The idea that you can change how you feel by changing how you sit or stand is one of the most appealing claims in popular psychology, and also one of the most misunderstood. It became famous, then it became a cautionary tale about science that overreached, and somewhere in the wreckage a smaller and more honest truth survived. That truth is roughly the one in the title: adjusting your posture can genuinely shift how confident you feel in a given moment, without doing anything as dramatic as rewiring your hormones or altering the kind of person you are. Untangling what the evidence actually supports from what it does not is worth doing carefully, because both the hype and the backlash got part of it wrong.
The claim that overreached
The story starts in 2010, with a study by Dana Carney, Amy Cuddy and Andy Yap that became one of the most cited and most watched pieces of psychology of its era, largely through a hugely popular TED talk. The claim was bold. Holding an expansive, powerful posture for two minutes, hands on hips, feet apart, taking up space, supposedly did far more than change your mood. It was said to raise testosterone, lower the stress hormone cortisol, and make people more willing to take risks. Posture, in this telling, reached down into the endocrine system and remade your body chemistry, not just your feelings.
It was a thrilling idea, and easy to sell: two minutes in a bathroom stall before an interview could biologically transform you. The problem is that the strongest and most memorable parts of the claim did not hold up.
What the replications actually found
When other researchers tried to reproduce the results, the grand version fell apart. In a larger and more tightly controlled study, Eva Ranehill and colleagues ran the experiment with 200 participants, and found that expansive postures produced no detectable effect on hormones and no effect on actual risk-taking behavior, while a later analysis of the wider literature concluded that the behavioral and physiological claims should be treated as hypotheses lacking empirical support. The testosterone, the cortisol, the risk-taking: none of it reliably reappeared.
The most striking part came from inside the original team. In 2016 Dana Carney, the lead author of the 2010 paper, published a statement saying she no longer believed the effect was real, writing plainly that she did not think power pose effects existed and that the evidence against them was, in her words, undeniable. It is rare and admirable for a scientist to disown her own famous finding, and it settled the matter for the dramatic claims. If you were told that standing like a superhero would spike your testosterone, that part is not supported.
The part that quietly held up
Here is the twist that the backlash often missed, though. Even the skeptical replication found one thing consistently. People who adopted an expansive posture reliably reported feeling more powerful and more confident afterward. The manipulation worked on the mind even when it did nothing to the bloodstream. The self-reported, in-the-moment feeling of confidence was real and repeatable; it was only the physiological and behavioral machinery beneath it that turned out to be imaginary.
And this modest effect shows up beyond the power-pose experiments. In a separate randomized study, Shwetha Nair and colleagues had people sit either slumped or upright while facing a stressful speaking task. The upright group reported higher self-esteem, better mood, and less fear under stress than the slumped group, and used more positive and less self-focused language, suggesting that sitting upright may be a simple way to buffer the mind against a stressful moment. This is the sturdier, less glamorous finding: posture nudges how you feel and how you carry yourself through a difficult situation.
Why it can lift confidence without changing who you are
This is exactly where the title’s careful phrasing earns its keep. What posture appears to influence is a state, a temporary condition of how confident or at ease you feel right now, not a trait, the stable personality that persists across your whole life. Straightening up before you walk into a room can help you feel more composed in that room. It does not convert a shy person into an extrovert, or a cautious one into a daredevil, and nothing in the credible evidence suggests it should.
The useful way to think of it is as accessing what is already there rather than installing something new. A more open posture may help you feel a little less shrunken and a little more present in a high-pressure moment, letting you draw on your own existing resources instead of collapsing inward. Your personality stays exactly what it was. What shifts is your momentary relationship to it.
The honest limits
A few cautions keep this in proportion. The surviving effects are small, they rest largely on how people say they feel rather than on hard behavioral outcomes, and self-reports can be swayed by knowing what a study is testing. This is a nudge, not a transformation, and it is no substitute for actual preparation; standing tall before an interview you have not prepared for will not save you. The effect is also likely to vary from person to person, and for some it may do very little at all.
None of that makes it worthless. A cheap, momentary boost to how confident you feel, available any time you remember to uncross your arms and lift your chest, is a perfectly real and useful thing. It simply is not magic, and it was the overselling, not the underlying grain of truth, that caused the trouble.
Where it leaves us
So the accurate version is narrower than the viral one and more reliable for it. Adjusting your posture will not flood you with hormones or rebuild your character, and anyone still promising that is selling the debunked version. But sitting or standing a little taller can genuinely help you feel steadier and more confident in a hard moment, working on your state rather than your soul. Keep the modest, evidence-backed claim and drop the miraculous one, and you are left with something small, honest, and quietly worth doing.