When tennis legend John McEnroe bellowed “You cannot be serious!” at Wimbledon in 1981, he wasn’t just venting frustration—he may have been tapping into something primal that helped fuel his championship run. Samuel L. Jackson built an entire acting persona around his explosive vocabulary, while Gordon Ramsay once set a television record by cursing 243 times in a single episode of Kitchen Nightmares. Joe Pesci’s profanity-laced performances in films like Goodfellas have become the stuff of cinematic legend.

But beyond the entertainment value, new research suggests these famously foul-mouthed figures might be onto something significant. A study published in the American Psychological Association’s flagship journal, American Psychologist, has revealed the psychological mechanism behind why swearing actually improves physical performance—and the findings have implications for anyone looking to push their limits.

The research, conducted by Richard Stephens of Keele University in the United Kingdom and his collaborators, builds on more than a decade of work demonstrating that cursing produces measurable physical benefits. Previous studies had already established that people who swear can keep their hands submerged in ice water longer, produce more power during intense exercise, and maintain stronger grip strength. What remained unclear was why.

“In many situations, people hold themselves back—consciously or unconsciously—from using their full strength,” Stephens explained. “Swearing is an easily available way to help yourself feel focused, confident and less distracted, and ‘go for it’ a little more.”

The answer, according to the new research, lies in a psychological state called disinhibition. When we swear, we essentially throw off the social constraints that normally govern our behavior, allowing us to push harder than we otherwise would. The researchers hypothesized that profanity puts people in a mental state where they feel liberated from their usual self-imposed limitations.

To test this theory, Stephens and his colleagues conducted two experiments involving 192 participants. Each person was asked to perform a chair pushup—an exercise requiring them to support their body weight using only their arms—while repeating either a swear word of their choice or a neutral word every two seconds. After completing the challenge, participants answered detailed questions about their mental state during the task.

The results confirmed what earlier studies had suggested: participants who swore during the exercise could support their body weight significantly longer than those repeating neutral words. More importantly, the researchers finally uncovered the mechanism behind this effect. The performance boost could be explained by increases in psychological flow—that immersive, focused state athletes and performers often describe—along with heightened self-confidence and a type of distraction that paradoxically helps rather than hinders.

This represents a significant advance in understanding human performance psychology. The phenomenon of swearing-induced strength gains was first documented by Stephens in 2009, when his laboratory discovered that people who cursed while plunging their hands into ice water could tolerate the pain roughly 60 percent longer than those who used neutral language. That original study found that swearing increased heart rate and decreased perceived pain, suggesting the body’s fight-or-flight response might be involved.

Subsequent research refined this understanding. A 2017 study presented at the British Psychological Society’s Annual Conference demonstrated that swearing produced measurable increases in both anaerobic power during cycling tests and isometric handgrip strength. Interestingly, the sympathetic nervous system activation that researchers expected to find wasn’t as pronounced as anticipated, suggesting something more complex was at work.

The new disinhibition framework provides that missing piece. Rather than simply triggering a stress response, swearing appears to work by freeing people from psychological barriers. It creates a mental environment where hesitation and self-doubt recede, replaced by confidence and focus.

“These findings help explain why swearing is so commonplace,” Stephens noted. “Swearing is literally a calorie neutral, drug free, low cost, readily available tool at our disposal for when we need a boost in performance.”

The practical applications extend beyond athletics. Nicholas Washmuth, a co-author from the University of Alabama in Huntsville, indicated that future research will explore whether swearing produces similar benefits in other contexts where people tend to hold back. “Our labs are now studying how swearing influences public speaking and romantic approach behaviors, two situations where people tend to hesitate or second-guess themselves,” he said.

There are caveats, however. Earlier research from Stephens’ laboratory found that the pain-killing effects of swearing are diminished in people who curse frequently in daily life. Like any tool, profanity appears to lose its edge with overuse. The emotional punch that makes swearing effective gets blunted when expletives become routine.

The findings also illuminate why swearing occupies such a unique place in human language. Unlike most speech, which originates in the left hemisphere of the brain, profanity appears to arise from deeper, more primitive emotional centers in the right hemisphere. This neurological distinction helps explain why swearing feels different from ordinary language and why it can produce such visceral effects.

For athletes, performers, and anyone facing a physical or psychological challenge, the research offers a counterintuitive piece of advice: sometimes, letting a curse word fly might be exactly what you need. Just maybe save it for when it counts.

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Endnotes

1. Stephens, R., Dowber, H., Richardson, C., & Washmuth, N. (2025). “Don’t Hold Back”: Swearing Improves Strength Through State Disinhibition. American Psychologist. https://doi.org/10.1037/amp0001650
2. American Psychological Association. (2025, December 18). Why swearing makes you stronger. EurekAlert! https://www.eurekalert.org/news-releases/1110041
3. Stephens, R., Atkins, J., & Kingston, A. (2009). Swearing as a response to pain. NeuroReport, 20(12), 1056-1060.
4. Keele University. (2017, May 5). New research finds swearing can make you stronger. Press release.
5. Stephens, R., & Umland, C. (2011). Swearing as a response to pain—Effect of daily swearing frequency. The Journal of Pain.