The Ghost Experiment
Why ghosts give us chills even if we don't believe in them
To Believe or Not to Believe
I love ghosts. Or, I love the idea of ghosts.
I don’t believe that ghosts exist, though I suppose I’m open to the idea in some ways. There’s a lot we don’t understand about the natural world. But, based on my understanding of how the world operates, there isn’t really a place for ghosts. My conception of nature would have to shift quite a bit to accommodate the existence of a traditional ghost.
And yet, despite this, I love the idea of ghosts.
In my book, I tell a story about one of the paranormal investigations I took part in and how the experience got me thinking about why ghosts are so compelling to our minds.
At one point during the investigation, I was standing in the basement of an old mansion. It was fairly dark, but I could tell that nobody in our group was within a few feet of me. Suddenly, I felt a very clear brush on my right leg, as if someone had run their fingers across it. I quickly turned around and looked behind me to see… nothing.
Goosebumps immediately filled my body. I, or at least some part of my mind, knew that nothing had touched me. But a different part of my mind had other ideas about what had happened. Just seconds later, another one of the investigators let out a small yelp. She had felt something touch her hand not far from where I was standing.
I only got chills one other time that night.
A long, uninterrupted stretch of floor encased by a wall with two doorways runs along one edge of the basement we were in. At one end is a single wooden chair, positioned such that it is looking down a dark cavity of the hallway. Apparently, the ghost of a revolutionary soldier is often spotted in this area of the basement.
One man from our group decided to sit in the chair and see if he could see or hear anything. After only a minute or so, he walked through the doorway closest to the chair looking visibly shaken. He didn’t say much other than he was sure he saw a shadowy figure staring back at him in the hallway.
Intrigued by this, I decided to go sit in the chair for myself. After all, ghosts don’t exist.
Right?
My mind was telling me that ghosts don’t exist, but my body was reacting as if this soldier was very real, angry, and waiting for me in the hallway.
I sat alone in the chair, staring down the long, dark hallway. My eyes darted back and forth—did I see a shadow? Was that a face? My mind raced through possible scenarios. I got an uneasy feeling that was difficult to explain and even harder to shake. It felt as if something was wrong, but I couldn’t identify what it was.
We are primed to over-detect danger, to feel watched in the dark, and to react even when we “know better.”
I don’t think I saw the ghost of the soldier because I don’t believe that ghosts exist. But some part of my mind was convinced that something might be out there in the dark, and it was telling my eyes to be vigilant. Each time I thought I saw something, my mind latched on to the idea that it was most likely the soldier’s ghost. My heart raced at each shifty shadow. I kept telling myself it was nothing, but the threat detector in my mind simply wasn’t having it.
Why were my mind and body reacting as if the ghost of the soldier was in the room even though I don’t believe in ghosts? Why couldn’t I help but see and feel what I knew wasn’t there?
The Ghost in the Lab
Psychologist Jesse Bering and his colleagues have shown that I’m not alone in this dissonant experience.
The researchers designed a clever set of studies on ghost perception that were disguised as meditation studies. Before participants arrived, they completed a questionnaire about their afterlife beliefs. Then came the experimental setup: half of the participants were told a janitor had recently died in the testing room and even signed a "notice of death on premises" form. During this process, a PhD student casually mentioned that they saw a ghost in the room just a few days earlier.
The other half of the participants were told nothing about a death or ghost in the room.
When you’re in a fearful situation, your body becomes more physiologically aroused. As part of this process to prepare you for fight or flight, your heart rate increases and you begin to sweat slightly, the latter of which increases the electrical conductance of your skin. Because of this, your heart rate and skin conductance can be used as proxy measures of how physiologically aroused, and how prepared for fight or flight, you are.
The researchers took advantage of this and hooked up the participants to instruments that measured both heart rate and skin conductance under the guise of measuring relaxation. They then left the participants alone in the room, where they listened to a nine-minute recording on how to engage in mindfulness.
After the mindfulness recording finished, the participants were asked to sit in complete silence for six minutes and use the mindfulness tools they had just learned to contemplate a problem they were experiencing in life. During this task, each participant sat alone in a quiet room that was illuminated only by a small desk lamp.
In the middle of the six-minute meditation task, a researcher in another room secretly turned off the lamp using a remote control. The participant sat in complete darkness for seven seconds before the light turned back on.
As it turns out, a flickering light is a bit scarier when someone tells you a ghost was recently seen in the room.
Our Haunted Minds
Participants in the experimental group, who were told about the death of the janitor and the reports of a ghost in the room, had higher heart rate and greater skin conductance after the light-flickering incident than did those in the control group who didn’t hear anything about a death or ghost in the room.
Those who heard about the ghost were subconsciously preparing for danger, and their physiology was showing it. Interestingly, a participant’s physiological response to the flickering light didn’t depend on their belief in an afterlife. Afterlife believers and nonbelievers alike showed increased physiological arousal in response to the light flickering in the experimental condition.
While the nonbelievers may not have consciously believed that a ghost caused the light to flicker, their minds and bodies responded as if an otherworldly agent was responsible for the disturbance. Much like my creepy experience with the soldier’s ghost in the basement, the nonbelievers in this study couldn’t help but feel uneasy.
We’re wired to be vigilant. When something feels off, our minds and bodies respond, sometimes before we consciously know why. That edge of unease we feel in dark basements or during flickering lights isn’t just superstition or imagination. It’s a deeply ingrained survival mechanism, shaped by evolution and reinforced by culture.
Humans are uniquely social creatures. We learn much of what we know from each other, especially when it comes to danger. For most of human history, it would have been a fatal mistake to ignore a potential threat that someone claims to have seen. Those who took caution were the ones who survived and whose genetic legacy still lives on today.
Ghost stories tap into ancient circuitry of our minds that evolved in response to threats around us. We are primed to over-detect danger, to feel watched in the dark, and to react even when we “know better.” The dangers of our species’ past still haunt our minds today, leaving us prone to reacting to what might not be there.
Have you ever felt or seen something that you weren’t sure existed? It could be a ghost, alien, or some other being that doesn’t fit well in the accepted structure of the world. Let me know in the comments.
And of course, if you enjoy this type of content, be sure to pre-order my new book, Morbidly Curious: A Scientist Explains Why We Can’t Look Away. Doing so gets you 3 free months to the paid version of my Substack. Just email your a screenshot of your pre-order confirmation to MorbidlyCuriousBook@gmail.com.