Buzz
Most of us have come across at least one ghost tale during our lives. It seems the supernatural has touched everyone and every place in some form. Statistically, approximately 45% of Americans claim belief in ghosts, and as many as 18% report having encountered a spirit firsthand. This is a significant number for something that might be dismissed by some as a mere hoax.
Various theories exist about the true nature of ghosts. Could there be scientific reasons for that eerie shadow following you in an abandoned house? Or the unexplained chill creeping down your spine in a dark room? And what about demons—do they truly invade our world, leaving claw marks on our backs as we sleep?
Let’s explore ten theories rooted in science that may explain these paranormal experiences, instead of attributing them to the supernatural.
10. Sleep Paralysis
Perhaps the most common explanation for ghost sightings is sleep paralysis. Dr. Baland Jalal, a neuroscientist at the University of Cambridge, describes sleep paralysis as 'dreaming with your eyes open.' He explains that during REM (Rapid Eye Movement) sleep, we experience incredibly vivid dreams, while our eyes can move rapidly under closed eyelids. However, our bodies remain still to prevent us from acting out our dreams, which can sometimes lead to the sensation of paralysis.
Many typical paranormal occurrences can actually be attributed to this neurological phenomenon: hallucinations, the feeling of a presence sitting or lying on your body, and even the sensation of being scratched by a demon. While it feels entirely real, you were likely caught in a terrifying waking-dream state.
9. The Power of Suggestion
Suggestion is a potent tool, and numerous studies have been conducted on its influence. However, it’s only recently that we’ve begun to explore the role of suggestion in relation to paranormal experiences. In fact, one might argue that the entire Spiritualist movement is based on this concept of illusion.
In 2003, Richard Wiseman ran two experiments published in the British Journal of Psychology to investigate the power of suggestion in the context of a séance. His goal was to understand whether belief in the paranormal made participants more susceptible to suggestion. The first experiment involved a fake medium leading a séance, where the psychic suggested that the table had moved. About one-third of the participants later claimed the table had moved, even though it had remained still throughout. Believers in the paranormal were more likely to misreport the event than skeptics.
Believers in the paranormal were more likely to accept the suggestions made by the medium during the next series of fake séances than non-believers. However, there was a catch: they only reported an event when the suggestion matched their personal belief in the paranormal. For instance, if the medium suggested that an object hadn't moved when it actually had—through trickery—believers were no more likely to agree than non-believers. In total, about one-fifth of the participants believed they had witnessed authentic paranormal occurrences.
It remains unclear whether the verbal suggestions directly influenced the participants' perception or memory of the events, or perhaps both. However, the participants' existing belief in the paranormal did influence how likely they were to claim a paranormal event had occurred, even if it didn’t. This could be due to true belief, suggestion, or demand characteristics—subtle cues from the experimenter that guide participants to behave or respond in a certain way. Regardless, a significant portion of participants reported that objects had moved and they had experienced genuine paranormal phenomena.
8. A Mysterious Planet
It might seem like a cheat, but sometimes supernatural events can be explained by unusual, yet natural phenomena that occur on Earth every day.
Take the Oracle of Delphi, for example. The Pythia's trance state was considered by some to be supernatural and paranormal. She could communicate with spirits, gods, and other mystical beings to predict the future. People traveled from far and wide to witness her visions and hear her speak to these invisible entities. Was it all a hoax? Probably not. Scientists largely agree that hydrocarbon gases from the bituminous limestone beneath Delphi likely induced the trance state in the Pythia.
A geological team from Wesleyan University discovered ethane, methane, and ethylene in spring water near the Oracle. Could the mystical fumes within the Oracle's cave simply have been extremely toxic gases? While we might not all experience ghostly visits from our long-departed relatives due to faultline gas poisoning, many ancient supernatural tales come from an era when poorly regulated furnaces, mercury-tainted food and drink, and candles casting eerie shadows were common. Over time, these stories were passed down, modified, and modernized into the ghostly tales we know today.
7. Low-Frequency Sounds
If you're familiar with ghost hunting TV shows, you’ve likely heard of EMF readers. These devices supposedly detect ghosts by measuring electromagnetic fields in a room. If the frequency is high enough, ghosts might appear and move objects. The problem with EMF meters is that they’re highly unreliable, with everyday items like cellphones and camera batteries triggering them. However, there is some science behind EMF and its link to ghostly behavior.
The phenomenon is known as the “fear frequency.” Humans, especially adults, struggle to hear low-frequency sounds below 20 Hertz (also called infrasound). Despite this, the body can still sense these sounds, often triggering feelings of unease, chills, or 'nervous feelings of revulsion and fear.'
This theory provided an explanation for a local ghost story. On Coventry University’s campus, a 14th-century cellar was said to be haunted. But when lecturer Vic Tandy investigated, he discovered infrasound levels in the room that could account for the eerie experiences. So, is it really a ghost creeping you out? Probably not. It’s just your body reacting normally to its environment.
6. Mold and Fungus
Let’s be honest, if you step into a dilapidated hospital or an abandoned house, you're likely to feel uneasy about potential ghostly encounters. Perhaps the wiring is fine, so we don’t need to worry about EMF. There’s no one else around for miles, so human influence is out of the equation. But what about black mold, asbestos, or rye ergot? There's a high chance that toxic molds are present in the damp basements, crumbling ceilings, and sealed rooms of these decaying buildings, not to mention floating in the air.
It’s possible that many of the ghostly experiences are simply a result of poor air quality in 'haunted' locations. Shane Rogers, an Associate Professor of Civil & Environmental Engineering, noted, 'The links between exposure to toxic indoor molds and psychological effects in people are not well established; however, many hauntings are associated with buildings that create prime conditions for mold and other indoor air quality problems.'
The mold theory could also explain what some paranormal investigators refer to as 'demonic activity.' On TV, you might see someone suddenly feel sick, experience a choking sensation, or suffer from headaches and dizziness when encountering an evil spirit. Yet, they instantly feel better once they step outside for fresh air. While this could be an actor’s performance, these symptoms can also be a direct result of exposure to toxic mold and fungus. Sorry to disappoint, but it’s likely not a demon—it’s your body telling you to get out and breathe fresh air.
5. Mind/Body Disconnect
If you’ve ever felt like a ghost or some other supernatural being was near, it could be due to a glitch in how your brain processes self-awareness and spatial orientation. The brain is an intricate organ and can generate supernatural experiences, even when your body isn't consciously aware of it. When the brain misrepresents our body's position in space, it might create an additional perception of the body that is no longer identified as 'me,' but as something else—a 'presence.'
To prove this, a team of Swiss neuroscientists figured out how to replicate ghostly experiences in a lab. The researchers examined the brains of twelve patients who suffered from neurological disorders and reported encounters with ghosts. MRI scans revealed abnormal activity in three brain areas responsible for self-awareness, movement, and spatial positioning.
Next, the scientists studied a group of twelve healthy volunteers. They blindfolded the participants and instructed them to move their arm in a specific way. Each person was connected to a robot in front of them (the main robot), while a second robot was placed behind them (the secondary robot). Unbeknownst to the participants, the second robot mimicked the arm movements on their back. For instance, if the participant made a circle and triangle with their arm, the secondary robot would lightly trace the shapes on their back.
When the second robot performed the movements in sync with the participants' arm, no unusual sensations were reported. However, when there was a slight delay between the movements, disrupting the participants' sense of timing and space, several participants reported feeling a presence around them. Some even claimed there were ghosts in the room. A few participants became so uneasy that they requested to leave before the experiment was completed.
4. Pareidolia
Once again, the sensation of a ghost might simply be your brain experiencing a self-awareness glitch. This time, it’s a completely normal and natural phenomenon called pareidolia. Pareidolia is the brain’s ability to see images in clouds or detect faces on objects—think of the image of the Virgin Mary on a grilled cheese sandwich.
Pareidolia is an ancient skill that may have aided our early ancestors by helping them spot potential threats in their surroundings—was that movement in the grass something to worry about? In his 1995 book, The Demon-Haunted World: Science as a Candle in the Dark, Carl Sagan popularized the idea that pareidolia is the reason we perceive certain ghostly figures.
It’s a phenomenon that helps explain how our brains interpret light, shadows, or distant shapes on a foggy battlefield. There might indeed be something there, but your brain fills in the blanks to create an image that isn’t actually present.
3. Positive and Negative Ions
Although it might sound like something straight out of Ghostbusters, ions and proton packs actually have a basis in real science when it comes to exploring the supernatural. By definition, a negative ion is an atom with an extra electron in its shell, while a positive ion has one less.
Some paranormal researchers suggest that spirits might disrupt the natural ion balance in the atmosphere, while others believe that ghosts harness the energy from these ions to manifest or interact with the physical world. I wouldn’t put too much stock in ghost hunters using ion meters, though. The technology is notoriously unreliable. Ions are produced by natural events like weather patterns, solar radiation, and radon gas. Ultimately, how one interprets the results depends on their perspective.
Positive and negative ions have an impact on our mood. Negative ions are known to induce feelings of calm and relaxation, while positive ions can lead to headaches and nausea. This might explain why people living in “haunted” houses often report fatigue, headaches, or general illness. When they experience an ion imbalance, they may mistakenly attribute it to paranormal forces rather than a natural cause.
2. Unprocessed Trauma
I’m not a therapist, but one common explanation for why the living might perceive the dead is linked to how our brain processes, or fails to process, trauma.
Dr. Lenore Terr, in a study conducted between 1974 and 1984 involving 88 psychiatric patients, proposed that many ghost sightings are actually hallucinations or illusions triggered by traumatic, life-threatening experiences. PTSD sufferers have reported seeing, hearing, or feeling the presence of ghosts or other entities. For example, children who were attacked by animals described being haunted by animal spirits. More recent research has shown that certain mood and anxiety disorders can also influence these experiences, with some patients admitting to hallucinations, delusions, or odd beliefs.
After a traumatic experience, some individuals may start to believe they have gained psychic abilities. Intense trauma can lead to hallucinations where the brain, in an attempt to process emotional pain, creates external visions or voices. This trauma could stem from an immediate event, such as a car accident, or from prolonged experiences like domestic violence or child abuse. If a person is unable to face or process this trauma, they may start to perceive or believe in apparitions and paranormal phenomena. These occurrences could be the unconscious mind’s way of forcing the person to confront their unresolved issues, leading to the eventual cessation of the 'haunting.'
1. Energy Displacement
Bear with me here—this theory draws on Einstein’s work to support the idea of ghosts. Let’s assume that ghosts are real, and rather than being a supernatural occurrence, their existence can be explained through a scientifically valid theory about why they appear in our world.
John Kachuba, a paranormal researcher, discusses in his book Ghosthunters, 'Einstein proved that all the energy in the universe is constant and cannot be created or destroyed… So what happens to that energy when we die? If it can’t be destroyed, it must transform into another form of energy. What could that new energy be? Could we call it a ghost?' (LINK 4) It’s hypothesized that the energy that keeps our bodies functioning could also be responsible for the manifestation of spirits. This is why ghost hunters often rely on devices to measure this type of energy.
Einstein’s theory remains valid, and science does explain what happens to energy when we die. However, the conclusion isn’t that we become ghosts. Upon death, the energy within the body is transferred to the environment, where all energy from living beings ultimately goes. This energy is released as heat. If an animal or insect consumes the body, or plants absorb the nutrients from the decomposing body, that energy is passed into these creatures. When cremation occurs, the body’s energy is released as heat and light.
Take a moment to think about plants and animals. Have you ever encountered a ghost cow? Or a ghost Venus Flytrap? Probably not. When we consume dead plants and animals, we are absorbing their energy and converting it for our own use. Our bodies process food into energy, completing the natural cycle. The idea that a person’s energy persists long after their body is gone seems unlikely. Rather than existing as a spirit composed of electromagnetic energy, our energy is transferred into heat and chemical energy.
