The Science Behind Affirmations
Harnessing the Power of Words

Words of Affirmation

Affirmations are short positive statements people repeat to themselves: “I am capable”, “I am enough”. They are one of the most common self-help practices, and they sit next to a real body of psychology research, which is more specific and more mixed than the usual telling.

This page separates three things that often get blended together: the research on self-affirmation, the research on repeating positive statements about yourself, and beliefs such as the law of attraction, which is not a research finding at all.

Understanding Affirmations

The psychology behind affirmations has a name: self-affirmation theory. Claude Steele popularised it in the late 1980s; his main paper, “The psychology of self-affirmation: Sustaining the integrity of the self”, appeared in 1988, and it remains a well-studied theory in social psychology.

The theory says people are driven to protect their self-integrity: their sense of themselves as a good, moral person. When information threatens that picture (a health warning, criticism of their work), they tend to get defensive. If they first reflect on values that matter to them, they are less likely to experience distress and react defensively when confronted with that information.

Note what the theory is about: reflecting on values you already hold, usually by writing about them. That is a different thing from repeating a flattering sentence about yourself, and the evidence for the two is different too.

The Science of Affirmations: A Deeper Insight

Neuroplasticity

Neuroplasticity, the brain’s ability to reorganise and rewire its connections, is real. It is often invoked to say that reciting affirmations rewires the brain in a chosen direction. The studies on this page measure mood, defensiveness and behaviour, not that kind of brain change. The one brain-imaging study among them, by Cascio and colleagues (2016), looked at values affirmation: people who were affirmed showed more activity in brain regions linked to self-related processing and reward while reflecting on future-oriented core values.

The Role of the Reticular Activating System (RAS)

The reticular activating system is a set of connected nuclei in the brainstem that regulates wakefulness and the transitions between sleep and waking. That is well established.

The popular self-help version, in which the RAS works as a filter that lets in only information matching your goals, goes well beyond that description.

What is well described is selective attention. Once something is on your mind, you notice it far more often, even if it is not happening more often. The linguist Arnold Zwicky called one form of this the frequency illusion in 2005; it is also known as the Baader-Meinhof phenomenon: the car you are thinking of buying suddenly seems to be everywhere. Holding a goal in mind can make relevant opportunities easier to notice; it does not make them more numerous.

Affirmations and the Law of Attraction

The law of attraction is the New Thought belief that positive or negative thoughts bring positive or negative experiences into a person’s life. It is a belief, not a finding: there is no empirical scientific evidence supporting it. Affirmations and the law of attraction are often presented together, which can lend the second the credibility of the first. They are not the same kind of claim. There is more on this further down.

What the research found

Self-affirmation has a measurable effect, and it is small. A 2015 meta-analysis by Epton and colleagues pooled 144 experimental tests of self-affirmation alongside health-risk information. It found “small but reliable positive effects” on accepting the message, on intentions to change and on later behaviour. The authors describe the effects as small in size, and comparable to other health-behaviour interventions.

It does not always hold up outside the lab. Values-affirmation writing exercises have also been tried in schools. In a large replication by Hanselman and colleagues (2017), in a setting where an earlier large field experiment had found benefits, the same procedure showed no evidence of effects, and the estimates were precise enough to rule out benefits larger than an effect size of 0.10.

How it is done may matter. In a 2021 study of 1,056 people by Iles and colleagues, affirmations written as essays worked better than questionnaire-style versions for changing intentions to drink less, and the authors concluded that essays with an explicit focus on values were “most potent”.

Repeating a positive statement about yourself is a separate question, and the evidence is disputed. In 2009, Wood, Perunovic and Lee (Psychological Science) had people repeat “I’m a lovable person”. Participants with low self-esteem who repeated it felt worse than those who did not. Participants with high self-esteem felt better, “but to a limited degree”. The authors concluded that repeating positive self-statements may benefit certain people “but backfire for the very people who ‘need’ them the most”.

In 2020, Flynn and Bordieri (Journal of Contextual Behavioral Science) ran two replications, with about 225 and 237 participants. Neither found the effect: there were no differences between conditions on mood or state self-esteem, and in the first study trait self-esteem did not change the result. The second study compared positive affirmations with writing about values, and found no difference between them either. So the backfire finding is not settled. Neither set of studies shows a reliable lift in mood from repeating a positive statement.

The Secret, the law of attraction, and the law of assumption

These come up often alongside affirmations, so here is where they stand.

Where it comes from. The Secret by Rhonda Byrne was released as a film in March 2006 and as a book later the same year. Byrne’s official site reports sales of over 30 million copies. Byrne cites Wallace Wattles’ The Science of Getting Rich (1910) as her inspiration, and the idea belongs to the New Thought movement, which coalesced in the United States in the 19th century. Neville Goddard (1905–1972) taught a related method he called the law of assumption.

How the two differ.

	Law of attraction	Law of assumption
Core claim	Positive or negative thoughts bring positive or negative experiences	“Assume the feeling of the wish fulfilled”
How it is said to work	Thoughts send out “vibrations” that something in the universe answers; like attracts like	Mentally and emotionally inhabit the state of already possessing what is desired
Associated with	Rhonda Byrne, The Secret	Neville Goddard

What the evidence says. Neither has scientific support. Reviewing The Secret for Live Science in 2009, the writer Benjamin Radford concluded that its law of attraction “has nothing to do with science”. When these methods seem to work, there is a simpler explanation, in our reading: deciding clearly what you want changes what you notice, what you try and what you say yes to.

The criticism that matters. Writing for the Committee for Skeptical Inquiry, Mary Carmichael and Ben Radford said the premise of The Secret contains “an ugly flipside: if you have an accident or disease, it’s your fault”. That conclusion is built into the idea, and any version worth keeping has to drop it.

What is left is planning: decide what you want, picture it clearly enough to recognise a chance when it comes, and then do the work.

Auto-suggestion: where the idea came from

Auto-suggestion is older than Napoleon Hill: Herbert Parkyn taught it at his Chicago School of Psychology from 1896 and in a 1906 book, and Émile Coué popularised it in the 1920s. Napoleon Hill’s Think and Grow Rich (1937) made it the book’s third “step toward riches”. Hill defined it as “self-suggestion”, and he was clear that “plain, unemotional words do not influence the subconscious mind”: the words had to be “well emotionalized with BELIEF”. Earlier in the book he tells readers to read their written statement of desire aloud twice daily.

Two notes on Hill as a source. Newspapers of his day, quoted by the journalist Matt Novak, report warrants for his arrest in Alabama in 1908, when a postal mail-fraud investigation was also under way, and in Illinois in 1918, for breaching the state’s Blue Sky Law on selling stock. In October 1919 the Federal Trade Commission charged him with fraudulent advertising. His story that Andrew Carnegie set him the task of studying successful people appeared only after Carnegie died in 1919. And his central promise, that belief plus repetition produces wealth, is the part the evidence above does not support.

Affirmations worth using

If you want to try affirmations, here are some ways to do it. The first is closest to what the studies tested; the rest are our own suggestions:

• Write about a value. The self-affirmation research is mostly about reflecting on values that matter to you, often in a short piece of writing, rather than repeating a sentence about yourself.
• Choose something you can nearly believe. “I am handling this” is easier to accept than “I am unstoppable”.
• Prefer process to identity. “I prepare for difficult conversations” is something you can check and make true; “I am confident” is not.
• Pair it with an action. An affirmation with nothing behind it is a wish; attached to a habit, it becomes a plan.
• Notice how it lands. If a phrase leaves you feeling worse, that is worth paying attention to, whatever the studies say on average.

Some examples in that spirit:

• I am doing what today asks of me.
• Mistakes are information. I use them and move on.
• I am allowed to be imperfect and still be worth something.
• Change is normal. I adapt.
• I am making steady progress, even on days I cannot see it.

Persistent low mood or low self-worth is worth raising with a doctor or a qualified counsellor. A list of phrases is not treatment.

Positive thinking, in proportion

What holds up. Optimism, in the research sense, means holding generally favourable expectations for the future. A 2010 review by Carver, Scheier and Segerstrom links it to better well-being in hard times, to engagement coping (dealing with a problem) rather than avoidance, to more persistence in education, and to better relationships. The review also notes that there are instances where optimism brings no advantage, or a disadvantage, though it describes them as relatively rare.

Health. A 2019 meta-analysis by Rozanski and colleagues (JAMA Network Open), covering 15 studies and 229,391 participants, found optimism associated with a lower risk of cardiovascular events and of death from any cause. These are observational studies: they show an association, not that thinking positively prevents or treats illness. The authors themselves call for studies of the mechanisms and of whether interventions help.

The version we find workable: accurate about the situation, confident about responding to it. Notice what is going well, take a setback seriously enough to learn from it, and let a bad day be a bad day.

What you can do with this

• Tell the three ideas apart. Self-affirmation (reflecting on your values) has research behind it, with small effects that do not always replicate. Repeating positive statements about yourself has mixed evidence. The law of attraction has none.
• Try the version closest to the studies. A few minutes writing about something that matters to you is closer to what the self-affirmation studies tested than repeating a slogan, though one 2020 comparison found no difference between the two.
• Treat attention as the useful part. Holding a goal in mind helps you notice chances; acting on them is what changes things.
• Be wary of any method that blames you for bad luck or illness. That part is built into the law of attraction, and it is not supported by anything.

Sources

• Wikipedia, “Self-affirmation” (the theory; Steele, 1988).
• Epton, T., Harris, P. R., Kane, R., van Koningsbruggen, G. M. and Sheeran, P. (2015), “The impact of self-affirmation on health-behavior change: a meta-analysis”, Health Psychology 34(3), 187–196 (PubMed 25133846).
• Hanselman, P., Rozek, C. S., Grigg, J. and Borman, G. D. (2017), “New Evidence on Self-Affirmation Effects and Theorized Sources of Heterogeneity from Large-Scale Replications”, Journal of Educational Psychology (PubMed 28450753).
• Iles, I. A., Gillman, A. S., Ferrer, R. A. and Klein, W. M. P. (2021), “Self-affirmation inductions to reduce defensive processing of threatening health risk information”, Psychology & Health.
• Cascio, C. N. and colleagues (2016), “Self-affirmation activates brain systems associated with self-related processing and reward and is reinforced by future orientation”, Social Cognitive and Affective Neuroscience 11(4), 621–629 (PubMed 26541373).
• Wood, J. V., Perunovic, W. Q. E. and Lee, J. W. (2009), “Positive self-statements: power for some, peril for others”, Psychological Science 20(7), 860–866 (PubMed 19493324).
• Flynn, M. K. and Bordieri, M. J. (2020), “On the failure to replicate past findings regarding positive affirmations and self-esteem”, Journal of Contextual Behavioral Science 16, 49–61.
• Carver, C. S., Scheier, M. F. and Segerstrom, S. C. (2010), “Optimism”, Clinical Psychology Review 30(7), 879–889 (PubMed 20170998).
• Rozanski, A., Bavishi, C., Kubzansky, L. D. and Cohen, R. (2019), “Association of Optimism With Cardiovascular Events and All-Cause Mortality”, JAMA Network Open 2(9), e1912200 (doi).
• Wikipedia, “Autosuggestion” (Herbert Parkyn, citing his own Auto-Suggestion: What It Is and How to Use It, 1906) and “Émile Coué” (citing The Oxford Companion to the Mind, 1987).
• Wikipedia, “Neuroplasticity”, “Reticular formation”, “Frequency illusion”, “Law of attraction (New Thought)”, “The Secret (Byrne book)”, “The Secret (2006 film)”, “New Thought”, “Neville Goddard”, “Napoleon Hill” and “Think and Grow Rich”.
• Napoleon Hill, Think and Grow Rich (1937), contents and chapter 4, “Auto-Suggestion”, at sacred-texts.com.
• Matt Novak, “The Untold Story of Napoleon Hill, the Greatest Self-Help Scammer of All Time”, Gizmodo (6 December 2016), quoting the Pensacola Journal (1908) and the Chicago Daily Tribune (1918).
• Benjamin Radford, “The Pseudoscience of ‘The Secret’”, Live Science (3 February 2009); Mary Carmichael and Benjamin Radford, “Secrets and Lies”, Skeptical Inquirer (29 March 2007).
• Arnold Zwicky, “Just between Dr. Language and I”, Language Log (7 August 2005) (the frequency illusion).

Checked September 2026. The research findings rest on the papers’ own abstracts (PubMed, and the publisher’s page for Flynn and Bordieri); the history of the law of attraction, The Secret and Goddard follows the Wikipedia articles listed, used only where they give a citation for the sentence; the record on Hill follows Novak’s reporting; Hill’s words are from his own chapter on auto-suggestion. Where studies disagree, as on repeating positive self-statements, the page gives both.