The Reptilian Brain: A Prehistoric Hold-Over, Hiding out in the Human Head

This is the story of a man.  A simple man, really; average in every way; typical in looks, intelligence, and charm.

I invite you to travel along with us; to discover how the oldest and most universal part of his brain affects his day, his views, his dealings with those around him, and his status in the world.

Join me, won’t you?

Meet Jack and his reptilian brain.

Jack, a Human of the Reptilian Persuasion

More than a handful of evolutionists will attest to the “fact” that humans are descendents of reptiles (the quirkiest of those even believe that a few lizard/human hybrids still walk among us).  

No matter your personal opinions about the theory of evolution, there’s no doubting that a portion of your brain is similar, if not nearly identical, to the structure and function of a reptile’s brain.  

According to Paul D. MacLean (the physician and neurosurgeon – not the rugby player, the ice hockey player, or the Aussie politician), the human brain is constructed of three major areas:

  • The upper and outer part of the human brain can be referred to as the neocortex.  It’s responsible for cognitive thought and movement. 
  • Blanketed by the neocortex is the limbic section of the brain.  You can thank this portion for emotions like guilt, affection, and hatred.
  • And at the center of it all, housed within the base of your skull, is what MacLean labeled the “reptilian complex” or the “R-complex.”  It is the reptilian brain, it is our oldest and most instinctive machine, and it’s responsible for most of Jack’s story.

A Reptilian Brain Treat

Before Jack takes us along for a ride, he would like to stop for a snack – his favorite snack, in fact:  Peanut M&Ms.  Never had them?  Well, you simply must try one in the name of science.  You see, this candy treat is a good (and delicious) model for the human brain.

The hard outer candy shell of the M&M is much like your brain’s neocortex.  Its manufacture is complicated, just as human evolution’s manufacture of the neocortex took millions of years.  Its color varies, just as the neocortex’s cognitive and motor skill levels vary among humans, depending on education and heredity.  It’s tough; it won’t melt in your hand (which can be compared to the tough decisions and hard thinking that occur in your neocortex).  And, don’t forget its placement in the manufacturing of the candy – it comes last, blanketing the rest of the treat, just as evolution most recently blanketed the human brain with the neocortex.

Next, is the chocolate.  Comparable to the limbic system, the chocolate is emotional (go ahead, tell me you’ve never indulged in a chocolate bar, or two, when you were down).  It requires some processing, but its ingredients are older and more primitive than those of the outer shell, reminding us of our own, antique limbic brain systems.  Its color and flavor is consistent from piece to piece, just as our limbic systems vary little from person to person (we all experience similar emotions, but deal with them differently).  In the manufacturing process, it is applied before the outer shell (neocortex), just as the limbic system evolved before the cognitive portion of the human brain.

     And finally, the peanut.  This is the reptilian brain:  the most simple, organic, and naturally unscrewed-with-by-evolution portion.  Like the peanut, your reptilian brain is embedded in the center of your noggin, it is largely consistent from person to person, and it has remained unchanged for millions of years.  It does not make us uniquely human, for other creatures share this “peanut,” but it does give us the basis from which humanity sprung – just as the peanut gives the chocolate and the candy shell a medium, a center, on which to build.

Jack’s Morning View

Jack stumbles from bed, makes his coffee, forages for the remote and flips on the TV.  He does this every morning.  Jack feels unable to shower, eat, or feed the dog until he’s had a dose of java with a side of Whoopie.

Today on The View, President O’Bama is visiting with the girls.  He refers to our reptilian brains as causing humans to be cautious when they encounter people that look or sound different from themselves.  He cites this part of the brain as being accountable for racism, and that it must be fought against.

Jack ponders the President’s point, largely agrees, knows that he will forget about it by noon, and breathes deeply as the camera pans to Elisabeth, who makes Jack smile (she reminds him of his sister, who lives 3 states away).

Then a commercial comes on.  A half-clothed man with plentiful muscles, a resonant voice, and skin as smooth as a caramel latte travels the world while openly declaring that he smells better than most men.  Suddenly, Jack, the man who never uses anything stronger than unscented antiperspirant, decides he’s had enough coffee and goes directly to his daily planner and adds “Old Spice” to his to-do list (directly under a get-rich-quick web address and the name of an exercise program designed by a trainer-to-the-stars).

Now, Jack can give the dog her kibble.

Gecko Jack’s Analysis

Jack’s reptilian brain played a large role in his morning happenings.  The first important thing to point out would be the R-complex’s driving of Jack’s routine.  This part of the brain is largely ritualistic, driving us to perform “safe” tasks that have proven effective in the past.  Sure, his morning could be more productive or more efficiently run, but with his reptilian brain in charge, Jack feels drawn to his routine.

The second thing that speaks reptilian is the importance that Jack places on familiarity.  He could turn on any of his 264 channels, but he chooses the familiar faces of The View.  He is drawn to Elisabeth because her face reminds him of a loved one and her political views align with his.  Jack largely discards the words of the President because the most primitive part of his brain tells him that the President is of a different class, a different race, and a different party (which, ironically, is just what the President said it would do).

And finally, there’s the media’s grip on Jack’s lifestyle.  The reptilian brain is greedy, envious, aggressive, and compulsive.  Advertisers have consciously used our own reptilian brains against us for generations, triggering our desires to keep up and get ahead.  They’ll subliminally use sex, money, self image, power, success, or food to kick our reptilian brains into action (which, strangely enough, seems to hold a direct connection to our wallets).


Jack’s Primeval Commute

Jack watches the seconds scroll on his watch while he hugs the bumper of the Mercedes in front of him.  He has ten minutes to get to work, and five miles to go.  His knuckles steadily drain of color while a familiar pressure builds in his temples.

Suddenly, traffic speeds up and the Mercedes moves ahead.  A Volkswagen slips in between him and the Benz like a Lego peg.  

Jack’s on the horn.  He’s screaming profanities.  His arm is out the window, a single digit pointing toward the sun.  Now his head’s out the window.  In his blind rage, he barely notices the VW driver’s slow retreat into the hollow of her bucket seat, or the splattering of wet toast crumbs he’s left on his side view mirror.  

Iguana Jack’s Analysis

The reptilian brain is territorial.  When the VW “stole” Jack’s spot, his reptilian brain kicked into action, overrode all rational thought, and road rage took over.  In a reaction like Jack’s, the reptilian brain becomes so dominant that logical thought is nowhere to be found.  

By the time Jack poured his first cup of coffee at the office, his cognitive mind regained control over his reptilian brain’s hair trigger.  His mind repainted the picture of the wide-eyed woman at the wheel of the beetle, of the stares from the drivers around him, and of how ridiculous he must have looked…red-faced, eyes bulging, extremities flying.

With practice, humans can teach their cognitive minds to jump in, hold the rage, and wait until the reptilian brain retreats to make a rational decision.  


Jack Snakes through His 9-to-5

Jack bears his daily workload with valor:  he files, he fields calls, he jams the copier and slithers away, undetected by all but the mail clerk.  While he goes about his daily work routine, his heart beats, his lungs breathe, his blood circulates, his food digests, he maintains balance, he regulates his temperature, and he jumps at loud noises.

Back at his desk, he rearranges his pencils according to size.  He flips the photo of his mother so she can’t see him eating his second Ding Dong, then he plucks a paper clip from the carpet and adds it to his extensive collection.

Box Turtle Jack’s Analysis

The reptilian brain is deceptive.  Without conscience, it does what’s necessary for survival, without thought of morality.  It’s superstitious, obsessively compulsive, conformist, and it drives us to hoard items.  All of these traits are important for the existence of wild animals, but if left unchecked, hold the potential to overrun Jack’s daily workings, as they have.  Jack has allowed his reptilian brain to dominate his conscious mind, boxing him in like…well, a turtle.

The reptilian brain is also responsible for Jack’s unconscious bodily functions; it never sleeps.  It runs Jack’s machine so he can busy himself with running, or breaking, the copy machine.


Jack’s Boot, Scoot, ‘n’ Boogie

After a long day at work, Jack splashes on the Old Spice that he picked up on the way home and dons his lucky polo, his favorite jeans (worn through at the knees), and his one-of-a-kind diamondback rattlesnake boots.

He hops in the car and heads for his favorite watering hole.  There, he spots a beauty at the pinball machine.  He puffs out his chest, pushes back his shoulders, sucks in his muffin top, hooks his thumbs into his belt loops, and pushes out his chin.  When his seductive strut is finished, he holds up the wall with a flexed arm, spreads his feet wide on the ash-stained floor, and gives the Pinball Princess’ topographical map a roundtrip voyage with his eyes.

The woman’s fingers stop their hammering.  Though her nose smells a cologne that reminds her of leather tanned with pumpkin pie spice and her eyes see a man who’s ill-dressed in dead animal parts, her vegetarian, animal-activist self can’t help but submit to this man who is covertly, and indescribably sexy.  Without a word, he places a hand on the small of her back and escorts her to a table in a dark corner of the bar.    

Ok, a bit far-fetched but it can happen - Her reptilian brain has taken over…her cognitive brain takes a back seat, along with her convictions…

Crocodile Jack’s Analysis

Jack’s aftershave and boots are remnants of his reptilian brain’s desire to boost his self image.  His pulling on of comfortable jeans and his “lucky” shirt play into his primitive tendencies toward superstition and ritual.  His favorite watering hole might only be his favorite because it feels familiar, safe, and doesn’t require a great deal of cognitive thought to get there.

The reptilian brain is also responsible for courting and reproduction.  Jack’s reptilian mind guided his body in approaching the object of his desire, and that approach was successful.

Though words stimulate the conscious mind, the reptilian mind relies on images.    Jack could have apologized for his boots or offered to have a pair made for the princess.  Either way, it wouldn’t have mattered.  The Pinball Princess’ primitive mind processed Jack’s seduction dance and discounted all other factors that her conscious mind would have probably dismissed. 


Doubled-Edged Intelligence

The reptilian brain is indispensable.  For unconscious breathing, autonomous fight and flight, and reproductive tendencies, it can’t be beat.  But there are instances in which our distinctly human brains’ outer layers should trump its inclinations.

There are many who argue, very effectively, that the reptilian brain is the root cause of racism, xenophobia, Semitism, and all other cultural and religious prejudice.  This makes perfect sense when you consider that the reptilian brain has contributed to survival with an “Us vs. Them” process.  You see, in the past centuries, those animals and humans who were unfamiliar posed serious threats to territory, health, and life.  This is rarely the case today.  And if it is, our cognitive minds have already learned of those dangers, and can base prejudice against known individuals on fact, not speculation.

In many instances, the knee jerk reactions of the reptilian brain can be imprudent.  But in other instances, the reptilian brain still contributes to our prosperity.  This is where Jack’s, and your, neocortexes come in handy.  Abraham Lincoln did it well.  If he found himself angered by a person or a happening, he wrote his feelings down on paper, in letter form.  But he would then place it into his desk drawer.  After his cognitive brain had a chance to talk some sense into his impulsive, reptilian brain, he would then deem the letter either no more valuable than kindling for his fire, or worthy of a stamp.  Controlling the reptilian brain is a fine craft, but one that a complex mind, like the human one, is sure to conquer with practice.

Jack is not a reptile, nor is he any hybrid of such.  But he does possess a hold-over from 200 million years ago, when reptiles sported brains similar to the one that lies at the base of Jack’s skull.  

In time, I have faith that Jack will learn to value his reptilian brain for what it really is:  a driving force and a life source.  And that he will learn that his R-Complex is best left to the behind-the-scenes functions.  Because, you see, an open mind, a self-aware mind, is one that uses its peanut only for sustenance, and its chocolate and candy coating for enriching the flavor of life.


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