15 Weird Things We Used to Believe About the Brain

As scientific research has progressed, a surprising amount of mistaken information about the brain has stayed in our collective consciousness. For example, have you ever heard someone suggest that they don’t excel at math because they are ‘left-brained’? It turns out that the left brain/right brain division is completely false. So are many other things we think we know about the magnificent organ that powers our central nervous system.

Check out the list of now-debunked theories about the brain here, and make sure your knowledge is up to date:

We only use 10% of our brain

This theory was spouted by motivational speakers everywhere for years, with the idea that if we were told that we only used 10% of our brains every day, it would give us a new goal to strive towards.

However, it turns out we actually use up every little bit of our brain with our daily tasks. There are no superfluous areas up there! Injury to even a millimeter of our brain can cause irreparable damage. Perhaps the person who made up this fact was referring to the endless untapped potential of our minds, rather than speculating about physical space in the brain.


Getting hit on the head will cause amnesia

This is a trope of terrible movies all around the world: the damsel in distress is knocked on the head, causing her to forget her pining fiancé. Another strategic knock sets her to rights almost immediately. This couldn’t be farther from the truth.

There are two different types of amnesia: anterograde, which is the inability to form new memories, and retrograde, which inhibits our recall of memories. Neither of them is caused by a mere knock on the head. It takes a massive brain injury, or a disease like Alzheimer’s to cause amnesia.

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We know what will make us happy

It is almost impossible for scientists to predict how happy something will make you. The things that we expect to make us happy, like gifts, sex, food, or friendships, routinely defy quantification. One day, a slice of pizza will make us much happier than good sex, but the next day it will hardly register.

The takeaway from this is that we truly don’t know what will make us happy, so keeping to a strict routine isn’t exactly beneficial. Try some new things! You might be surprised by what you find.

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Alcohol kills brain cells

Alcohol doesn’t actually kill brain cells on a permanent basis. What happens when we’re drunk is that our neurotransmitters are inhibited, but this wears off as soon as we sober up.

The only neural side effect of alcohol abuse is a condition called Wernicke-Korsakoff syndrome, which is also known as Wet Brain. Symptoms of this syndrome include confusion, loss of motor control, loss of memory, and hallucinations, but it generally only develops in people with who are serious alcohol abusers.

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We use one side of our brain more than the other

A recent study found that the idea that a person can be left brain or right brain dominant is only a myth. In fact, humans use all parts of their brain equally, regardless of what skills they excel in.

The idea that attributes like analysis, creativity, or logic originate in one side of the brain is a clear misunderstanding of 1981 Nobel Laureate Roger Sperry’s research on epilepsy. He discovered that certain areas of the brain were involved in different functions like writing, and talking, but never meant for pop psychologists to infer that different attributes went along with these divisions.

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We only have five senses

Our brain governs many more than just five senses. Although the five senses of touch, taste, smell, sight, and hearing are generally given primacy, there are many other senses that the brain processes.

Balance, movement, pain, and temperature are also senses that are processed through the brain. In fact, humans as a species are pretty low down on the sensory ‘food chain.’ We only have a few different ways to process sensory input, unlike animals like bats (who use sonar) or cats (who use their whiskers to judge spatial relationships).

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A lobotomy can cure mental illness

Granted, this is a very old myth, but it was still very popular in its time. During the early 20th century, scientists were desperate for any breakthrough in the field of mental health, and finally landed on the lobotomy as a potential solution for crippling mental illness.

In a lobotomy, the frontal lobe of the brain, which was thought to be the seat of all mental disturbance, was severed from the rest of the brain. In the best case, patients became docile and inert. In the vast majority of cases, patients were completely incapacitated, or killed outright by the procedure.

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Any women’s illness — mental or otherwise — is caused by hysteria

Before the beginning of the 20th century, any time a woman complained of sickness or mental illness, she was diagnosed with ‘hysteria’. This incredibly sexist diagnosis assumed that at least a quarter of women suffered from it, and its symptoms were too numerous to even list.

Now, we know that many mental illnesses and diseases fell under this giant umbrella — everything from anxiety to sexual frustration to epilepsy was diagnosed as hysteria and “treated” accordingly.

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Brains are like computers

Although the metaphor is appealing to many people, comparing the brain to a computer just doesn’t give it enough credit for being the magnificent machine that it is. The brain doesn’t have a set capacity like a computer does, and although there are inputs and outputs in both, we don’t receive information passively like a computer does.

There is a history of comparing the brain to the leading technology at any given time. In the past, the brain was compared to the hydraulic press, as well as the steam engine.

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Bigger brains are better brains

One only needs to look at different animal species to debunk this myth. Some insects or amphibians have tiny brains, but can process a huge amount of information.

The only thing that scientists know about brain capacity is that generally organisms will have a brain that relatively fits their physical size — there are no animals walking around with huge brains on little bodies.

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We are passive observers of the world around us

Our brains don’t just compute the information that they receive passively. As a species, humans are continually looking for patterns, and have the uncanny ability of finding them in the most unexpected places.

Humans are also pretty terrible multi-taskers. Our sensory input is capable of simply blocking out information when our brain gets overloaded — which is why texting and driving is now illegal in many places.

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Men and women have differently shaped brains

It is true that there are minute differences between the male and female brain. However, scientists have spent years trying to correlate these differences in shape to differences in behavior, to no avail.

The fact is, behavior, performance, and personality have nothing to do with the shape of one’s brain.

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We have approximately 100 billion neurons in our brain

For years, scientists confidently assured us that we had approximately 100 billion neurons in our brain, even though no one could actually remember where that figure came from. In hindsight, it’s not really a surprise that it turned out to be wrong.

Just a few years ago, a young neuroscientist from Brazil did some experiments on brains donated for scientific research, and found that humans have closer to 85 million brain cells.

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We can tailor lessons to each child based on the way they learn best

The idea that children can be taught more effectively by focusing on the sensory input that they prefer has recently been debunked. In truth, no one favors one sense more than others, unless they are physically impaired (ie. deaf or blind).

The theory, which attempted to divide children into groups of visual, auditory, and kinesthetic learners, probably came from efforts to supply teachers with more effective, scientific ways of teaching young minds — a nice gesture, but completely devoid of actual fact.

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Learning two languages at a time is impossible

Some years ago, scientists posited that people who were taught two languages at once were slower at learning both because the different areas of their brain were competing for attention. As you may have guessed, it wasn’t true.

Although learning two languages at once does seem impossible, children do it all the time. The truth is although it may be difficult to keep all the rules straight at the beginning, students who are learning two languages at once gain a better understanding of language structure as a whole.

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