A Boise State University review on the nature and determinants of scientific beliefs shows that once people adopt a simple, intuitive explanation, they often keep believing it even after it’s been disproven. This is because the myth feels easier to remember and explain than the correct version.
Throughout history, humans have made countless discoveries, but they’ve also held onto some completely misguided beliefs. These misconceptions, often rooted in limited knowledge or superstition, have shaped cultures and societies for centuries.
As science advanced and more knowledge was uncovered, many of these beliefs were debunked. Here are 12 things people once believed that turned out to be completely wrong.
The Earth is Flat
A historical overview from the Library of Congress on ancient cosmology shows that many early cultures pictured Earth as a flat disk, and that Greek philosophers such as Pythagoras and Aristotle later helped shift thinking toward a spherical Earth using observations like lunar eclipses and changing star positions.
While early explorers faced dangers navigating the “edges” of the Earth, modern science has fully confirmed that our planet is round. Satellites and space missions have provided undeniable proof of this.
The Sun Revolves Around the Earth
For centuries before Copernicus, the dominant view in Europe and the Mediterranean was the geocentric model, which placed Earth at the center of the universe with the sun, moon, and planets orbiting it. This belief was reinforced by major religious traditions and philosophical systems, which treated Earth as a fixed, central creation rather than a planet moving around the sun.
It wasn’t until the work of Galileo Galilei and Johannes Kepler that the idea of a heliocentric solar system, in which the Earth revolves around the sun, gained widespread acceptance. This discovery revolutionized our understanding of the cosmos.
Spontaneous Generation
Many once believed in spontaneous generation, thinking that maggots came from meat and that frogs came from muddy water. Later experiments in 1668 and 1861 by Francesco Redi and Louis Pasteur proved life comes from existing life, overturning the old belief.
It wasn’t until the 19th century, with experiments by Louis Pasteur and others, that the theory of spontaneous generation was disproved. Pasteur’s work helped establish the foundation of germ theory and modern microbiology.
Diseases are Caused by Bad Air (Miasma Theory)
Before germ theory, many people believed diseases like cholera and plague came from “miasma,” or bad air rising from waste, swamps, and rotting material, rather than from microbes. This idea shaped city design, sanitation laws, and even quarantine practices for decades.
It wasn’t until John Snow and Louis Pasteur contributed to the development of germ theory that people understood how diseases were spread by bacteria and viruses, not by air.
Bloodletting Cures Illness
Bloodletting was used as a standard treatment for at least 3000 years and only began to be widely discredited in the late 19th century. Historical records show that, at its peak in the 1830s, doctors in France used an estimated 35 million leeches per year for bloodletting, illustrating how deeply this mistaken practice was embedded in medical care.
However, as medical knowledge advanced, it became clear that bloodletting did more harm than good, especially in the case of George Washington, who died after extensive bloodletting. Modern medicine now understands that proper treatment involves more specific, evidence-based approaches.
You Only Use 10% of Your Brain
The 10% brain myth has been around for more than a century and is still widely believed, with recent polls showing that well over half of people agree with it. Modern brain imaging, however, demonstrates that almost all brain regions show activity over the course of a typical day, even during rest or sleep, meaning far more than 10% is in use.
In reality, neuroimaging techniques have shown that virtually all parts of the brain have a function, and that even during sleep, the brain remains highly active. This myth has been debunked through numerous studies on brain activity.
The Earth is Only 6,000 Years Old
An influential 17th‑century chronology by Archbishop James Ussher dated the creation of the world to 4004 BC, reinforcing the belief that Earth was only about 6,000 years old and shaping popular views of Earth’s age for generations.
Through the study of rock layers and fossils, scientists now understand that Earth is about 4.5 billion years old, much older than previously thought.
Also on MSN: 16 Myths People Still Believe About Native Americans
The Human Body is a Closed System
Early physiologists described the body as almost a sealed vessel, without a clear understanding of how gases and materials moved in and out. Work by scientists such as Antoine Lavoisier in the late 1700s helped overturn this, showing that the body constantly exchanges oxygen and carbon dioxide with the environment through respiration and metabolism.
However, modern biology has shown that the body constantly interacts with its environment through breathing, digestion, and the immune system. The exchange of gases, nutrients, and waste proves that the body is much more dynamic than once believed.
The Soul Resides in the Heart
In many early civilizations, the heart was literally treated as the center of mind, soul, and emotion, not just a metaphor. Ancient Egyptian and Greek traditions, for example, saw the heart as the organ that housed wisdom, character, feelings, and even moral judgment, while the brain was viewed as secondary or largely unimportant.
Scientific research, however, has shown that the brain is responsible for emotions, thoughts, and behavior. The heart’s role is to circulate blood, not to control the mind or soul.
The Tooth Fairy is Real
As a fun and cherished tradition, the Tooth Fairy was once believed to be a magical creature who exchanged a lost tooth for money or gifts. This childhood myth was widespread across many cultures.
Eventually, children grow up and learn that the Tooth Fairy is not real, but part of a broader tradition of folklore and imaginative storytelling passed down through generations.
Washing Your Hair With Soap is Safe
Many once treated regular bar soap as “good enough” for hair, not realizing how stripping it can be. The men’s shampoo market, now worth about 24.5 billion dollars, has shifted toward gentler, sulfate‑free formulas to protect scalp health.
Today, specialized shampoos and conditioners are formulated to cleanse hair while preserving moisture and strength. This evolution in hair care products has become an essential part of modern grooming.
Slaves built the Pyramids
For years, popular culture claimed that enslaved people, often imagined as foreign or Jewish slaves, built the Great Pyramids of Giza. 1990s-2000s excavations uncovered workers’ villages and mud-brick tombs showing organized Egyptian laborers housed, fed meat and bread, and buried nearby, treatment unfit for slaves.
Archaeological evidence suggests that these workers were well-fed, housed, and honored for their contributions, challenging the traditional view of pyramid construction.
Key Takeaway
Throughout history, people have held many beliefs that, though widely accepted at the time, were later proven wrong. Whether it was the belief in a flat Earth or the idea that diseases were caused by bad air, misconceptions shaped human understanding for centuries.
Science, curiosity, and new discoveries continue to challenge old ideas, teaching us that knowledge evolves, and what we believe today may be completely different tomorrow.
Disclaimer – This list is solely the author’s opinion based on research and publicly available information. It is not intended to be professional advice.
Disclosure: This article was developed with the assistance of AI and was subsequently reviewed, revised, and approved by our editorial team.
25 Ways to Lose Weight Without Exercise
25 Ways to Lose Weight Without Exercise
I’m here to let you know that losing weight without becoming a fitness enthusiast is definitely achievable. You won’t need to sweat excessively, just a little bit (after all, we all have to walk to the fridge, don’t we?). Here are 25 ways to lose weight without exercising.
