practice that helps you is not thereby proven to work in general. Both can be true.
Do affirmations actually work?
The version studied in psychology does something measurable: reflecting in writing on a value you hold reduces defensiveness about threatening information, and in some school experiments has improved outcomes. The version where you repeat a flattering statement at a mirror has much weaker support, and one 2009 experiment found people with low self-esteem felt worse afterwards.
How long does it take for affirmations to work?
There is no established timeline, and any source giving you a number of days is inventing it. The studied exercises are usually single sessions of ten to fifteen minutes of writing, measured immediately or over a school term. Nothing in the research supports a fixed period after which a repeated statement takes effect.
Should affirmations be in the present tense?
The self-help convention says yes, on the theory that the mind accepts a present-tense statement as fact. There is no good evidence for that. What matters more is whether you can believe the statement today. A future or process phrasing you accept beats a present-tense one you silently argue with.
Can affirmations make you feel worse?
Yes, and this is documented. In Wood, Perunovic and Lee's 2009 study, participants with low self-esteem who repeated a positive self-statement reported worse mood than a control group. The usual explanation is that a statement far from what you believe prompts you to recall counter-evidence.
Are affirmations religious?
Not inherently, though the practice has roots in New Thought, a nineteenth-century religious movement, and it echoes older devotional repetition in many faiths. People use affirmations inside a religious life and entirely outside one. The psychological research does not touch the question either way.
Santiago Garcias