Brain Myths


There are many widely held beliefs about the human brain that are factually inaccurate. These myths and misconceptions are common because until quite recently we lacked the technology to study the brain effectively. In other words, the information we now have about the brain is new and has yet to be widely disseminated. Because there is so much misinformation about the brain floating around in our culture, I thought it would be helpful to begin our exploration of the brain by dispelling the most common “brain myths.”

Myth #1: Humans only use 10% of their brains.

Humans use their entire brains. If we didn’t, our brains would be smaller. Your brain is an expensive organ to run–it uses about one fifth of your daily calories1–and natural selection would never evolve such an expensive organ for us to only use 10% of it.

Myth #2: The human mind is a “blank slate” on which culture is written.

This idea, very popular among 20th century sociologists, says that humans are born with little to no instincts, and brains become whatever they’re taught to become. In reality, our brains come with many instincts and predispositions, which are a product of natural selection and individual genetic variation. Our brains are highly adaptive and malleable, but it’s still much easier to teach a child to fear snakes than it is to teach a child to fear puppies, because snakes are much more naturally threatening. Human nature is real and it matters.2

Myth #3: We use our left brains for logic and our right brains for creativity.

Actually, we use both hemispheres for just about everything. Our brain’s left hemisphere typically looks at the world in terms of distinct, sequential details, while our right hemisphere tends to look for patterns and see the big picture – the significance of the details. Logic and creativity each require both of these capabilities.3 When people with  personality types described as “left brained” or “right brained” are given fMRI (real-time brain scans), the scans show activation in both hemispheres, and there’s no correlation between a “right brained” personality and increased activation in the right hemisphere of the brain.4 ­­

Myth #4: You cannot grow new brain cells. 

Modern neuroscience has discovered that we do continuously grow new brain cells throughout our lives, through a process called “neurogenesis.” There are activities we can do, such as exercise, which promote neurogenesis.5

Myth #5: The effects of brain damage are always permanent.

Modern neuroscience has also discovered that with the right training, people with massive brain damage can overcome their disabilities. Take stroke victims, for instance. Often a stroke kills the part of the brain that controlled some function, such as the use of one’s left arm. The arm is just fine, but the brain doesn’t know how to control it, because the cells that used to control it are dead. Even though we’re capable of re-growing some brain cells, we’re not likely to re-grow an entire section of the brain. But other, still living sections of the brain can be repurposed to control that arm. The stroke victim must then be forced to learn to use that arm, from scratch, as though they were a baby. With time and effort, they can regain control over that arm, effectively recovering from the damage done by their stroke.6

Myth #6: The brain and the body are separate and distinct from one another.

It’s widely believed that the brain isn’t much influenced by what the body is doing, or that the brain can easily ignore what’s happening in the body. It’s also widely believed that mental problems cannot translate into physical symptoms. This mind-body separation has been popularized by sources ranging from Rene Descartes to The Matrix, and yet there’s no evidence to back it up.

In fact, there’s a lot of evidence that shows how the mind and the body continuously influence each other. If you exercise your body, your brain becomes more alert, more focused, and more intelligent.7 If you eat terrible food, your brain’s abilities decline.1 If you adopt confident body language, you’ll start to feel more confident and think more confident thoughts.8 If you convince yourself that you’re in grave danger, your body will start to show signs of panic. Psychologists call this phenomenon self-perception. The body and the mind look to each other for information about how to feel, think, and act.9

Works Cited

1 MacDonald, Matthew. Your Brain: The Missing Manual. O’Reilly Media, 2008.

2 Pinker, Steven. The Blank Slate: The Modern Denial of Human Nature. Penguin Books, 2003.

3 Kauffman, Scott Barry, PhD. “The Real Neuroscience of Creativity.” The Huffington Post. September 5, 2013.

4 Neuroscience News. “Researchers Debunk Myth of “Right-Brained” and “Left-Brained” Personality Traits.Neuroscience News. August 14, 2013.

5 Perlmutter, David, MD. “Neurogenesis: How to Change Your Brain.” The Huffington Post. November 2, 2010.

6 Doidge, Norman. The Brain That Changes Itself. Penguin Books, 2006.

7 Medina, John. Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School. Pear Press, 2008.

8 Cuddy, Amy. “How Your Body Language Shapes Who You Are.” TED Global 2012.

9 Ben-Shahar, Tal. Psychology 1504: Positive Psychology. Harvard Open Course, 2009.

Image Credit

Crafty Dogma. “Phrenology.” Creative Commons 4.0.

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