2025-05-20

Mammals and reptiles diverged around 300 million years ago. Mammals kept the “lizard brain” –the ancient core that drives instincts like hunger, fear, and aggression– but added a powerful new layer above it: the cortex.

The cortex gave mammals an edge. It could store memories, recognize patterns, and make predictions, skills the lizard brain was not as good at. Primates added more cortex. Humans added even more, until the cortex became vastly larger and smarter than the reptilian machinery it sat atop.

All along, the lizard brain has been in charge. The cortex might tell us “Don’t eat that marshmallow!”, but the final decision comes from deeper down. Sometimes we (our lizard brain) listen. Sometimes we don’t.

In this sense, mammals are “super lizards”, capable of cognitive feats no alligator could dream of.

We didn’t stop there. At least since the invention of writing, we have been extending our “mind” using external tools. A clay tablet can remember that Darius’s father was named Hystaspes– for millennia. Our phones can quickly recall hundreds of phone numbers. Calculators multiply faster and more accurately than most people ever could.

These tools augment our mental powers. And though each is better than us at some narrow task, none yet outperform us across the board.

It is immanent that this will change soon. Our AI assistants will become superior to us at all cognitive tasks.

Note that the cortex doesn’t want anything aside from to model the world and make predictions. AI models are the same, but bigger. In fact, the bulk of their training is on tasks similar to predicting the next word in this ____.

Soon, our tools –our artificial super-cortices– will advise us in ways far beyond what our own cortex can do. And just like with our internal cortex, it’ll be up to us, our lizard brain, whether to take their advice or not.

Our tools won’t replace us. They’ll augment us. We’ll become “super duper lizards”.