Popular Delusions IV: Hauntings

John Knott, the owner of Quadrille, a fabric and wall coverings company based in Manhattan, expected surprises when he bought a weekend home in the country, an 1839 Greek Revival house in Kinderhook in Columbia County, N.Y. Inconveniences were bound to crop up — a leaky roof, problematic plumbing, boiler issues. But he was not expecting ghosts.

—Kathryn Matthews, “This Old House Has Ghosts“. The New York Times, 13 October 2006.

Aside from belief in God and the associated religious trappings, one of the more widespread superstitions of society is the idea that spirits of the dead can return to haunt their former places of residence. A 2005 Harris poll found that 40% of Americans believe in ghosts, which would constitute tens of millions of people if this result was valid. (Incidentally, notice the number of people who believe in God according to this poll as compared to the same number from another Harris poll two years earlier.)

Reading the Times article, I noticed a significant attribute that the overwhelming majority of ghost stories have in common. See if you notice it as well:

A French guest was roused from a deep slumber at dawn — despite wearing earplugs — by repeated rapping noises on his bedroom door, though no one had knocked.

A visitor staying in an upstairs bedroom awoke to a startling vision of African slaves working in fields.

…a close friend, the New York florist Helena Lehane, cut a visit short after being beset by torturous nightmares; her screams — described by Mr. Knott as bloodcurdling — sent everyone running into her room.

Then a guest, Bill Placke, a banker from Summit, N.J., was dozing off in the guest bedroom, lying next to his sleeping wife, he said, when a smiling skeletal apparition robed in a white gown and ruffled collar appeared at the foot of his bed. It bobbed toward him, then vanished.

The majority of ghost sightings took place in people who were either asleep or drifting at the edge of sleep. These are the very conditions most suited for sleep paralysis. During REM sleep, though the brain is active, the body is paralyzed, an adaptation that prevents us from physically acting out our dreams. However, sometimes the mind becomes partially awakened while the body is still paralyzed and in its dream state, leaving a person with the frightening feeling of being fully conscious but unable to move or speak. More significantly, sleep paralysis is frequently accompanied by vivid hallucinations and the strong sense of a presence in the room. Sleep paralysis is a universal human phenomenon and has given rise to numerous cultural superstitions blaming demons or witches for its occurrence. In modern times, it has also inspired tales of alien abduction, as old myths are given a pseudoscientific slant, and it is very likely responsible for many ghost stories as well. It is not hard to see how a person in a twilight state between waking and sleep, experiencing the sensation of a looming presence, might come to believe that they have experienced a ghostly visitation – especially if that sensation is accompanied by vivid auditory or visual hallucinations produced by a brain still dreaming while awake. Cultural conditioning and expectation also plays a role; an experience that might have been shrugged off as no more than a nightmare in other circumstances, when it occurs in a supposedly haunted house or in a region famed for its spooks, will soon become further “evidence” for the existence of ghosts.

There is another relevant phenomenon that may explain a considerable number of ghost stories: infrasound. This is sound waves with frequencies below 20 hertz, too low-pitched for the human ear to perceive. Nevertheless, though we cannot consciously hear infrasound, it seems to have a subconscious effect on us. The linked article concerns a study undertaken at a concert in which some pieces of music were laced with inaudible infrasound. A substantial percentage of people hearing these pieces reported chills and feelings of anxiety, uneasiness and fear, as compared to the control group. Infrasound can occur both naturally and artificially, produced by phenomena such as ocean waves, wind and earthquakes, as well as by human artifacts vibrating at the appropriate frequency. It is quite possible that vibrations in old houses, caused by wind and weather or by the house itself creaking and settling, may generate infrasonic waves that can explain at least some reports of hauntings.

As with many popular delusions, however, the belief in ghosts lacks not just external evidence but internal coherence as well. For one thing, if hauntings can happen, why does everyone who dies not become a ghost? Why is every hospital, nursing home and old house not crowded with noisy poltergeists? Even if we restrict the list of potential ghosts to people who died violently or with unfinished business, the number of potential ghosts should scarcely decline. There have been millions of violent deaths throughout human history, after all, and probably the majority of people who die have unfinished business of some sort – death not generally being an event one can schedule. (The Times article quotes a home buyer who found that her allegedly haunted house was the site of at least two murders in its two-hundred-year-plus history. This breathless statistic seems less impressive, however, when one considers that most old houses have had people die in them.) If hauntings can really happen, we living humans should be outnumbered by the dead.

Another relevant question is this: Those who believe in ghosts often say that a restless spirit can remain for decades or even centuries, rattling its chains or giving people chills or doing whatever else it is a ghost does in its spare time. But any manifestation that has a physical effect on the world – even if the claimed effect is no more than moving air molecules – requires an expenditure of energy. This is the second law of thermodynamics, a basic physical principle. Living humans get the energy which we use to affect things in the world from the consumption of food. Ghosts are not known for eating, however, so where do they get their energy from? What is the power source that permits them to remain in the world for such long periods of time? Ghosts, it would appear, are doubly improbable: not only does the idea itself lack logical coherence, but any actual ghost would have to be a perpetual motion machine!

And on a related note, what is the substance that composes a ghost? In other words, what is a ghost made of? Everything that exists is either matter or energy, but neither is a suitable candidate for a spirit. If it is matter, then that means that ghosts, in some sense, have bodies like ours, and could theoretically be killed (again?) by the disruption of that material structure. But if it is energy, the prospects seem even poorer. For one thing, this would make haunting impossible, because energy does not stay in one place; it is always in motion, propagating from place to place at the speed of light. Rather than remaining to haunt the house of its death, any ghost in this circumstance would soon either be absorbed by nearby objects and cease to exist, or would be speeding off into interstellar space at 186,000 miles per second.

True believers may mock me for attempting to apply the laws of physics to ghost stories, asserting that ghosts are pure “spirit” or some other such thing not subject to the principles upon which the rest of the universe runs. Such comments betray a profound isolation from reality. These beliefs are relics of a superstitious past, and fail to accord with everything we have learned in the last few hundred years about the way the universe works. Talk of “spirit” is just the old wine of superstition and magic poured into new bottles of vaguely scientific jargon. (Here is one typical example of the genre, an alleged explanation of ghosts that really just consists of randomly selected scientific terms pasted together in a meaningless hodgepodge.) As with many popular delusions, these beliefs have stayed the same while the world has moved on around them. They may still be valuable for a brief and entertaining jolt of thrills, but we should cease pretending that they have anything at all to do with the real world.

This seems a good place to debunk a related conceit; the self-proclaimed “ghost hunters” who spend countless hours poring over recorded white noise until they happen to hear a snatch of static (or a stray radio broadcast) that sounds a little like a voice, or who claim to detect spirits in photographs that are really just optical flaws in the camera or light reflected from dust or precipitation. This activity has all the value and relevance to reality of claiming that there really are dragons and crabs and sailing ships in the clouds: it speaks volumes about the human mind’s ability to find patterns in noise, but says nothing at all about what exists in the external world.

In closing, and lest I forget: Happy Halloween, everybody! May you walk with confidence in the knowledge that there is nothing in the night more fearful than our own imaginations.

Other posts in this series:

Book Review: 1491
The Pope's Laudato: So Close And Yet So Far
When Rationalists Reinvent Religion
The World in the Dark
About Adam Lee

Adam Lee is an atheist writer and speaker living in New York City. His new novel, Arc of Fire, is available in paperback and e-book. Read his full bio, or follow him on Twitter.