You can't get any dumber and still dig ditches and collect taxes. Five thousand long lifetimes of chip chip chip without a glimmer of innovation. Five millenia of mommas. If kids remembered half what their grandparents told them, there might still be people singing Sumarian folksongs in the original. Blink and you'll miss the difference.
Humans are even more closely related to bonobos.
And humans are so closely related to those morons who chipped exactly the same rock tools for five thousand long lifetimes, that it isn't even funny. A shave, a haircut, and one thin clue. It is not your imagination that civilization is run by idiots, and it is not an accident. Civilization was started by the very dumbest animals capable of pulling it off, and they're still running it today. Excuse me, I'm supposed to go help with a rock garden.