The psychology of possibility.

An interesting article in the Harvard Magazine describes the life work of Ellen Langer, her demonstrations that our social self image (old versus young, for example) strongly patterns our actual vitality and physiology, her work on Mindfulness, unconscious processing, etc. I recommend that you read the article. Here are some clips from its beginning that hooked me (I actually did my own mini-repeat of the experiment described, a simple self-experiment of pretending that I had been transported back in time to 40 years ago, and convinced myself I was experiencing some of the effects described)...

In 1981, early in her career at Harvard, Ellen Langer and her colleagues piled two groups of men in their seventies and eighties into vans, drove them two hours north to a sprawling old monastery in New Hampshire, and dropped them off 22 years earlier, in 1959. The group who went first stayed for one week and were asked to pretend they were young men, once again living in the 1950s. The second group, who arrived the week afterward, were told to stay in the present and simply reminisce about that era. Both groups were surrounded by mid-century mementos—1950s issues of Life magazine and the Saturday Evening Post, a black-and-white television, a vintage radio—and they discussed the events of the time: the launch of the first U.S. satellite, Castro’s victory ride into Havana, Nikita Khrushchev and the need for bomb shelters.

...Before and after the experiment, both groups of men took a battery of cognitive and physical tests, and after just one week, there were dramatic positive changes across the board. Both groups were stronger and more flexible. Height, weight, gait, posture, hearing, vision—even their performance on intelligence tests had improved. Their joints were more flexible, their shoulders wider, their fingers not only more agile, but longer and less gnarled by arthritis. But the men who had acted as if they were actually back in 1959 showed significantly more improvement. Those who had impersonated younger men seemed to have bodies that actually were younger.