How You Were Fooled

Are Bats Really Blind?

This episode dismantles the popular saying “blind as a bat,” revealing that bats are not blind at all. In fact, many bat species — especially fruit bats — have excellent eyesight, with night vision often superior to humans. Even insect-eating bats, which rely heavily on echolocation, still use their eyes to navigate, detect shapes, and sense light.
The myth arose because early scientists couldn’t detect the ultrasonic calls bats use for echolocation and assumed they navigated in darkness without vision. Over time, this misunderstanding became a catchy phrase, reinforced by folklore, cartoons, and Halloween imagery.
Modern research shows that bats combine echolocation and vision, giving them one of the most sophisticated navigation systems in the animal kingdom. Some species even have color vision and can see ultraviolet light.
The truth: bats aren’t blind at all — they’re multisensory experts. The myth survived simply because humans misunderstood how these remarkable creatures perceive the world.

Does Sugar Really Make Kids Hyperactive?

This episode challenges the widespread belief that sugar causes hyperactivity in children, a myth repeated by parents, teachers, and society for decades. Scientific research, including dozens of controlled studies, has shown no direct link between sugar consumption and increased activity, impulsivity, or attention problems.
One landmark experiment even tricked parents into believing their child had eaten sugar — and those parents perceived hyperactive behavior even though no sugar was given. This reveals that the myth is fueled more by expectation and perception than biology.
So why does the myth persist? Because sugary foods are usually eaten in high-energy environments — birthday parties, holidays, playdates — where kids are naturally more excited. Sugar gets blamed simply because it’s always present during chaotic, fun moments.
The myth also grew from 1970s diet fads and media-driven fears, which promoted sugar as a behavioral culprit without solid evidence.
The truth is clear: while excessive sugar can cause long-term physical health issues, it does not make kids hyperactive. The energy comes from the environment, not the dessert.
 
 
 

Does Cracking Your Knuckles Cause Arthritis?

This episode takes on the widespread belief that cracking your knuckles leads to arthritis, a warning repeated for generations. The truth, supported by decades of scientific research, is that knuckle cracking does NOT cause arthritis.
The popping sound people find alarming comes from cavitation — gas bubbles forming and collapsing inside the synovial fluid of the joint. It has nothing to do with bones grinding or cartilage being damaged.
One of the most famous investigations came from Dr. Donald Unger, who cracked the knuckles of his left hand daily for over 50 years while leaving his right hand untouched. After half a century, he found no difference between the two hands — no arthritis, no damage, no reduced function. More advanced studies using X-rays and long-term data have confirmed the same result.
The myth survived because the sound is unsettling, and people instinctively assume something harmful must be happening. While excessive or forceful cracking can cause temporary swelling or mild irritation, it does not damage joints or increase arthritis risk.
Ultimately, we were fooled not by evidence, but by a noise that seemed dangerous. The truth is simple: cracking your knuckles may annoy people around you, but it won’t cause arthritis.

Are Fingerprints Really Unique?

This episode investigates the long-standing belief that every human fingerprint is completely unique — a cornerstone of modern forensic science. While fingerprints are highly individual, the claim that no two are identical has never been scientifically proven.
The idea dates back to the late 19th century, when police forces adopted fingerprinting as a revolutionary identification tool. To strengthen its credibility, early criminologists declared that no two fingerprints could ever match — but this was based on assumption, not evidence. Over time, the statement hardened into “fact,” repeated in courts, textbooks, and media.
Modern science, however, paints a more nuanced picture. Fingerprints are shaped by both genetics and random conditions in the womb, making exact duplicates extremely unlikely — but not impossible. There’s no conclusive proof that identical prints don’t exist, simply because it’s impossible to compare every fingerprint on Earth.
Additionally, forensic errors have exposed flaws in fingerprint analysis. Examiners sometimes misidentify partial or unclear prints, leading to wrongful convictions — a sign that fingerprints, while powerful, aren’t infallible.
The truth? Fingerprints are extraordinarily distinctive, but not guaranteed to be unique. The myth survived because it provided certainty — something comforting for courts, juries, and society. In the end, we were fooled not by science, but by our desire for absolute truth in a world built on probabilities.

Do We Really Use Only 10% of Our Brains?

This episode breaks down the famous myth that humans use only 10% of their brains — an idea that’s been repeated in movies, motivational speeches, and self-help books for decades. The truth is that we use virtually 100% of our brains, just not all at once. Modern neuroscience shows that every part of the brain has a function, from regulating heartbeat and movement to processing emotions, memories, and imagination.
The myth likely began in the early 1900s, possibly from a misinterpretation of psychologist William James, who said humans use only a small portion of their potential — a philosophical idea, not a scientific one. Over time, writers and speakers simplified this into the “10%” claim. It thrived because it was inspiring — suggesting untapped potential and hidden genius within us all.
Brain scans (MRI and PET) have since proven the myth false. Every region of the brain is active throughout the day, and even small damage can cause serious impairments — clear evidence that no area is unused. Evolution wouldn’t waste energy maintaining idle tissue; our brains are efficient and constantly working.
Ultimately, we were fooled by a story that felt empowering. The idea that greatness lies in the “unused” 90% of our minds is poetic, but not real. The truth is even better: we already use the full capacity of our brains — and that’s what makes us extraordinary.

Do Carrots Really Improve Your Eyesight

This episode explores the famous belief that eating carrots improves eyesight — a “fact” most people learned in childhood. While carrots are rich in beta-carotene, which the body converts into vitamin A (an essential nutrient for maintaining normal vision), eating extra carrots does not give anyone superhuman sight. Once your body has enough vitamin A, additional amounts don’t make your vision any sharper.
The origin of this myth dates back to World War II, when the British Royal Air Force wanted to keep its new radar technology secret. To disguise the real reason their pilots could spot enemy planes at night, the government spread a cover story claiming that British pilots had exceptional night vision because they ate lots of carrots. The propaganda worked so well that it became accepted as scientific truth.
Over time, the myth spread globally through schools, advertisements, and everyday advice. It persisted because it was simple, harmless, and believable — combining real nutrition facts with an appealing message of self-improvement.
The truth? Carrots support normal eye health, but they don’t enhance it beyond natural limits. The idea that they improve night vision was clever wartime misinformation — proof that even a well-meaning lie can last for generations.

Are Bulls Really Angered by the Color Red?

This episode uncovers the truth behind the long-standing myth that bulls become enraged when they see the color red. Contrary to popular belief, bulls are color-blind to red and green — they are dichromatic animals that can only perceive shades of blue and yellow. The real trigger for a bull’s charge in a bullfight is movement, not color.
The famous red cape, or muleta, used by matadors isn’t meant to provoke the bull at all — it’s meant for the audience. The color red symbolizes passion and danger while conveniently hiding the blood that appears during the fight. The myth took hold because of centuries of artistic symbolism, storytelling, and repetition. Humans associated the color red with anger, and over time, projected that idea onto the animal.
Scientific experiments have confirmed that bulls charge equally at moving objects of any color — red, blue, yellow, or white. They ignore motionless ones entirely. This proves that motion, not hue, provokes the bull’s aggression.
Ultimately, the story of the “angry bull and the red cape” reveals more about human psychology than animal behavior. We were fooled by symbolism, tradition, and our tendency to see emotions in animals that don’t think the way we do. The red cape, it turns out, was always for us — not for the bull.

Does Shaving Really Make Hair Grow Back Thicker

This episode debunks the widespread belief that shaving causes hair to grow back thicker, darker, or faster. The truth is clear: shaving does not change the structure, speed, or color of hair growth. It only appears thicker because shaving cuts the hair straight across, leaving a blunt, flat tip instead of its natural soft, tapered end. That blunt regrowth feels rougher and looks darker — creating an illusion of thicker hair.
The myth spread due to visual misinterpretation, old flawed studies, and generations of repeated advice, not science. In reality, hormones and genetics — not razors — control hair growth. If shaving truly made hair stronger, bald men would shave to cure hair loss, which clearly doesn’t work.
The takeaway: Your razor isn’t rewriting your DNA. Shaving doesn’t make hair thicker — it just changes how it looks and feels temporarily.
 
 
 

Humans Only Have Five Senses — Or Do We

This episode debunks the common belief that humans have only five senses — sight, hearing, smell, taste, and touch. While this idea is widely taught in childhood, it actually comes from Aristotle, not modern science. He guessed based on observation, and his framework became tradition rather than scientific fact.

Leeches and Medieval Medicine

This episode examines the enduring myth that medieval doctors used leeches for everything, portraying them as ignorant and superstitious. In reality, leeches were part of a wider medical practice called bloodletting, rooted in the ancient theory of balancing the body’s four humors. While leeches were common, they weren’t a universal cure — medieval physicians also prescribed herbs, diet, baths, rest, and even surgeries.
The image of leeches stuck because it was memorable, dramatic, and symbolic of “backward” medicine, reinforced by satire, art, and the narrative of modern progress. By the 19th century, bloodletting was mocked as barbaric, and the leech became a shorthand for medical ignorance.
However, the twist is that leeches aren’t entirely useless. Modern medicine still uses them in microsurgery and reconstructive procedures, since their saliva contains hirudin, a powerful anticoagulant that helps restore blood flow.
The episode highlights how the myth oversimplifies the past. Medieval medicine was flawed but not completely foolish, and even its strangest practices sometimes contained a kernel of truth. The persistence of the leech image says more about how we like to imagine history than about what actually happened.