The Science Behind Your Lizard Brain and Why You Can’t Control It

Because despite what the textbooks say, you are not a lizard.

Daina Hazel
Oct 16 · 6 min read
Image for post
Image for post
Ralph Steadman’s The Lizard Lounge 1971 https://www.humancondition.com/method-in-the-madness/

Let me start by saying addressing the elephant in the room. Yes, that picture is a room full of evil, distorted-looking reptiles conjured up by the drug connoisseur and well-renowned author, Hunter S. Thompson, whilst on an acid trip.

Although this article has nothing to do with Hunter, this pic from his novel popped into my head after hearing yet another person refer to our lizard brain, as if we’re all actually reptiles just pretending to be humans. Maybe you’ve heard the term?

People speak of the “reptilian brain” as if we’ve got some small ancient fossil inside of our brains. It’s used in marketing to appeal to your inhibitions and animalistic desires, but that’s not actually what’s happening when you give into your impulses.

We’re not easily influenced because we’re all living with an unhinged lizard brain, or monkey brain for that fact. It’s just not that simple, and when it comes to our minds, we shouldn’t make things more complicated by repeating unnecessary and false theories, like this one. …sigh. Let’s go back to the facts, shall we?

The Theory of Your Three Brains

The reptilian brain, as proposed by Paul MacLean in the 1960s in The Triune Brain in Evolution, was thought to have been one of the three separate brains us humans have: Reptilian, Mammalian (Limbic), Primate (Neo Cortex).

Image for post
Image for post

“Man, it appears, has inherited essentially three brains. Frugal Nature in developing her paragon threw nothing away. The oldest of his brains is basically reptilian…”

The theory goes a bit like this: MacLean believed our brain could be divided into three parts and that each part was a “brain” that represents a specific evolutionary level starting with the ancient “reptilian” brain. It was claimed that this area is responsible for our instincts and survival mode, i.e. to keep us safe by triggering things like reflexive behaviors, reproduction, and regulation of our physical body.

Then there’s the mammalian brain, being the next “brain” that developed in line with that of other mammals. This part is linked to our emotional well-being, safety, and learning and together with the reptilian brain they operate subconsciously (i.e. we aren’t consciously directing them to do anything).

Having transitioned from being a lawyer into a therapist, and based on how much this theory is cited in and out of academia, I’d assumed it was true. But as a hypnotherapist, my curiosity into the subconscious mind led me to finally establishing whether we did in fact have three simple “layers” and if it really was that simple. It turns out many more important and well-educated neuroscientists have asked the same question and the answer they came up with is: no, it’s not that simple.

You Don’t Actually Have A Lizard Brain

To be clear, you don’t have a lizard brain or a brain from any reptile for that matter. This was just a theory and unfortunately, it hasn’t lasted the test of time. Put simply, MacLean believed that brain evolution was an additive process i.e. new layers of brain tissue would grow and develop on top of old layers, leading to the existence of an “old brain” with a “new brain.” But the issue that neuroscientists have known for a significant time now is that our brains didn’t develop like this.

“Adding on is almost certainly not the way the brain has evolved. Instead, the same structures have become modified in different ways in different lineages.”

Terrence Deacon, PhD., University of California, Berkeley

Scientists have made it clear that animals like rodents with “less complex” brains have not simply evolved into another species with slightly more complex brains until the appearance of humans (with the most complex brains of all). But it’s almost become commonplace for people to reference our “lizard brain” or the “reptile brain” as the part of you that you need to control or fix in some way. It’s been used in marketing and psychology and if you see it again, just know that it’s simply unfounded.

“A lot of our contemporary advances ride on top of his work, even though in hindsight it was misleading.

— Terrence Deacon, PhD., University of California, Berkeley

Where did MacLean get all of this from? Well, after an experiment in the ’70s, he observed that after removing the “reptilian” part of a monkey’s brain, the monkey’s behaviour changed so much that it no longer aggressively gestured in the mirror, which was apparently typical of “reptilian behavior.” Not only that, his claims about that specific part of the brain belonging solely to reptiles have proven false.

Unfortunately, this theory has stuck around for the sole reason that it’s simple. It’s easy. People like being able to pinpoint their behaviours, particularly when it is supported by people we trust. In particular, it garnered a new wave of support after being featured in Carl Sagan’s Pulitzer Prize winner, The Dragons of Eden, despite him stressing that it wasn’t necessarily proven and it was oversimplistic. So perhaps it’s time to let go of the lizard brain and focus on what’s actually true. Don’t you think?

What You Need To Know

What you can take away from this is that you don’t have three distinct layers that developed from a reptile. But you do have a subconscious mind that controls a lot of what you do. We are very similar to mammals and, as I wrote a few months back, our subconscious mind can often feel like a caged Chimpanzee with intense desires and irrational decision-making tendencies, but that doesn’t mean we can’t control it.

Mammals tend to have strong emotional bonds between family members, and they generally care for their young after birth…Mammals tend to have good memories, especially for events that created strong emotions.

Brain: The Inside Story, American Museum of Natural History

So, yes, we are similar, but at the end of the day, we’re not monkeys, we’re humans and we’re complex. What you should pay attention to is that you have a conscious mind and a subconscious mind. Mixed up in all of that subconscious activity is a whole host of programs that you’ve learned since you were born about how to live, what is safe, what isn’t, what you like, and what hurts and so forth. These programs are extremely important and they are the key to changing any type of behaviour or belief that isn’t serving you.

Studies reveal a subconscious brain that is far more active, purposeful and independent than previously known.” — Benedict Carey, The New York Times

So while people may claim to capitalise on your reptilian or mammalian tendencies through persuasion, influence and subliminal messaging, you actually hold the power. You’re a human, remember. You can train your mind so that you do, think, feel and believe whatever you want, you just have to direct it and stop giving over power to the idea that it’s the animal within and that’s how it’ll always be. This is a slippery slope down to a hopeless, anxious, or depressive state. I’ll leave you with these three facts:

  • You’re more powerful than you believe;
  • You can hack your subconscious; and
  • You are in control of your brain and your mind.

And when it comes to Hunter S. Thompson’s hallucination about our inner reptile, well, he was probably just really, really high.

Check out my articles here and here to find out how to change your subconscious mind — trust me, it works.

Mind Cafe

Relaxed, inspiring essays about happiness.

Daina Hazel

Written by

I won’t fix all of your problems, but I’ll change your thinking so that you can. Psychotherapist, Hypnotherapist, Lawyer. Reach out@ info@dainahazel.com

Mind Cafe

Mind Cafe

Relaxed, inspiring essays about happiness.

Daina Hazel

Written by

I won’t fix all of your problems, but I’ll change your thinking so that you can. Psychotherapist, Hypnotherapist, Lawyer. Reach out@ info@dainahazel.com

Mind Cafe

Mind Cafe

Relaxed, inspiring essays about happiness.

Medium is an open platform where 170 million readers come to find insightful and dynamic thinking. Here, expert and undiscovered voices alike dive into the heart of any topic and bring new ideas to the surface. Learn more

Follow the writers, publications, and topics that matter to you, and you’ll see them on your homepage and in your inbox. Explore

If you have a story to tell, knowledge to share, or a perspective to offer — welcome home. It’s easy and free to post your thinking on any topic. Write on Medium

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store