In 36 B.C.E., Roman statesman Marcus Varro wrote about germs, describing "minute creatures which cannot be seen by the eyes, which...enter the body through the mouth and nose and there cause serious diseases." The germ theory of disease would not be accepted widely for another 1,900 years.
2. The prevailing theory behind why humans like music is that we learn patterns and regularities within music, and we unconsciously predict what will come next. When we are right, our brain gives us a dopamine rush. Thus the constant dance between expectation and outcome is pleasurable to us.
3. The snake detection theory states that humans are remarkably good at noticing snakes, even when camouflaged or when we only get a brief glimpse of them.
4. The stoned ape theory is a controversial theory from Terence McKenna which states that a lot of our advanced human evolution came as a result of the ingestion of magic mushrooms a.k.a. psilocybin mushrooms by our primate ancestors.
5. Time seems to speed up as we get older because each year we live is a smaller percentage of the total amount of time we have been alive. This theory has been named proportional theory.
In 1736, mathematician Leonhard Euler was trying to find a way to cross every single one of the seven bridges of Königsberg exactly once. He realized that this was, in fact, impossible and based on that created a new area of mathematics called Graph Theory.
7. Ancient Greek historian Polybius came up with a cyclical theory of government (anacyclosis), which proposes that governments start off as monarchies and end finally with ochlocracy when a democracy degenerates into chaos and mob-rule. Then the cycle resets itself.
8. The Type A/B Personality Theory was actually invented by the cigarette industry in the 1950s to prove coronary heart disease and cancer were risks related to high-stress personality types instead of tobacco use.
9. Three physicists flew around the world twice in 1971 with synced atomic clocks to test out the time dilation theory. Upon meeting up, they found that all 3 of the clocks disagreed with each other.
10. If the atom was the size of the observable universe, then the theoretical ‘string’ in string theory would be the size of a tree.
11Sahara pump theory
The Sahara pump theory states that in about 10,000 years from now, the change in the orientation of the rotational axis of Earth's poles will move the North African Monsoon far enough north to convert the Sahara back into a tropical climate, as it was during 5,000–10,000 years ago.
12. One theory on why we are ticklish is that it serves as a mechanism for developing combat skills. Most often practiced from parent to child, tickling activates vulnerable areas on the body that develop a defensive reaction while producing laughter that encourages the 'attacker' to continue.
13. Beer-before-bread theory suggests that early humans were first inspired to settle down and adopt agriculture in order to produce beer, rather than bread.
14. Narcotizing dysfunction theory suggests that as mass media inundates people on a particular issue, they become apathetic to it, substituting knowledge for action. Obsessively following news tricks your brain that you are doing something about it, when in reality you are doing nothing.
15. The theory of an infinite universe was first proposed by a Greek philosopher named Archytas of Tarentum around 400 B.C., reasoning that even if he did reach the end of the universe he would still be able to extend his staff beyond the boundary.
Nixon's strategy during Vietnam was called the Madman Theory and it focused on making the enemy think Nixon was insane and if provoked would act irrationally.
17. Hitler's chief architect, Albert Speer, was an adherent of the "theory of ruin value." His architectural goal was constructing buildings that would later collapse into aesthetically-pleasing ruins over the course of thousands of years.
18. Black Swan Theory states that rare catastrophic events which are beyond the realm of normal expectation or predictability (but later inappropriately rationalized by hindsight) play a vastly larger role in the course of history than any predictable or foreseeable occurrence.
19. The intense world theory suggests that Autistic people do not lack empathy/emotion. They shut down because they are overloaded by emotions due to hypersensitivity and are not able to express empathy/emotion like other people because of that. Essentially, Autistic people feel too much.
20. Peter’s Principle states that companies promote people into management on account of performance rather than ability, resulting in incompetent managers and inefficiency.
21Broken Windows Theory
The "Broken Windows Theory" states that maintaining and monitoring urban areas to prevent small crimes, such as vandalism, helps to create an atmosphere of order and lawfulness - thereby preventing more serious crimes from happening.
22. Julian Jaynes' "bicameral mind theory" suggests that ancient humans were not self-aware and that the right hemisphere communicated with the left via auditory hallucinations. These voices may have been interpreted as "Gods" by early humans.
23. The theory of inoculation has its uses in politics and advertising. Basically, introducing a weak form of an argument can easily be thwarted in order to prepare the audience to disregard a stronger, full-fledged form of the argument from an opposing party.
24. There is a theory that the chronic vocal injuries suffered by today's vocalists are directly caused by the "sing from your diaphragm" methods introduced in the 1800s.
25. The Aquatic Ape Theory suggests that early hominids lived in the water part of the time and thus explains our hairless bodies (streamlined for swimming), our upright two-legged walking (made wading easier), and our layers of subcutaneous fat, which made us better insulated in water (similar to whale blubber).