1) The official ranking of "most intelligent dogs" doesn't actually measure intelligence!
On the American Kennel Club's website, they have a list of "most intelligent" dogs. I quickly sifted through the list to find my dog's breed - Shih Tzu. I found them smack dab at the bottom of the list. Huh. At first i thought, why are Shih Tzus so dumb? But then I got to thinking, what makes a dog "intelligent"? This ranking is actually based more on obedience and aptitude towards following commands. So when I tell my dog to sit or fetch and he denies this seemingly simple request, he might not be dumb...just uninterested in the task at hand, thus, he makes the decision to decline my orders with a sassy glance my way. Which leads us to the next reason...
2) Your dog gets how the reward system works. A little too well.
"Sit, Columbus!" He stares. "Fetch, Columbus!" He barks. I pull out a treat in plain view and Columbus starts getting antsy. "Sit, Columbus!" He sits. "Fetch, Columbus!" He fetches. "Stay!" He stays. I feed him the treat and then try and make him follow commands again - but he notices I don't have any more treats, so he ignores me. When I call Columbus to come and say I have "a snack" he'll come running, but when he sees I don't have anything he'll immediately turn around and go back to bed. Columbus' logic is: If I do what you say and don't get a treat, it isn't worth my precious time and effort.
3) Less time moving means more time observing.
One word to describe my dog would be manipulative. When my family eats at the dinner table, he begs and paws at our feet, testing each f us to identify the weakest link. Eventually, he notices patterns - he's more likely to get food from my mom than from my brother, for example. So he'll stick by mom's side during dinner because he knows the probability of getting food is higher. My mom tends to pamper Columbus more than my dad - so when my dad picks up the towel to give Columbus a bath and my whole family is sitting on the couch, he makes a beeline to my mom for protection.
4) Is your dog more like a cat?
There is a saying that "cats are smarter than dogs" - they do what they want, and are known to "own their human owners." It isn't entirely false - a cat's brain has almost double the amount of neurons than in a dog's brain. They focus on perceiving and observing...and sleeping. Columbus knows which human to go to depending on what he needs - if he needs to go out, he'll go to my dad. If he wants food, he'll go to my mom. If he wants to play with his toy, he'll go to me or my brother. Sometimes he'll come when called but it really depends on how he feels - if he's too comfortable in bed, he won't move - and he knows he won't get punished for it. Now when you're you're wondering: "how intelligent are dogs?" who don't listen to you, you'll think back on Columbus. So... maybe your dog isn't lazy, just smart enough to work the system!