Jeremy Bailenson, the director of Stanford University's Virtual Human Interaction Lab, talks with Recode's Kara Swisher about his new book, "Experience on Demand: What Virtual Reality Is, How It Works, and What It Can Do." Bailenson came to Stanford to study how people can communicate with each other in a virtual world, but now his focus is on how VR can motivate us to eat less, help the homeless or have empathy with a person of another race, gender or age. He discusses why the technology has not yet taken off among consumers and why tech and media companies are wrong to think we should be spending hours at a time in a VR headset. Plus: Why telling a story in virtual reality is so much harder than telling one on a 2-D screen.