"The next time you start shaking your finger and shouting 'Shame on you!' because your dog chewed up your favorite fuzzy slippers, just remember that no matter how guilty your dog looks, it doesn't know what your rant is about. Behaviorists insist dogs lack shame. The guilty look — head cowered, ears back, eyes droopy — is a reaction to the tantrum you are throwing now over the damage they did hours earlier."
Canine Con Jobs