Training fads usually survive on little more than their followers' enthusiasm and myths about our brains.
But there is plenty of hard evidence about effective ways for adults to learn. That evidence from thorough research is useful for anyone who teaches, coaches or mentors adults.
Call it blind faith if you like, but the rewards of believing that people are on their way to being first-class are enormous and backed by the research.
Since an influential study in American classrooms in the 1960s established the power of the self-fulfilling prophesy, there have been hundreds more. Our belief in their potential or ability can be a useful motivator for children and adults.