A doppelgänger is a mysterious, exact double of a living person. It’s a German word that literally translates to “double walker” or “double goer”. A doppelganger isn’t someone who just resembles you, but is an exact double, right down to the way you walk, act, talk, and dress. A friend or even a close relative who encounters your doppelganger will swear it was you, even though you can prove you were not in the location the double was sighted. Although the word doppelgänger is often used in a more general and neutral sense, and in slang, to describe any person who physically resembles another person, in German folklore it is used to described a wraith or apparition of a living person, as distinguished from a ghost. The concept of the existence of a spirit double, an exact but usually invisible replica of every man, bird, or beast, is an ancient and widespread belief. To meet one’s double is a sign that one’s death is imminent. The doppelgänger became a popular symbol of horror literature, and the theme took on considerable complexity. In The Double (1846), by Fyodor Dostoyevsky, for example, a poor clerk, Golyadkin, driven to madness by poverty and unrequited love, beholds his own wraith, who succeeds in everything at which Golyadkin has failed. Finally the wraith succeeds in disposing of his original. An earlier, well-known story of a doppelgänger appears in the 1815 novel The Devil’s Elixir, by the German writer of fantastic tales E.T.A. Hoffmann. In fiction and mythology, a doppelgänger is often portrayed as a ghostly or paranormal phenomenon and usually seen as a harbinger of bad luck. Other traditions and stories equate a doppelgänger with an evil twin. In modern times, the term twin stranger is occasionally used.

The doppelgänger effect — Ghost Cities