To understand these questions, it first helps to consider what psychologists call the theory of mind. Put simply, it's the recognition that other people have brains in their heads that are busy thinking, just like ours (usually) are. The theory comes in handy on the road. Before we venture into a crosswalk, we might first make eye contact with a driver and then think, He sees me, so I'm safe, or He doesn't, so I'm not. It's a technique we likely use more than we realize, both behind the wheel and on our feet. "We know how other people are going to act because we know how we would act," explains Azim Shariff, an associate professor of psychology at the University of British Columbia, who has written about this issue in the journal Nature Human Behaviour.