A McGill study that steered posture without telling anyone found upright sitters took more risks on a gambling task, and earned more doing it.

Generations of parents have told children to sit up straight. A new study from McGill University suggests the advice may matter for more than the spine. The posture people fall into without thinking, simply because of where a screen happens to sit, appears to shape how they feel and how much risk they are willing to take.

In the experiment, published in the British Journal of Psychology, volunteers who were quietly steered into sitting upright took more risks on a balloon-pumping game than volunteers steered into a hunch, and they tended to come out ahead. Neither group was told anything about posture.

The study was led by Soren Wainio-Theberge, a McGill graduate student who originated the idea, and Jorge Armony, a professor in the university’s Departments of Psychiatry and Psychology and the paper’s senior author. Armony stresses that the effects were modest and observed in a laboratory, but says they highlight how much the body can influence mood and behavior.

An idea with a troubled history

The notion that the body talks back to the mind is old. In 1884, William James argued that emotions are, in large part, the perception of bodily changes. Charles Darwin had earlier observed that simply acting out an emotion tends to stir it up. In 1988, psychologists Fritz Strack, Leonard Martin and Sabine Stepper famously had volunteers hold pens in their mouths in ways that forced or blocked a smile, reporting that the forced smilers found cartoons funnier. Stepper and Strack later extended the idea to posture, finding that people slumped in their chairs felt less pride after receiving good news.

The concept went mainstream in 2010, when Dana Carney, Amy Cuddy and Andy Yap reported in Psychological Science that holding expansive “power poses” for two minutes shifted hormone levels and made people more willing to gamble. Cuddy’s TED talk on the topic became one of the most-watched in the organization’s history.

Then the replications arrived. In 2015, a team led by economist Eva Ranehill tested about 200 people and found no effect of power posing on hormones or risk tolerance. Two years later, Joseph Simmons and Uri Simonsohn analyzed the published literature and concluded the evidence could not be distinguished from no effect at all. Carney herself publicly stated in 2016 that she no longer believed the effects were real.

Yet the story did not end there. Two 2022 meta-analyses, one led by Emma Elkjaer and another by Robert Körner, pooled dozens of studies and found that expansive and contractive postures do reliably nudge self-reported mood, with weaker and more contested support for effects on behavior. Both also flagged a nagging problem: effects tend to be larger in studies that lack a cover story. When someone is told to stand like a superhero, they know they are doing something, and they may give researchers the result they expect.

A tablet, a table and some tape

Wainio-Theberge and Armony set out to remove that awareness entirely. They recruited 198 participants, mostly young women from the McGill community, and told them they were testing a task being developed for mobile devices.

For half the group, the table was raised and the tablet mounted on a stand slightly above eye level, so the easiest way to see the screen was to sit tall. For the other half, the table was lowered to just above the knees and the tablet laid flat close to the body, inviting a hunch. In both cases the equipment was taped down so it could not be moved. Video software tracked each participant’s neck angle to measure how they actually sat.

Participants then played the Balloon Analogue Risk Task, a well-established measure in which each pump of a virtual balloon adds a dollar of play money to a pot. Cash out and the money is banked; pump once too often and the balloon pops, wiping out the pot.

Both groups grew bolder as the 30 rounds went on, but the upright group escalated faster, averaging about 36 pumps per cashed-out balloon compared with about 32 for the hunched group. Crucially, the upright sitters did not pop more balloons, and they tended to earn more overall.

Armony said that pattern suggests the upright participants “were not acting more impulsively but rather were engaging in more effective risk-taking.”

A comparison with more than 100 people who played the same game at an ordinary desk and monitor showed that the slouchers behaved much like this control group. The difference came mainly from the upright sitters, which runs against earlier meta-analyses that found posture effects concentrated in the slumped condition.

The mood findings were subtler. Being assigned to one table height or the other did not, by itself, produce a clear difference in mood. But the posture people actually adopted did matter: the straighter participants held their necks, the better their reported pride held up over the session. The authors argue that measuring real posture, rather than assuming everyone complied, gives researchers more statistical power to detect such effects.

Most participants said they had no idea their posture had been manipulated. When the analysis was restricted to the 72 people who reported no awareness whatsoever, the pattern held, though with less statistical certainty because of the smaller sample.

Why it matters, and what it doesn’t prove

If incidental posture shifts behavior, the implications reach well beyond the lab. Office ergonomics, standing desks, laptop heights and the hours many people now spend bent over phones all quietly shape how bodies are arranged. The authors write that such everyday features of work and home environments “may subtly influence their mood or behaviour.”

Armony is careful not to oversell. The results do not mean that changing posture can dramatically transform a person’s life, he said, but they raise interesting questions about how the spaces people work in may nudge them.

The researchers acknowledge real limitations. The sample was overwhelmingly young, female, university-educated and Canadian, so it is unclear how the findings would generalize to other populations and cultures. The hunched posture varied considerably, with some people dropping their heads and others leaning from the hips. And the study was not preregistered, a safeguard that has become standard in a field scarred by failed replications. The authors themselves caution that their work needs replication and further meta-analysis before anyone rearranges the office.

Still, by taking the instructions out of the experiment, the McGill team offers a cleaner test of an idea psychology has wrestled with for more than a century. The body, it seems, may be influencing the mind even when the mind isn’t paying attention.

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Endnotes

1. Wainio-Theberge, S., & Armony, J. (2026). Manipulating posture implicitly through environmental constraints influences mood and risk-taking behaviour. British Journal of Psychology, 117, 1618–1630. https://doi.org/10.1111/bjop.70083
2. McGill University. (2026, August 3). Posture can influence your mood and behavior, McGill study suggests [News release]. EurekAlert! https://www.eurekalert.org/news-releases/1138450
3. James, W. (1884). What is an emotion? Mind, 9(34), 188–205.
4. Darwin, C. (1872). The expression of the emotions in man and animals. John Murray. https://doi.org/10.1037/10001-000
5. Strack, F., Martin, L. L., & Stepper, S. (1988). Inhibiting and facilitating conditions of the human smile: A nonobtrusive test of the facial feedback hypothesis. Journal of Personality and Social Psychology, 54(5), 768–777. https://doi.org/10.1037/0022-3514.54.5.768
6. Stepper, S., & Strack, F. (1993). Proprioceptive determinants of emotional and nonemotional feelings. Journal of Personality and Social Psychology, 64(2), 211–220. https://doi.org/10.1037/0022-3514.64.2.211
7. Carney, D. R., Cuddy, A. J. C., & Yap, A. J. (2010). Power posing: Brief nonverbal displays affect neuroendocrine levels and risk tolerance. Psychological Science, 21(10), 1363–1368. https://doi.org/10.1177/0956797610383437
8. Ranehill, E., Dreber, A., Johannesson, M., Leiberg, S., Sul, S., & Weber, R. A. (2015). Assessing the robustness of power posing: No effect on hormones and risk tolerance in a large sample of men and women. Psychological Science, 26(5), 653–656. https://doi.org/10.1177/0956797614553946
9. Simmons, J. P., & Simonsohn, U. (2017). Power posing: P-curving the evidence. Psychological Science, 28(5), 687–693. https://doi.org/10.1177/0956797616658563
10. Carney, D. R. (2016). My position on “Power Poses.” Statement posted to faculty website, Haas School of Business, University of California, Berkeley.
11. Elkjaer, E., Mikkelsen, M., Michalak, J., Mennin, D., & O’Toole, M. (2022). Expansive and contractive postures and movement: A systematic review and meta-analysis of the effect of motor displays on affective and behavioral responses. Perspectives on Psychological Science, 17(1), 276–304. https://doi.org/10.1177/1745691620919358
12. Körner, R., Röseler, L., Schuetz, A., & Bushman, B. (2022). Dominance and prestige: Meta-analytic review of experimentally induced body position effects on behavioral, self-report, and physiological dependent variables. Psychological Bulletin, 148, 67–85. https://doi.org/10.1037/bul0000356
13. Lejuez, C. W., Read, J. P., Kahler, C. W., Richards, J. B., Ramsey, S. E., Stuart, G. L., Strong, D. R., & Brown, R. A. (2002). Evaluation of a behavioral measure of risk taking: The balloon analogue risk task (BART). Journal of Experimental Psychology: Applied, 8(2), 75–84.
14. Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world? Behavioral and Brain Sciences, 33(2–3), 61–83.