In 2012, David Strayer found himself in a research lab, on the outskirts of London, observing something he hadn’t thought possible: extraordinary multitasking. For his entire career, Strayer, a professor of psychology at the University of Utah, had been studying attention—how it works and how it doesn’t. Methods had come and gone, theories had replaced theories, but one constant remained: humans couldn’t multitask. Each time someone tried to focus on more than one thing at a time, performance suffered. Most recently, Strayer had been focussing on people who drive while on the phone.