Both the New York Times and National Geographic reported that dogs have a primitive sense of envy. They describe an experiment on well-trained dogs to offer a paw on command. But when one dog was not given a reward for the obedience, the dog became less and less inclined to obey the command.
I have to agree with the blogger slacktivist, though, that this experiment doesn't seem to point to dogs feeling envy of other dogs receiving rewards. It sounds more like the dogs know a crooked deal when they see one. They've been trained to get a treat as a reward for the unnatural act of offering a paw on command. When the dog stops getting the promised treat, it decides that it doesn't need to obey anymore. If you don't hold up your end of the bargain, why should I bother?
The lead scientist, as reported in Science News, never used the word 'envy' in her description. She calls it what it is, an "aversion to inequity."
Slacktivist wonders why two media outlets would both report the findings as an example of envy, rather than the natural desire to avoid getting a raw deal--something only primates, humans included, have shown before. My interest in the issue is the idea that once again, we see a primitive sense of morality in non-human species. A dog will look at his neighbor getting a reward for the same work and conclude that it doesn't want to cooperate anymore, anymore than a man would work for a company if his coworkers were receiving twice the pay for the same work.
This notion undercuts the idea that there is a huge divide between humans and animals because we are specially created by God. We have souls, say the theologians, and animals do not. Because of those souls, they say, we can commmunicate with God, and we know the difference between right and wrong. And yet dogs, who presumably don't have souls, also have a primitive idea of right and wrong. If I've been trained to get a treat for shaking hands, then it's wrong for me not to get one when I obey the command, particularly if another dog does get the offered treat.
Of course, this does not mean that we evolved our sense of justice from dogs, since we evolved long before dogs ever did. What it shows is that social animals employ certain behaviors to better survive--a sense of fair play one of them. And since we evolved our physical characteristics like opposable thumbs from our primate ancestors, there's evidence that we evolved our sense of morality and proper behavior from them as well.