The unnecessary size of the human brain.

This dawned on me a few weeks ago, and I don’t think I’ve really solidified it into a solid idea yet, so this might not quite make sense.

A few years ago I was watching a turkey in my backyard and I had suddenly figured out after decades, why some birds bob their heads forwards and backwards when they walk.

Ever since I was a kid in brooklyn and I saw pigeons always bobbing their heads when they walked, I always assumed that there was some bone linkage in their bodies that in order to move their legs, the structure of their skeleton required that they move their head forward and back with each step. Hey, I was five.

But I was watching this turkey against the backdrop of the woods behind it, and because of that perspective I was able to make this amazing insight: It had nothing to do with bone linkage, it had to do with keeping its head still.

I found this to be a profound insight, mostly because it jarred my 5-year-old’s version of a deeply held understanding, only because I hadn’t really thought about it since I was 5.

So then I thought: well, why does the turkey need to keep its head still?

The first thing that came to mind was that its brain was too small to process all the moving data, and it had to sit still so it could get a grasp in its little head of what was going on around it. I figured the poor turkey only saw the world in snapshots, and didn’t absorb what was going on while its head was moving forward.

So apparently I hadn’t progressed much beyond my 5 year old mentality.

When I was 5, there was no internet, but now there is, so I looked it up.

And I was wrong, but I was close.

It is true that the bird keeps its head still so it can get a non-moving view of the world, but not because its brain is too small, but because it is much easier to spot movement of predators when you’re not moving.

I always wonder how scientists know things like that. Seems like a reasonable answer, but somehow we trust them to be right.

But maybe I wasn’t completely wrong, the reason birds can’t see predators moving against the background while they are moving, is because their brains are too small and can’t process all that information. A computer could do it.

But that got me thinking, it’s pretty amazing what a bird with a brain the size of a pea can pull off.

Which makes you wonder, given the size of the human brain, you’d think we’d be able to do way more stuff than a bird, and we can, but not proportional to the the amount of extra hugeness the human brain is compared to a bird’s brain.

So what does all that extra brain do?

Well, it has feelings, it has memories, it has instincts. It has biases, oxford commas, and prejudices. It has schizophrenia, defense mechanisms, a sense of music and rhythm. It has the ability to perceive moving things while it itself, is moving. It has right-brain control of muscles that allow you to breath, chew gum, tap your head and rub your stomach, all at the same time.

And it has self awareness and intelligence. This is the part where my idea hasn’t completely been flushed out yet.

But the basic idea is that evolution made a lot more brain than needed to be self aware, and have the intelligence it has, and along the way it picked up a lot of baggage that it doesn’t need, but worked well enough to get by until the intelligence part showed up.

There is a lot of unnecessary human brain, doing all sorts of unnecessary things.

And these things may have been necessary to get to where we are, but they don’t always help now.


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