NPR Science reporters Alix Spiegel and Lulu Miller explain to Ira Glass how they smuggled a rat into NPR headquarters in Washington, and ran an unscientific version of a famous experiment first done by Psychology Professor Robert Rosenthal. It showed how people’s thoughts about rats could affect their behavior. Another scientist, Carol Dweck, explains that it’s true for people too: expectations affect students, children, soldiers, in measurable ways. (6 minutes)