19 High School Lessons Debunked by Science

One of the best things about science is its ability to evolve and learn, often changing or clarifying facts when new insights emerge. However, this can make some of our earlier scientific teachings obsolete or inaccurate. This article explores 19 science ‘facts’ from high school that have since been entirely debunked or significantly updated.

The Tongue Taste Map

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Chemosensory scientists debunked this myth several years ago, thought to have originated from an early 20th-century misinterpretation of data. The Smithsonian Institute writes, “The ability to taste sweet, salty, sour, and bitter isn’t sectioned off to different parts of the tongue. The receptors that pick up these tastes are actually distributed all over.”

Humans Only Use 10% of Their Brains

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Neuroscientists have shown through imaging techniques (like fMRI and PET scans) that almost every part of the brain has a function; they’re just active at different times. The Association for Psychological Science confirms that our brains are constantly active, although activity levels are not at 100% in every region at all times—which would actually be dangerous!

Evolution Is Just a Theory

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Evolution may have been just a theory when it was proposed by Charles Darwin and Alfred Wallace in 1858, but they and others already had supporting evidence. The Harvard Museum of Natural History reports that, since then, reliable and indisputable scientific study has made evolution a scientific fact, proven by genetics, paleontology, anatomy, and embryology.

Deoxygenated Blood is Blue

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Medical News Today asserts that blood in the body is red no matter how much oxygen it carries, although the shade of red may vary slightly (oxygenated blood is more vibrant). The myth likely stems from the fact that our veins appear bluish through the skin (an optical illusion) and the fact that veinal blood is depicted as blue in educational diagrams.

Humans Have Five Senses

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Many of us were taught that we possess five senses—sight, hearing, smell, touch, and taste—but this is a gross oversimplification. The BBC writes that neuroscientists think human sensory perception is complex and that other abilities (like balance, thermoreception, spatial awareness, and feeling pain) may be just a few of our additional sensory capabilities.

Lightning Never Strikes the Same Place Twice

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This myth suggests a randomness to lightning that doesn’t exist. In reality, electricity follows the path of least resistance—whether that’s a path it’s previously followed or not. Tall, isolated, or pointed objects are most likely to be hit; for example, the Empire State Building is struck by lightning approximately 25 times every year!

Humans Evolved from Chimpanzees

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No, that’s not how evolution works—it’s not a line of slightly different species changing from one to the next but a complicated web of diversification with multiple branches and many ‘dead ends.’ The American Museum of Natural History writes that humans and chimps share 98.8% of their DNA because they share a common ancestor that gave rise to the two forms around 6–7 million years ago.

Dinosaurs Were All Giants

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These prehistoric reptiles weren’t uniformly large, but they displayed a huge variety of different forms. Although some dinosaurs, like the herbivorous sauropods, reached immense sizes, many dinosaurs were much smaller, some even the size of a chicken! This diversity is one of the reasons their ancestors (the birds) still exist in modern times.

The Sahara Desert Is Expanding due to Global Warming

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While not categorically untrue, this statement disregards the list of inter-playing factors that impact desertification and desert boundaries. Iberdrola reports that deforestation is the leading cause of desert expansion worldwide, whereas land management, overgrazing, and natural climate variability also play significant roles.

Goldfish Have a Three-Second Memory

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This myth helps perpetuate animal neglect by insinuating that goldfish don’t mind being kept in small, uninteresting bowls of water. Live Science reports that goldfish can remember things for months, highlighted by experiments that show they can recognize their caregivers, navigate mazes, and respond to repetitive cues, even after five months have passed.

Humans and Dinosaurs Coexisted

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If you remember science textbooks with prehistoric humans fighting off dinosaurs, you’ve been greatly misled. Scientific methods like radiometric dating place the extinction of the dinosaurs about 65 million years before the appearance of modern humans, making such a scene entirely impossible.

Ostriches Stick Their Heads in the Sand When Threatened

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McGill University confirms there is no evidence that ostriches stick their heads into sand for any reason. The misconception probably originates from the behavior of adult birds tending a sunken nest, as they frequently use their beak to rotate the clutch of eggs for even temperature distribution—which can make it look like they have their heads buried in the ground!

Sugar Causes Hyperactivity in Children

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While parents may like to use this as an excuse to withhold sweet treats, numerous scientific studies have found no link between hyperactivity and dietary sugar. The myth may have been ‘supported’ by coincidence—children often get excited at birthday parties and special occasions when sweet foods like cake, candies, and ice cream are readily available.

A Duck’s Quack Doesn’t Echo

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Like any sound, a duck’s quack produces sound waves and can produce an echo under the right conditions. The Guardian reports that the misconception arises from the quack’s acoustic properties, which make its echo harder for the human ear to distinguish, particularly in certain environments.

Shaving Makes Hair Grow Thicker

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The idea that shaving hair on the body makes it grow back thicker, darker, or faster is a common misconception based on ‘evidence,’ which is merely an illusion. When hair regrows after shaving, it feels coarser because the tapered end has been removed, making it blunter. It may also appear darker initially because newly emerged hair hasn’t yet been faded by sunlight.

Chameleons Change Color for Camouflage

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While chameleons do change color, the primary reason is not camouflage. WIRED writes, “It’s a common misperception that they do this to camouflage themselves against a background. In fact, chameleons mostly change color to regulate their temperatures or to signal their intentions to other chameleons.” They may be signaling fear, aggression, or a readiness to mate.

Eating at Night Makes You Fat

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There is a complex relationship between diet, metabolism, and weight management, but merely eating before bed doesn’t guarantee weight gain. Caloric intake and expenditure are like a bank balance—if you put more in than you take out (via metabolism and exercise), you will gain weight, and that applies no matter what time of day you consume those calories.

Humans Came to the Americas Via the Bering Land Bridge

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Many outdated textbooks taught students that prehistoric man first reached the Americas 13,000 years ago by crossing the Bering Land Bridge. However, archaeologists have discovered evidence of stone tools and ash in a Mexican cave dating back 30,000 years—long before the Bering Bridge existed.

Drinking Alcohol Warms Your Body

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Alcohol causes vasodilation—the opening up of blood vessels—so your skin often feels warmer after you’ve indulged. This has led to the myth that alcohol helps warm the body when, in fact, it does the opposite by moving more blood closer to the skin’s surface, where it’s more easily cooled by the external environment.

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18 Misunderstood Acts The Bible Says Aren’t Actually Sins

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People tend to assume that the Bible condemns a wide array of behaviors, but the reality might surprise you. Here, we zoom in on 18 so-called “sins” that may not be as bad as we thought.

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18 Things You’re Far Too Old To Be Doing Anymore

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As we grow older, it’s a great time to reevaluate our choices and habits. In this article, we’ll explore 18 things you may still be doing even though you may be too old.

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18 Things That Become Intolerable as You Get Older

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As people age, they sometimes don’t find as much joy in things as they used to. An internet survey recently asked, “What are you starting to dislike more as you get older?” Here are the top 19 responses.

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The Boomers Called It: 19 Stupid Trends That Backfired

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Sometimes, we get carried away with trends that we think are cool at the time, only to realize later how utterly ridiculous they were. Join us as we take a cringe-worthy trip down memory lane and explore 19 stupid trends that backfired. Prepare for some facepalms!

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