The Reptile Mind

As humans evolved (from reptiles, to lower mammals, to modern man) so did our brains, both in size and complexity. An interesting aspect of this evolution is that, instead of simply expanding, our brains added on new components to augment the old ones. If you look at a cross-section of human brain, you can see evidence of it’s evolutionary history. The original reptilian brain resides in the center. The lower mammalian brain formed around it. And the frontal lobe of the human brain, lastly, surrounding it. The neurologist Paul McLean called this “the triune brain”… I call it “my turducken.”

“MacLean says that the three brains operate like three interconnected biological computers, each with its own special intelligence, its own subjectivity, its own sense of time and space and its own memory. He refers to these three brains as the Neo-Cortex or neo-mammalian brain of the frontal lobes of the cerebrum; the Limbic or paleo-mammalian system of the mid-brain and thalamus; and the Reptilian brain – the brain-stem and cerebellum.  Each of the three brains is connected by nerves to the other two, but each seems to operate to some extent independently, as its own brain system with distinct capacities. Each successive layer of the Triune Brain contains a progressively more complex infrastructure of nerve cells, and the neurons which connect them are terminated within the three levels, almost as if the higher functions were tacked on as an afterthought.”

The reptile brain handles our basic survival instincts while our lower mammal brain handles our emotions. Lastly, the frontal lobe is in charge of abstract thinking, empathy, and all the other things that make us (and other higher mammals) so unique in this world. What fascinates me is how these ancient artifacts lodged in our minds are still slaves to the old rituals. You would think that it’d be somewhat like the human appendix… obsolete with no signs of functionality. But we can see the lower brains at work around us every day.

Think of things in terms of the reptile mind next time you are out at a bar on a busy night. You can see ancient courtship rituals at work… males establishing their alpha-ness… People ganging up on the weak… nodding their heads in approval of the strong… and it becomes more pronounced as the alcohol takes it toll. The medulla oblongata activates… fights break out… muscles are flexed… colors are brandished.

When you understand that we are slaves to these atavistic tendencies, it explains so much. Like why so many of us to behave in petty ways under the pressure of social scenarios. We hold ourselves up to this lofty standard of human behavior and yet, at times, we seem to automatically react to situations and revert to behavior unfitting of a species so supposedly advanced and cultured.

I have felt guilty in the past when I’ve reverted to old reptilian behavior. There have been instances where I wonder why I have a hard time warming up to certain people… times where I’ve been irresistibly drawn to “show off” in front of others… times where I’ve been unnaturally butt-hurt over things that shouldn’t matter… and I have had also been upset with friends who acted in strange ways when girls are around and I’ve judged them for it… thinking of it as a character flaw or an issue of maturity. When I think of it from this new perspective though, this “auto-pilot” behavior becomes forgivable, natural and humorous.

These ancient subroutines govern our happiness and, when they kick in, we are at their mercy. I vow that we all stop beating ourselves (and others) up over these little slips in civilized behavior. Let’s embrace our reptilian components and learn to  appreciate these little rituals and outbursts when they happen. This is not to say we should just run amok with little regard for other people’s feelings… remember, the reptile part of brain occupies less than 5% of the total mass of our gourds. Rather, we should recognize it for what it is so that we can understand and adjust our behavior for the better whenever possible.

Update:  Seth Godin on Quieting the Lizard Brain

1 Comment

• 
  jeremiah jones February 4, 2011 at 10:07 pm

  true reptilian mind is an interesting article. I wonder why this is….are we the hybrids of reptilian humanoid aliens?