Some theories are so stupid that you can tell at the outset that elites will embrace them: Amy Cuddy's thesis of "power poses" is one of these. Launched in an academic paper in 2010, the theory that stance=success picked up a celebrated following. "A bigger boost came when David Brooks, The New York Times columnist and author of books like The Social Animal, about the everyday uses of psychology, visited the Harvard Decision Science Laboratory, where Cuddy is a researcher," Tom Bartlett wrote in The Chronicle Review on December 9, 2016. "He described in a column how the power-poses experiment...