Guilty as Charged?
Guilty, you say? Or is it something else?
Guilt is a human emotion, not a canine emotion. Dogs have no moral concept of good or bad and therefore can't feel guilt. So, no matter how guilty you think your dog looks, he isn't feeling guilt at all.
So, what exactly is your dog feeling? And why do we think he looks guilty?
Let's say your dog loves to steal food from counters. You correct him, but stealing the roast from the counter is a big reward. It is up to your dog to decide if the reward is worth the punishment. You see Shadow gnawing on the bone and start yelling. Shadow cringes. He averts his eyes. He acts "guilty."
He's not feeling guilty, and he's not really acting guilty either; he is acting submissive because you're angry. As you know, dogs are descendants of wolves. When the lead wolf in a pack (called the alpha) gets angry at another wolf, the lower wolf becomes submissive. This includes averting his gaze, cowering and licking nervously. The alpha growls until he's satisfied that the pack member is submissive enough.
When you growl (yell, punish, etc.), you've become that alpha. Hence, the submissive behavior toward you. Although I don't advise it, you can also elicit the same response by pointing your finger at your dog and telling him he's a bad dog.
Dogs don't feel guilty, but they do react submissively to your anger. They don't think about right or wrong, good or bad. They do think about whether or not the leader is angry. Sometimes they even anticipate your anger, based on your body language or on your usual patterns of behavior. For, example, if you yell at your dog when you come home for his occasional lapses in behavior, he is going to assume that you will yell at him every time you come home. He associates the yelling with you coming home, not with anything that he did.
So keep that in mind when you leave that roast on the counter for Shadow to snitch.