There are always theories. They never test EVERY breed, and generalizing about which breed is most intelligent makes as much sense as saying that people with brown hair and blue eyes are smarter than people with blond hair and brown eyes . . . Every dog is an individual. Some breeds seem to have been bred more for cognitive ability than others, but really, with all the emphasis on conformation and arbitrary standards of 'beauty' that type of breeding is too commonly falling by the wayside among too many breeds recognized by multi-breed organizations. It would probably be more accurate to say that the typical working dog is more intelligent than the typical AKC show dog . . . Not an absolute, by any means though.