If you've ever felt like someone was watching you, you may have attributed that awareness to a sense of unease or a prickling on the back of your neck. But there's nothing psychic about it; your brain was simply picking up on cues. In fact, your brain is wired to inform you that someone is looking at you even when they're not. "Far from being ESP, the perception originates from a system in the brain that's devoted to detecting where others are looking," writes social psychologist Ilan Shrira. This concept may sound confusing, but it actually makes a lot of...