A groundbreaking 1981 study that showed that it is not our physical state that limits us, but our mindset about our own limits, is set to feature in a movie starring Jennifer Aniston. Harvard psychology professor Ellen Langer's research saw men in their seventies and eighties pretend they were young men, once again living in the 1950s. What she found surprised even her own team of researchers — after just one week, there were dramatic positive changes across the board. "Both groups were stronger and more flexible." “Wherever you put the mind, the body will follow,” Langer recently told a lceture audience.