Alison Gopnik's career began with a psychology experiment she now considers ridiculous. Aiming to understand how 15-month-olds connect words with abstract concepts (daddy caregiver), she decided to visit nine kids once a week for a year. The then Oxford graduate student would record everything they said as part of her dissertation. "It was absurd for a million reasons," says Gopnik, holed up on a winter Friday in her office at the University of California at Berkeley, where she is a professor of developmental psychology. "If a childhad moved away, if there weren't any take-aways after the year, or any number of things, all that work would have been gone," she says, before adding, "I would never allow a student of mine to do anything like that today."