Power posing is a controversial self-improvement technique or "life hack" in which people stand in a posture that they mentally associate with being powerful, in the hope of feeling more confident and behaving more assertively. Though the underlying science is disputed, its promoters continue to argue that people can foster positive life changes simply by assuming a "powerful" or "expansive" posture for a few minutes before an interaction in which confidence is needed. One popular image of the technique in practice is that of candidates "lock[ing] themselves in bathroom stalls before job interviews to make victory V's with their arms."

Power posing was first suggested in a 2010 paper by Dana R. Carney, Amy Cuddy, and Andy Yap in the journal Psychological Science, and came to prominence through a popular TED talk by Cuddy in 2012. However, in 2015 several researchers began reporting that the effect could not be replicated, and, in 2016, Carney issued a statement abandoning the theory. Cuddy, however, continued her research, claiming to have evidence that posture feedback can at least make people feel more powerful. Today, power posing is often cited as an example of the replication crisis in the sciences.

The initial research on power posing was published in 2010. Dana Carney, Amy Cuddy, and Andy Yap claimed that high-power poses "produce power". The study included 42 participants, who were coached by researchers to assume a physical position of power. Hormone levels were measured before and after, and the authors stated that they found an increase in testosterone and a decrease in cortisol after posing. The researchers themselves suggested a range of possible real-world applications:

These findings suggest that, in some situations requiring power, people have the ability to "fake it 'til they make it." Over time and in aggregate, these minimal postural changes and their outcomes potentially could improve a person's general health and well-being. This potential benefit is particularly important when considering people who are or who feel chronically powerless because of lack of resources, low hierarchical rank in an organization, or membership in a low-power social group."

The researchers concluded that power posing induces lasting hormonal changes, which can lead to better outcomes in work-related situations, such as job interviews and wage negotiations.

The earliest criticism of Carney, Cuddy and Yap's work came from Steven Stanton, who noted their lack of attention to gender differences. "Carney et al. used a novel manipulation to ask an important question," he concluded, "but the degree to which their findings can be fully understood and implemented into future research is questionable without more complete analyses."

A 2015 article, published in Psychological Science by Ranehill et al. reported the results of a conceptual replication of the study using a larger sample. The researchers confirmed Carney et al.'s results about felt power but could not detect any physiological or behavioral effects of power posing. The statistical methods that may have led to the original erroneous findings were reviewed by Uri Simonsohn and Joseph Simmons of the Wharton School in a 2016 paper, concluding that the current body of research fails to "suggest the existence of an effect once we account for selective reporting".

In the years that followed, attempts were made by various research groups to apply power posing manipulation in different contexts. The results did not support the assumptions made by Cuddy et al. In a 2016 study by Garrison et al. the effect of posture manipulation was combined with dominant vs. submissive gaze. However, no effect was found on risk taking and, in contrast to original expectations, adopting an expansive pose reduced feelings of power. Deuter et al. (2016) investigated the effect of cognitive role taking and Cuddy's power posing manipulation in the Trier Social Stress Test; although role taking had an influence on the cortisol and testosterone response after stress, the posture manipulation had no effect on hormonal, behavioral or subjective measures.