Intellectuals are humble creatures that trade external spoils for rich internal lives. Deep and introspective, they're often in their own heads pondering life's big questions like "Why's my human always pointing the phone at me?"
Perhaps as a result of their active minds, Intellectuals are also pretty lazy. They prefer basking in the sun or staring off into space. After all, being intellectually rigorous is exhausting. This cosmic inquiry tends to easily thrust them into a kind of "hermit mode" marked by long bouts of extreme physical inactivity.
Moose from Frasier is pretty smart. He won the role for the sitcom after only 6 months of training. His smarts also won him on a cover of Entertainment Weekly.
Note: I don't think that "pure bred" should be on the list, since it has nothing to do with the dog's success or demeanor.