I think that alot has to do with the trainer also. When a breed becomes popular with the general public, every joe blow gets one. and sadley to say many will not train them. so then you have a bunch HARD TO TRAIN BREEDS, I think all breeds are intellent. It is all in how they are taught. If I took alook at the different breeds that I have owned. I would say that my rottie Caleb was the most intellent. And you all know that I own the #2 dog Poodle but based on mine the rottie was more intellent and easier to train. He was more layed back than Riley.