It's a cool idea. I'd bet that it's unlikely for a sufficiently intelligent species (say one capable of creating machines to cross interstellar distances) to st

It's a cool idea. I'd bet that it's unlikely for a sufficiently intelligent species (say one capable of creating machines to cross interstellar distances) to stay dumb, though. Humanity is fast approaching the point where we can edit our genes or otherwise select for intelligence. Even the idea of creating non-human super intelligent agents of some sort is arguably within reach over the course of the next few hundred years. I like to think that though the starting average intelligence for a given species might be lower than others, eventually we all wind up at the same place, either turning ourselves into or building some hypothetically (given the laws of the universe) maximally intelligent system.