Canis lupus familiaris share a long evolution with Homosapiens. There are scientific studies documenting the number of human words and gestures dogs understand. I suspect such studies have been conducted with dogs of superior intellect like German Shepherds or Border Collies. If I were to lend Duke and Jake to such a study, I would advise the scientists to look into the number of words and gestures dogs thoroughly understand but choose to ignore. That is the true test of intelligence.
Duke knows the ropes around here pretty darned well. He should. He has tolerated life with me for thirteen years. He knows he truly does not have to do anything I want him to do. Nothing bad will happen if he ignores me. If he is in the pasture happily digging for prairie voles, he will refuse to come when I call. He at least politely acknowledges my request by pausing to look my way. If in his assessment, digging a hole is more important than my shouting, he ignores me. I always wonder what he is thinking when he stops to stare at me intently. Maybe he is checking to see if I am carrying something to eat, which would make the trip worth it. Maybe he is judging the time/distance I would have to travel to get my hand on his collar, at which point he is doomed. He never makes me wait very long, though, and that is one reason why he is the Good Dog Duke.
Jake, Jakey Bakerton, the pup has so much to learn to ignore! He already knows what "sit" means and he tries, but it is impossible for him to be still unless he is around other people, or in a new environment, or is unsure. Then he turns to stone. He learned immediately that I am no one to fear, so he is a wild dog, jumping on the car door as soon as I arrive home, jumping on me, getting in my way, irritating Duke and me with his hyperactive exuberance. He throws himself with reckless abandon into the side of my car, into my legs, into Duke. He has become a hurtling ninja dog, flying through the air to body slam into Duke. He is a giant pain in the arse. He learns quickly, though. He already realizes his name is Damndog.