Intelligence has always been considered principally an inherited trait. Whatever you're born with, is what you get. But a new study flies in the face of that commonly held belief and shows that it's actually possible to increase one's brainpower. The key, researchers say, is training in working memory, the kind that allows memorization of a phone number long enough to dial it. Larry talks with Susanne M. Jaeggi, a postdoctoral fellow in psychology at the University of Michigan and co-author of the study "Improving fluid intelligence with training on working memory," and Nahmoo Soh, a junior at the University of Michigan who participated in the training.