SMALL DOG SYNDROME

Dog breeds classified as toy or small have higher owner-rated scores on aggression and fear, as well as lower trainability scores. Large and giant dog breeds, in contrast, are on average the most trainable and the least aggressive and anxious. "I suspect it has to do with the way small dogs are treated as compared with large dogs," Ruple suggests. Good behavior in a big dog is often judged as more of a necessity, whereas people may let little dogs off the hook.