Did Our Brains Evolve From Reptiles?

Your brain is more ancient than you think—and part of it still acts like a reptile's. 🦎

Daniel Levitin breaks down the evolutionary layers of the human brain. The most primitive part—the reptilian brain—is responsible for basic survival: finding food, escaping danger, and reacting fast. It’s a small, motor-based system that we share with snakes, lizards, and other lower animals. The cortex, which literally means “bark” in Greek, is the outermost layer of your brain and evolved later. That’s where higher-level functions like speech, decision-making, and planning for the future come in. But deep inside? That ancient startle response you feel when you hear a loud noise? Pure lizard. This layered evolution explains why we sometimes react before we think—because your lizard brain still runs the show in key moments.