In 2010 Dana Carney, Amy Cuddy and Andy Yap reported in Psychological Science that holding an expansive “power pose” raised testosterone and lowered cortisol. The study had 42 participants. In June 2012 Cuddy presented the idea in a TED talk. By 2017 about 47 million viewers had seen it.
In 2015 a larger replication found that people felt more powerful after posing, but it found no physiological or behavioral effects. In 2016 Carney wrote: “I do not believe that ‘power pose’ effects are real.”