Brain Anatomy: Three Evolutionary Leaps Forward
To understand what our brains are up to, we need to know a tiny bit of anatomy. Since you, the reader, and I, the blog writer, are human we are equipped to get the gist of a complex system by comparing it to simpler, more familiar things.
The human brain can be divided into three layers:
- The oldest, deepest layer, sometimes referred to as the “reptilian” brain, is responsible for homeostasis
- The middle layer, more recently evolved, referred to as the “mammalian” brain, is responsible for emotion
- The outer layer, a very recent phenomenon in evolutionary history, is responsible for intelligence.
Three layers, three functions, three evolutionary leaps forward.
The Badass Lizard of Homeostasis
I picture a badass lizard with a long tail at the base of every human brain. Lizzy doesn’t think. She has no emotions. She is a cluster of nerves acting and reacting in response to cues from my environment.
Depending on the information streaming in from my five senses, she decides whether I am safe enough to sprawl over a warm rock and doze, or if I’m frozen, heart pounding, muscles taught, waiting to fight or to flee back to the safety of my dark cave.
Badass Lizard works a whole control panel of dials, up or down.
If it’s hot – I sweat.
It it’s cold – I shiver.
If there’s danger – I escape.
And when the coast is clear, she boots me out the door in pursuit of huge gobs of anything luscious.
Lizzy doesn’t give a rat’s patootie about you, she only cares about me. Specifically, her job is to keep me alive and well oriented in my world. She works to keep me warm, safe, fed and…well, there’s one other function she concerns herself with (but it is suitable only for the imaginations of readers over the age of consent).
The Wolf Mom of Emotion
In the warm, middle layer of every human brain, lives a wolf mom. She’s furry and cuddly, but don’t let her fool you, she’s a badass, too. Unlike Badass Lizard, she can be a badass on behalf of you, my mate, my pups or my pack. She is hormones in the blood, emotional energy and non-verbal communication. See her smile when friends come to visit? See her heart break when she has been alone too long? She compels me to do the right thing, to try to fit in, to want to be good.
The Blog Writer of Human Intellect
But Wolf Mom doesn’t paint pictures, sum the total number of calories in a value meal or design in html.
That’s the job of the recently evolved layer of human intelligence. She is the writer of blogs, the payer of bills, the explorer of the local library.
If Blog Writer could be in charge of my brain, things would be different! I would get up early, dress for success and stand tall in the face of injustice. I would perform every task on my list and be asleep in my bed at a respectable hour. I would only eat one cookie and drink one glass of wine. What others think of me wouldn’t matter. The only words out of my mouth would be the words I meant to say. I would make reasonable choices every time and do it all with an attitude that Rogers and Hammerstein would envy…