From Harry Styles, to Dev Patel, to Jeremy Allen White — dozens of celebrity lookalike competitions have popped up in recent weeks. But why are doppelgängers all the rage, when they used to be a sign of bad luck? Nathaniël Siri and Edward Toledo are two lookalikes who say that they share similar interests and traits. However, a psychologist says not all doppelgängers share much in common aside from their looks.