I'm referring to intelligence and reasoning. Humans have not biologically evolved in any significant way in tens or hundreds of thousands of years. We've advanced through passing down and building on previous knowledge, which requires education. If you're uneducated, you are very literally no smarter than a medieval peasant. We didn't get biologically smarter, we iterated on knowledge that the people who came before us learned, and then we pass down what we learn. If you spent science class dipping your fingers in glue and peeling it off instead of learning cellular biology, you are not particularly functionally different than a medieval serf, simply acting on emotion and lashing out at everything you don't understand. And for the people in this situation, there's a lot they don't understand.