Doppelgängers – urban legend or scientific phenomenon? Last week, a Dublin University student, Niamh Geaney, found her own ‘double’, Karen Branigan, on Facebook following a challenge she and her friends set themselves to find their twin strangers from anywhere in the world. The resemblance between the two women is uncanny, and Niamh reportedly found Karen, whom she says looks “closer than some of my sisters”, in just two weeks. While in a video posted on YouTube they appear thrilled to have discovered each other, in the past, encounters with one’s ghostly double have been seen as a bad omen and often associated with ill fortune or death.

The idea of the doppelgänger (literally double-goer or double-walker) has fascinated people for centuries, appearing in a variety of art forms, folk tales and urban myths. According to legend, every person has a doppelgänger – an identical ‘twin’ with no actual relation to you. If you saw your double, it was usually considered a good idea to run away as fast as possible.

The association of the doppelgänger with terror meant that it quickly became a staple motif of gothic fiction, most famously, perhaps, in Robert Louis Stevenson’s Strange Case of Dr Jekyll and Mr Hyde. By means of a potion, Dr Jekyll is able to transform into his alter ego, Mr Hyde, who embodies the latent, suppressed evil within Jekyll’s self. In giving reign to the monstrosity of Hyde, Jekyll can indulge in the irresponsibility of a life of debauchery and self-indulgence without having to shoulder the consequences. “Man is not truly one, but truly two,” is the message of the novel – a theory that has also been explored in the writings of Byron, Mary Shelley, Edgar Allen Poe and others.

Fyodor Dostoevsky’s novella The Double, for example, brings together two versions of a single person. The titular councillor Golyadkin encounters his exact double multiple times and forms a growing but uncomfortable relationship with him. While eschewing the traditional separation of the doubles into good and evil, Dostoevsky nevertheless creates an opposition between the anxious, socially-awkward and mentally-troubled protagonist and his confident and suave duplicate. The story traces Golyadkin’s slide into a psychological breakdown and ends with him being carried off to a mental asylum, his self-identity having been destroyed by his experience.

But the doppelgänger is by no means restricted to the realms of fiction. Reports of real-life encounters are found throughout history, almost invariably accompanied by death. Percy Shelley claimed to have met and conversed with his doppelgänger shortly before he drowned. Queen Elizabeth I was reportedly terrified to witness a lifeless double of herself lying in her bed days before she died. Abraham Lincoln saw his in a mirror over his shoulder. The list goes on. Does the most recent example of Niamh and Karen mean that the legend has any real credence?

Probably not, although it is certainly a thought-provoking concept. Everyone, at some point, wonders about the person they could have been but weren’t. Self is not a characteristic but a choice, and it is not so unrealistic to think that we all have alternative versions of ourselves. If not somewhere else in the world, then buried deep within.