Dogs can think 'no fair' too

WASHINGTON -- No fair!

What parent hasn't heard that from a child who thinks another youngster got more of something. Well, it turns out dogs can react the same way.

Ask them to do a trick and they'll give it a try. For a reward, sausage say, they'll happily keep at it.

But if one dog gets no reward, and then sees another get sausage for doing the same trick, just try to get the first one to do it again.

Indeed, he may even turn away and refuse to look at you.

Dogs, like people and monkeys, seem to have a sense of fairness.

"Animals react to inequity," said Friederike Range of the University of Vienna, who lead a team of researchers testing animals at the school's Clever Dog Lab. "To avoid stress, we should try to avoid treating them differently."

Similar responses have been seen in monkeys.

Range said she wasn't surprised at the dogs reaction, since wolves are known to cooperate with one another and appear to be sensitive to each other. Modern dogs are descended from wolves.

Next, she said, will be experiments to test how dogs and wolves work together. "Among other questions, we will investigate how differences in emotions influence cooperative abilities," she said via e-mail.

In the reward experiments reported in Tuesday's edition of Proceedings of the National Academy of Sciences, Range and colleagues experimented with dogs that understood the command "paw," to place their paw in the hand of a researcher. It's the same game as teaching a dog to "shake hands."

Those that refused at the start — and one border collie that insisted on trying to herd other dogs — were removed. That left 29 dogs to be tested in varying pairs.

The dogs sat side-by-side with an experimenter in front of them. In front of the experimenter was a divided food bowl with pieces of sausage on one side and brown bread on the other.

The dogs were asked to shake hands and each could see what reward the other received.

When one dog got a reward and the other didn't, the unrewarded animal stopped playing.