Prof Panda is being a bit harsh here. Replications have been mixed. Cuddy and colleagues have studied how nonverbal expressions of power, such as expansive postures affect behaviour and hormone levels. Subjective reports of perceived personal power tend to be more affected than computational tasks or measures of hormones. Social psychology studies are going through a bit of a crisis at the moment, with new studies often unable to replicate previously seen effects. Whether the power pose will be further reinforced or undermined by new experiments remains to be seen.

Here is Amy Cuddy’s video about power poses on TED.