You know, I've always thought that graph was pretty inaccurate. A village idiot is not overwhelmingly smarter than a chimp. There was a time when the term "idiot" designated people who suffered from profound mental retardation, and anyone that low on the scale is probably significantly dumber than the average chimp. It's not like humans are so much smarter than other animals that our intelligence curves are totally non-overlapping with any other species. Koko the gorilla would probably be somewhere from moderately to severely retarded by human standards, although some of her mental faculties might be significantly better than those of a mentally retarded human. Even highly mentally disabled humans might be graced with neurological anatomy that's only appeared in the last few million years of evolutionary history, but that doesn't mean it's all functioning properly.

A modern car might have tremendous technological advantages over old ones, but drain enough of its lubricant and it'll still run worse than a Model T.