An esper is a person believed to possess extrasensory perception, or ESP, the supposed ability to acquire information or influence the physical world through means beyond the five known senses. The term was coined by science fiction writer Alfred Bester in his 1953 novel “The Demolished Man” and has since become shorthand for anyone with psychic abilities, appearing widely in fiction, parapsychology, and pop culture. Whether espers actually exist is one of the most debated questions in psychology and neuroscience.
The Four Types of Esper Abilities
Parapsychology, the field that studies these claims, traditionally breaks esper abilities into four categories. Telepathy is mind-to-mind communication without using speech, gestures, or any normal sensory channel. Clairvoyance is perceiving information about distant locations you have no way of seeing. Precognition is gaining knowledge of future events, often through visions or dreams. And psychokinesis (sometimes called telekinesis) is manipulating physical objects using only the mind.
These four categories cover nearly every psychic claim you’ll encounter, from fortune-telling to spoon-bending. In fiction, espers typically specialize in one or more of these abilities, and the same framework carries over into how researchers design experiments to test real-world claims.
How Scientists Have Tested ESP
The most famous laboratory studies of esper abilities were conducted by J.B. Rhine at Duke University starting in the 1930s. Rhine used a deck of 25 Zener cards, each printed with one of five symbols (circle, cross, wavy lines, square, star). A subject guessing randomly should get about 20% correct. Rhine’s star subject, Hubert Pearce, averaged 40% correct across extensive testing in 1932, double the expected rate. In the most well-known experiment, Pearce sat in a campus library cubicle while a research assistant shuffled and recorded cards in a lab 100 to 250 yards away. Over 37 runs of 25 cards each, Pearce’s scores consistently deviated above chance regardless of distance.
These results generated enormous excitement, but also sharp criticism. Pearce had been allowed to physically handle the cards in earlier tests, and skeptics pointed to insufficient controls against sensory leakage, subtle cues, or recording errors. Rhine’s work did, however, produce something lasting: his 1940 book “Extra-Sensory Perception After Sixty Years” is now recognized as the first meta-analysis in the history of science, compiling every experimental study of clairvoyance and telepathy up to that point.
What Modern Experiments Show
The most widely used modern test for ESP is the Ganzfeld experiment. A “receiver” sits in a state of mild sensory deprivation (eyes covered, white noise playing) while a “sender” in another room concentrates on a randomly selected image or video clip. The receiver then tries to identify the correct target from a set of four options. Pure chance would produce a 25% hit rate.
A large registered meta-analysis published in 2024, covering more than 40 years of Ganzfeld studies from 1974 through 2020, found a statistically significant but very small effect. The average hit rate was about 6.8% above chance, corresponding to an effect size of roughly 0.08. The statistical significance was strong (p = .0009, with a Bayes factor of about 90 in favor of a real effect over pure chance), but the practical size of that effect is tiny. To put it in perspective, it means that instead of guessing correctly 25% of the time, participants averaged around 31% to 32%.
What this means is genuinely contested. Proponents argue that even a small, consistent effect across hundreds of studies points to something real. Skeptics counter that an effect this small is exactly what you’d expect from subtle methodological problems, publication bias (where studies finding nothing are less likely to be published), or minor procedural inconsistencies accumulated across decades of experiments from different labs with varying standards.
Why So Many People Believe
Surveys consistently find that belief in ESP is remarkably common. Research indicates that around two-thirds of Americans report believing in at least some form of psychic phenomena. Several well-understood psychological mechanisms help explain why.
The Barnum effect is one of the most powerful. It describes people’s tendency to accept vague, general personality descriptions as uniquely accurate about themselves. A psychic who says “you’ve recently experienced a loss or disappointment” is making a statement true of virtually everyone, but it feels personal. Professional “cold readers” exploit this systematically, combining general statements with careful observation of a person’s reactions to appear uncannily accurate. Confirmation bias compounds the effect: people remember the hits and forget the misses. If you think of someone moments before they call, that sticks in memory. The hundreds of times you thought of someone and they didn’t call simply fade away.
Brain-Computer Interfaces and “Synthetic Telepathy”
While evidence for biological ESP remains thin, technology is producing something that looks remarkably like it. Brain-computer interfaces (BCIs) use tiny microelectrode arrays, each smaller than a baby aspirin, implanted on the brain’s surface to read neural activity and translate it into words or actions through machine learning.
Researchers at Stanford recently demonstrated that these devices can decode not just attempted speech (where a paralyzed person tries to move their mouth) but also “inner speech,” the silent internal monologue you experience when thinking in words. The inner speech signals turned out to be a smaller version of the same patterns produced by attempted speech. Accuracy for inner speech decoding isn’t yet as high as for attempted speech, but the proof of concept is established. The team has even developed a password-protection system so that a person’s private thoughts can’t be accidentally decoded: the device only activates when the user first imagines a specific passphrase.
This isn’t ESP in the paranormal sense, but it is, functionally, reading thoughts from a brain and converting them to communication. For people with severe paralysis, it represents something an esper was always imagined to be: someone whose mind can act on the world without their body.
Espers in Fiction
If you encountered the word “esper” in a game or anime, you’re far from alone. The term is a staple of Japanese media especially, appearing in series like “A Certain Scientific Railgun” (where espers are students with psychic powers ranked on a scale of 0 to 5), the Final Fantasy franchise (where espers are powerful magical beings that can be summoned), and “Mob Psycho 100” (centered on a teenager with psychokinetic abilities). In Western fiction, the X-Men are essentially espers by another name.
These fictional portrayals almost always draw on the same four-category framework from parapsychology, amplifying telepathy, clairvoyance, precognition, and psychokinesis into dramatic, visually spectacular abilities. The popularity of esper characters in fiction likely reinforces public fascination with ESP as a concept, keeping the idea culturally alive regardless of where the science lands.