“They were suppler, showed greater manual dexterity and sat taller … Perhaps most improbable, their sight improved. Independent judges said they looked younger.” How did these test subjects become younger? They acted younger. In the NYT Magazine, Bruce Grierson examines the science related to one of life’s most hopeful adages: What if age is nothing but a mind-set? Youth is wasted on the young. Maybe I’ll finally get to waste some of it on myself.