A Top Myth About the Way Our Brain Works
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Have you heard that we have a reptilian, mammalian, and rational brain?
If you have, I'm not surprised! This is an extremely common belief in the yoga world. But it's no longer considered accurate by modern neuroscientists.
It's an old myth we should let go of! 😱
This myth is also known as "the triune brain". The basic gist of this myth is that our brain evolved in three layers:
Reptilian brain: The oldest and deepest layer is the "reptilian brain" (also called the "lizard brain" or your "inner beast"). This layer is said to house our base instincts.
Limbic system (emotional center): The middle layer of the brain is claimed to be our "emotional center" – a.k.a. the "limbic system". (Our emotions are said to stem from our ancient mammal ancestors, so this layer of the brain is also called the "mammalian brain".)
Neocortex (rational center): Finally, the outermost layer of the brain is said to be the newest layer. It's called the neocortex and is allegedly the "rational center" of the brain.
Although this triune brain model tells a neat-and-tidy story that's easily digestible, it's an oversimplified model that's been scientifically disproven. Evolution doesn't actually work this way, and our brain certainly doesn't function this way.
Rather than consisting of localized "centers" of psychological function (the emotion center, the rational center, the pain center, etc.), psychological functions actually take place on a whole brain level.
Our brain consists of a vast array of neural networks that span multiple brain regions to coordinate everything about the way we think, feel, perceive, and emote.
In other words, brain function is unimaginably more complex than the outdated triune brain model gives it credit for.
The Triune Brain Myth in Yoga
This scientifically disproven triune brain model unfortunately underlies many outdated approaches to psychology, and many of these ideas have made their way into the yoga world in the form of:
content in yoga teacher trainings
explanatory models in many somatics-based practices
approaches to psychology in numerous yoga therapy programs
"Your Brain Is Not an Onion With a Tiny Reptile Inside"
This brain myth is a really tough one to shake – probably because it resonates with many common beliefs in our society about human nature.
For example, one story we're often told about our "triune brain" is that our rational brain must work to keep our emotional brain "in check", or under control.
This is completely untrue, but it overlaps nicely with our (inaccurate and gender essentialist) societal stereotypes that men are inherently rational and women are inherently emotional – and that rational men should therefore be "in charge" and in control of emotional women.
As you can see, holding inaccurate beliefs like this about the brain is not only simply wrong – it may also play a role in reinforcing gender inequalities in our society!
Thankfully, "your brain is not an onion with a tiny reptile inside" 😛 – which is the title of a paper written by scientists aiming to dispel this old myth (referenced below)!
Update Your Knowledge of the Brain to Enhance Your Yoga Teaching!
Learn the essential insights yoga teachers should know about how our brain works – and how this knowledge impacts our yoga practice and teaching – in my continuing education course Welcome to Your Brain: New Nervous System Essentials for Yogis!
This 4-hour course counts as CE hours with Yoga Alliance, and you can take it for free with the 7-day trial on my site! 🤓 🧠
References:
Barrett, Lisa Feldman. "That Is Not How Your Brain Works." Nautilus (2021).
Cesario, Joseph, David J. Johnson, and Heather L. Eisthen. "Your brain is not an onion with a tiny reptile inside." Current Directions in Psychological Science 29.3 (2020): 255-260.
Howard‐Jones, Paul A. "Evolutionary perspectives on mind, brain, and education." Mind, Brain, and Education 8.1 (2014): 21-33.