I think we all know the situation. We come into a room and there is a mess on the floor. Maybe a poo or pee accident, or maybe the dog got into the garbage. As we look over the mess the dog slinks away or holds their head down. Maybe we ask "did you do this?" and the dog looks away. It's pretty obvious that the dog knows what they did wrong and that they are feeling guilty about it.
Or do they?
It's pretty easy to find videos online of "guilty" dogs. Check out a couple of these...
It seems pretty clear that these dogs recognize their bad deeds and feel some degree of guilty. However, studies have shown that this isn't the case, and we are attributing too many human emotions to our pets.
A dog has little to no long-term association between their behaviors and either punishment or reward. Behavioral studies have shown that a positive or negative reinforcement must happen within 20 seconds or a dog doesn't associate it with whatever action they performed. For example, say that you let your dog out to go to the bathroom, they potty and then wander around the yard for a minute or so. They come back to the door and you praise them for being such a good dog and going potty. However, it's been too long for the dog to link the bathroom behavior and the praise, so they believe that they are being rewarded for coming to the door (the most recent behavior prior to the reward). Similarly, if you come home and find a mess, the dog only reacts to the mess on the floor, not to the fact that they created it.
It's a subtle but important difference. There was a study that looked at dogs in homes. When the dog was out of the room a person turned over a trashcan just like a dog might have done, and then the dog was let back into the room. When the dog saw the mess, it acted "guilty". So why did it do so?
Think about the time period for reward or punishment. If you come home and find a mess, you are likely to get upset. Even if you don't spank or hit the dog (which you should never do), or yell at the dog, your pet can recognize the tension and anger in your body language. When a pack leader shows signs of anger or aggression it's a typical dog reaction to start showing submissive behavior: lowered head and tail, keeping the body low to the ground, avoiding eye contact, and so on. Though we interpret these behaviors as "guilt", it's really signs of submission. The dog is making a connection between a mess on the floor and your angry behavior. They are NOT making a connection between their behavior and your anger. When you come home their action was far enough in the past (more than 20-30 seconds) that they don't associate it with any of your actions. In a dog's mind it goes like this: "Mess is on the floor. My person gets upset when there is a mess on the floor, and I have experiences in the past that show this is consistent. When there is a mess on the floor and my person is in the room, I know they are going to be upset. When these conditions happen together, I need to act submissive to help defer any anger from me."
So dogs really don't feel "guilty". This is another example of how people and pets often speak in different "languages". The dog is trying to communicate in the only "language" that they know, and are expecting us to understand. We, however, misinterpret the language in our own, sometimes coming to the wrong conclusions.