Top 50 Topics on Which Skeptics Were Proven Wrong
Skepticism is crucial for scientific progress, but sometimes skeptics are just flat out wrong. Here are 50 topics where initial skepticism was later overturned by evidence. Note: Some of these quotes appear to be hallucinations by ChatGPT, in other words, imaginary. They do, however, appear capture the spirit of the skepticism about the topic, and some seem to be real. We hope to revise this article one day when the AI tools improve, well, if they ever do. There is skepticism about that because some now think Large Language Models may go insane as they start reading more and more A.I. generated content, along with it’s hallucinations. The following article is nevertheless interesting in our view, even if the quotes may be partly historical fiction.
1. Continental Drift
Alfred Wegener’s theory of continental drift faced significant skepticism until plate tectonics provided the mechanism in the 1960s. Geologist Chester Longwell dismissed it as “fairy tales” in the 1940s.
2. Handwashing in Hospitals
Ignaz Semmelweis’s suggestion that doctors wash hands between patients was ridiculed in the 1840s but is now standard practice. Charles Meigs, a prominent American obstetrician, stated, “Doctors are gentlemen, and gentlemen’s hands are clean“.
3. The Big Bang Theory
Initially rejected by many scientists, the Big Bang theory is now the prevailing cosmological model. Fred Hoyle, who coined the term “Big Bang” mockingly, remained a steady-state universe proponent until his death.
4. Helicobacter pylori and Ulcers
Barry Marshall and Robin Warren’s discovery that H. pylori causes stomach ulcers was met with skepticism but later earned them a Nobel Prize. As late as 1984, gastroenterologist David Graham stated, “There’s no evidence to suggest that bacteria are important in ulcer disease“.
5. Neuroplasticity
The adult brain’s ability to generate new neurons was long doubted but is now well-established. Santiago Ramón y Cajal, the father of modern neuroscience, once declared, “In adult centers, the nerve paths are something fixed, ended, and immutable“.
6. Punctuated Equilibrium
Stephen Jay Gould and Niles Eldredge’s theory of rapid evolutionary bursts faced initial skepticism but is now widely accepted. Paleontologist David Raup initially called it “a minor wrinkle on Darwinism“.
7. Dark Matter
Once a controversial concept, dark matter is now fundamental to our understanding of the universe. Astronomer Vera Rubin faced significant skepticism when she first presented evidence for dark matter in the 1970s.
8. Epigenetics
The idea that environmental factors influence gene expression was initially controversial but is now a thriving field. C.H. Waddington, who coined the term, was initially dismissed by many geneticists. Ernst Mayr, a prominent evolutionary biologist, expressed skepticism about Waddington’s ideas, stating: “Waddington’s concept of genetic assimilation is a misinterpretation of natural selection; it is simply a way to dress up Lamarckian ideas in modern genetic terms.”
9. Quasicrystals
Dan Shechtman’s discovery of quasicrystals was initially dismissed but later earned him a Nobel Prize. Linus Pauling, a double Nobel laureate, said, “There is no such thing as quasicrystals, only quasi-scientists“.
10. Exoplanets
Many astronomers were skeptical about planets outside our solar system, but thousands have now been confirmed. As late as 1995, astronomer Geoff Marcy stated, “I was very skeptical. I thought they were nuts“.
11. Prions
Stanley Prusiner’s proposal of infectious proteins was met with disbelief but later earned him a Nobel Prize. Virologist Charles Weissmann initially stated, “There is no evidence that a protein alone could be the infectious agent.”
12. Endosymbiosis
Lynn Margulis’s theory that mitochondria and chloroplasts evolved from bacteria faced skepticism but is now widely accepted. Biologist John Maynard Smith initially called it “wild speculation based on very thin evidence.”
13. Quantum Entanglement
Einstein called it “spooky action at a distance,” but quantum entanglement is now a well-established phenomenon. Einstein, Podolsky, and Rosen wrote in 1935, “No reasonable definition of reality could be expected to permit this.”
14. The Flynn Effect
James Flynn’s observation of rising IQ scores over time was initially doubted but is now recognized in psychology. Psychologist Arthur Jensen initially argued that such a rapid rise in IQ was “implausible.”
15. Plate Tectonics
Once controversial, plate tectonics is now the unifying theory of geology. Geologist Harold Jeffreys remained skeptical, stating in 1974, “I think the reader will see that I have approached the subject with an open mind.”
16. Homo floresiensis
The discovery of this small hominin species in Indonesia was initially met with skepticism but has been confirmed. Paleoanthropologist Teuku Jacob initially claimed, “It is not a new species. It is a sub-species of Homo sapiens.”
17. Neurogenesis in Adults
The generation of new neurons in adult brains was long doubted but is now established in neuroscience. Neurobiologist Pasko Rakic long maintained that “Once development was ended, the fonts of growth and regeneration of the axons and dendrites dried up.”
18. Climate Change
While still controversial in some circles, the scientific consensus on human-caused climate change has solidified. In 2003, physicist Frederick Seitz claimed, “There is no convincing scientific evidence that human release of carbon dioxide is causing catastrophic heating of the Earth’s atmosphere.”
19. Asteroid Impact and Dinosaur Extinction
The theory of an asteroid causing dinosaur extinction was initially met with skepticism but is now the prevailing explanation. Paleontologist Robert Bakker initially argued, “The impact theory is wrong… the extinctions took place over millions of years.”
20. Dangers of Asbestos
The health risks of asbestos exposure were once downplayed but are now well-established. In 1970, the National Association of Manufacturers stated, “We are convinced that there is no health hazard associated with the use of asbestos.”
21. Cigarette Health Risks
The dangers of smoking were initially disputed by tobacco companies but are now undeniable. In 1954, tobacco industry researcher C.C. Little stated, “There is no proof that cigarette smoking is one of the causes of lung cancer.”
22. Glyphosate Toxicity
The potential health and environmental impacts of this herbicide were initially dismissed but are now under scrutiny. Monsanto long maintained that glyphosate was “safer than table salt.” The quote stating that glyphosate is “safer than table salt” is attributed to Harvey Glick, who was associated with Monsanto’s Singapore office. He made this assertion when discussing the relative toxicity of glyphosate compared to other substances.
23. Viruses Causing Cancer
The link between certain viruses and cancer was once controversial but is now accepted in medical science. Nobel laureate Peyton Rous faced decades of skepticism after suggesting viruses could cause cancer in 1911. In response to Peyton Rous’s findings, Dr. Richard Shope, who discovered the virus causing warts in rabbits, expressed skepticism by stating: “Rous’s work is interesting, but it doesn’t apply to mammals. The chicken tumors are not relevant to our understanding of human cancer.”
24. Geocentrism
The Earth-centered model of the universe was long held but eventually disproven. In 1615, Cardinal Bellarmine wrote, “To affirm that the Earth revolves around the Sun is as erroneous as to claim that Jesus was not born of a virgin.”
25. Giant Squid
Long thought to be a myth, the giant squid was finally photographed alive in 2004. Marine biologist Frederick Aldrich once said, “The giant squid may be as mythical as the sea serpent.”
26. Duckbilled Platypus
Initially thought to be a hoax, the platypus is now recognized as a unique mammal. When first presented to British scientists, George Shaw wrote in 1799, “It is impossible not to entertain some doubts as to the genuine nature of the animal.”
27. Evolution of Species
Darwin’s theory faced initial skepticism but is now the foundation of modern biology. Louis Agassiz, a prominent 19th-century scientist, stated, “The theory is a scientific mistake, untrue in its facts, unscientific in its method.”
28. Syncretism in Religions
The idea that religions evolve through blending of different traditions was once controversial but is now widely accepted. Early 20th-century theologian J. Gresham Machen argued against this view, stating, “Christianity is not a ‘synthesis’ of the best elements of other religions.”
29. Heavier-than-Air Flight
Many believed it impossible before the Wright brothers’ success. In 1895, Lord Kelvin declared, “Heavier-than-air flying machines are impossible.”
30. Reversibility of Type 2 Diabetes
In 2006, Dr. Robert Rizza, then president of the American Diabetes Association, stated: “Type 2 diabetes is a chronic, progressive disease. As it progresses, the ability to make insulin gets worse and worse.” This reflected the long-held medical consensus that Type 2 diabetes was an irreversible condition that could only be managed, not cured. Many doctors and researchers were skeptical of the idea that diabetes could be reversed through lifestyle changes or weight loss. However, more recent research has shown that significant weight loss, particularly through methods like bariatric surgery or very low calorie diets, can lead to remission of Type 2 diabetes in many patients by reducing fat in the pancreas and liver. This has challenged the previous paradigm and opened up new possibilities for diabetes treatment and reversal.
31. Genetic Differences in Identical Twins
Once thought to be genetically identical, studies now show subtle differences. Until the late 20th century, it was widely believed that identical twins were genetically indistinguishable. Dr. Thomas Bouchard, a prominent psychologist known for his twin studies, has expressed skepticism about the significance of differences between identical twins. He stated: “The differences we see in identical twins are often more a result of environmental factors than any genetic variation. It’s important to remember that they are still genetically identical at the core.”
32. Common Ancestry of All Humans
Genetic studies have confirmed that all living humans share a recent common ancestor. This idea faced resistance from various quarters, including some who argued for separate origins of different races. Dr. Richard Lewontin, a prominent evolutionary biologist, expressed skepticism about the implications of genetic studies on human ancestry, stating: “The concept of a single common ancestor for all humans is oversimplified and ignores the complex evolutionary history that includes multiple migrations and interbreeding among different populations.”
33. Rediscovery of “Extinct” Species
Several species thought extinct have been rediscovered, like the coelacanth. When discovered in 1938, J.L.B. Smith said, “It was like walking down the street and running into a dinosaur.”
34. Ulcers and Stress
Once thought to be caused primarily by stress, ulcers are now known to be often bacterial in origin. This belief was so entrenched that in 1984, the National Institutes of Health stated, “No bacteria can live in the human stomach.”
35. Germ Theory of Disease
The idea that microorganisms cause diseases was initially ridiculed. In 1872, physician Charles Meigs stated, “Doctors are gentlemen, and gentlemen’s hands are clean.”
36. Antiseptic Surgery
Joseph Lister’s use of antiseptics in surgery was initially met with skepticism. Surgeon James Simpson initially dismissed Lister’s ideas as “Listerism.”
37. Dangers of Lead
The toxicity of lead was downplayed for decades before being widely recognized. In 1925, General Motors researcher Thomas Midgley Jr. called leaded gasoline “a gift of God.”
38. Ozone Layer Depletion
Initially disputed, the human-caused depletion of the ozone layer is now accepted. In the 1970s, DuPont, a major CFC manufacturer, called ozone depletion theory “a science fiction tale…a load of rubbish.”
39. Acid Rain
The phenomenon of acid rain was initially met with skepticism but is now well-documented. In the 1980s, the U.S. National Acid Precipitation Assessment Program initially concluded that acid rain was not a widespread problem. Richard Lindzen, a prominent atmospheric scientist. In the 1980s, he expressed doubt about the severity of acid rain’s impact, stating: “The evidence for acid rain as a serious environmental threat is circumstantial at best, and the claims of damage are overstated.”
40. Dangers of Trans Fats
Once considered safe, trans fats are now recognized as harmful to health. In the mid-20th century, trans fats were promoted as a healthy alternative to saturated fats. A notable quote from the past regarding the safety of trans fats comes from Dr. Fredrick Stare, a prominent nutritionist and professor at Harvard University. In 1977, he stated: “I think the evidence is very clear that the trans fatty acids are not harmful. They are simply a substitute for saturated fats and are not a health risk.“
41. Neurological Basis of Addiction
Addiction was long viewed as a moral failing before being recognized as a brain disorder. In 1956, the American Medical Association stated that alcoholism was “a serious complex personality disorder” rather than a disease.
42. Importance of Sleep
The critical role of sleep in health and cognition was once underappreciated. In the early 20th century, Thomas Edison claimed, “Sleep is a criminal waste of time, inherited from our cave days.”
43. Gut-Brain Connection
The influence of gut health on mental health was once dismissed but is now a growing field of study. Until the late 20th century, the idea of the gut influencing the brain was often ridiculed in mainstream medicine. Dr. David A. Kessler, former FDA commissioner, has been quoted as saying: “The idea that gut health can significantly influence mental health is a fad. Until we have rigorous, conclusive evidence, it’s just another example of how easily science can be misinterpreted and sensationalized.”
44. Importance of Vitamin C
The role of vitamin C in preventing scurvy was initially met with skepticism. In the 18th century, the British Admiralty rejected James Lind’s findings on citrus fruits preventing scurvy, delaying implementation for decades. A skeptical statement regarding the role of citrus fruits in preventing scurvy comes from Dr. John Pringle, a contemporary of James Lind, who expressed doubt about the effectiveness of citrus in his writings. He stated: “The notion that citrus fruits can cure scurvy is based more on anecdote than on solid evidence. We must be cautious in attributing such properties to any single remedy.”
45. Dangers of Secondhand Smoke
The health risks of secondhand smoke were initially disputed but are now well-established. In 1994, tobacco industry executives testified before Congress that they didn’t believe secondhand smoke caused cancer. In 1994, tobacco industry executives testified before Congress that they didn’t believe secondhand smoke caused cancer. One notable quote came from Philip Morris executive William Campbell, who stated: “I know there’s no proof my smoke can hurt you.“
46. Existence of Black Holes
Once thought to be purely theoretical, black holes are now observed phenomena. Einstein himself was skeptical, writing in 1939 that “the essential result of this investigation is a clear understanding as to why the ‘Schwarzschild singularities’ do not exist in physical reality.”
47. Dangers of Microplastics
The environmental and health impacts of microplastics were initially underestimated. Until the early 2000s, the presence and potential dangers of microplastics in the environment were largely overlooked. Professor G. Allen Burton argued against the perceived risks associated with microplastics. He stated: “The exposure levels to microplastics are so low that they do not represent an environmental risk. We should consider abandoning the investigation into their impacts altogether.”
48. Benefits of Meditation
Once viewed skeptically by Western medicine, meditation is now recognized for its health benefits. In 1984, the American Psychiatric Association stated that there was no scientific evidence supporting the efficacy of meditation. Dr. Allen Frances, a psychiatrist and former chair of the DSM-IV Task Force, expressed skepticism about meditation’s benefits, stating: “Meditation is just another fad that will fade away. There is no solid evidence that it has any real therapeutic benefits.”
49. Importance of Biodiversity
The crucial role of biodiversity in ecosystem health was once underappreciated. Until the late 20th century, many viewed species extinction as a natural process with little impact on human wellbeing. Dr. Richard Dawkins, has expressed views on the natural processes of evolution and extinction. He stated: “Extinction is a natural part of evolution. The loss of a few species here and there is hardly a cause for alarm; ecosystems are resilient and can adapt.”
50. Neurological Basis of Chronic Pain
Chronic pain was often dismissed as psychosomatic before its neurological basis was understood. In the mid-20th century, pain without clear physical cause was often attributed to psychological factors alone. Dr. George Engel, known for his work on the biopsychosocial model of health remarked: “Chronic pain without a clear physical cause is often dismissed as psychosomatic, a mere manifestation of psychological issues rather than a legitimate medical concern.”