The Mary King’s Ghost Fest, which began last Friday, is a 10-day celebration of all things spooky: talks and walks and even a bit of ghost hunting. But the only really strange thing about it is why nobody ever thought of doing it before.

To outsiders, ghosts have always lingered in the Celtic mists. “There was thought to be an indefinable something about Scotland,” write Mary Holmes and David Inglis of Aberdeen University, “that made those who would never otherwise have entertained the existence of supernatural creatures in their normal lives in London or Leeds, prick up their ears at stories of fairy folk and tormented souls.”

That something has lingered until spookiness became as integral a part of Scotland’s identity as whisky or tartan. And where should it manifest itself more than in Edinburgh’s old town? If you set out to design places for haunting, you would have a hard time bettering the capital’s vaults and cellars. Throw in a clutch of impressively ancient graveyards and the city seems uniquely equipped to be Britain’s ghost capital.

What the organisers of the Ghost Fest have come up with is a mixture of history and hokum, with a dash of science thrown in.

At the National Library, Louise Yeoman, the historian, will lecture on why Scotland is supernatural, the Mitre pub is holding an evening of ghostly storytelling and next Saturday, Dr Peter Lamont of Edinburgh University dissects the original Indian rope trick.

There’s much more, but inevitably some of the most intriguing events take advantage of the city’s unique subterranean architecture. Mary King’s Close — the old town street that was buried intact when the city chambers were built in the 18th century — is often said to be one of the most haunted parts of the city. The first documented apparition, from 1685, is recorded in George Sinclair’s compendium of supernatural tales, Satan’s Invisible World Discovered. When Thomas Coltheart and his wife moved into the close they were greeted one Sunday by a man’s disembodied head floating in the air, a phantasmal child and a ghostly dog and cat. It shouldn’t have been a surprise: their maidservant had already fled claiming the house was haunted.

Professor Richard Wiseman, a psychologist at the University of Hertfordshire, is a former researcher at Edinburgh University’s Koestler Parapsychology Unit (and sometime collaborator with Derren Brown, the illusionist). He is a sceptic, debunking the claims of psychics as he flies the flag for scientific reason.

Many ghost stories, he argues, satisfy basic human needs for reassurance. “The desire to believe in survival after bodily death is obviously a strong one,” he says. “Then you find that many ghost stories are about revenge for misdoings.

“They support the hypothesis that, however unfair this life may seem, the universe is ultimately a just place. And thirdly there’s the notion that sometimes people are lost and we can help them.”

All of which means that, when people say they have no reason to believe a “supernatural” experience that has happened to them, they are unlikely to be speaking objectively. Put it another way: if ghosts didn’t exist, we would need to invent them.

Yet Wiseman is careful not to dismiss apparently paranormal experiences out of hand.

“I think there is something going on,” he says. “One of the interesting things about Mary King’s Close is the consistency of people’s reports in different parts of the site. One of the things I’m interested in is whether the visual aspects of certain locations create what you might call stereotypes in people’s heads.

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