Image: Dogs
Friederike Range  /  AP
The dog on the left has not received food for giving the paw in the last trials and observing that the partner (right) did receive food, the subject is refusing to give the paw and avoids looking at the experimenter.
By
updated 12/8/2008 11:23:36 AM ET 2008-12-08T16:23:36

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, Austria, 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.

When both got a reward all was well.

One thing that did surprise the researchers was that — unlike primates — the dogs didn't seem to care whether the reward was sausage or bread.

The 10 smartest animalsPossibly, they suggested, the presence of a reward was so important it obscured any preference. Other possibilities, they said, are that daily training with their owners overrides a preference, or that the social condition of working next to a partner increased their motivation regardless of which reward they got.

And the dogs never rejected the food, something that primates had done when they thought the reward was unfair.

The dogs, the researchers said, "were not willing to pay a cost by rejecting unfair offers."

Clive Wynne, an associate professor in the psychology department of the University of Florida, isn't so sure the experiment measures the animals reaction to fairness.

"What it means is individuals are responding negatively to being treated less well," he said in a telephone interview.

But the researchers didn't do a control test that had been done in monkey studies, Wynne said, in which a preferred reward was visible but not given to anyone.

In that case the monkeys went on strike because they could see the better reward but got something lesser.

In dogs, he noted, the quality of reward didn't seem to matter, so the test only worked when they got no reward at all, he said.

However, Wynne added, there is "no doubt in my mind that dogs are very, very sensitive to what people are doing and are very smart."

© 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Photos: Animal Tracks: Aug. 4  - Aug. 11

loading photos...
  1. Chimp off the old block

    Shiba, a chimpanzee at Sydney's Taronga Zoo, holds her newborn baby on Aug. 10. (Lisa Ridley / AFP - Getty Images) Back to slideshow navigation
  2. Cow caress

    Emma Leis lays on a cow at the Wisconsin State Fair in West Allis, Wisconsin, on Aug. 9. (Jim Young / Reuters) Back to slideshow navigation
  3. When pigs flee

    Pigs race at the Wisconsin State Fair in West Allis, Wisconsin, on Aug. 9. (Jim Young / Reuters) Back to slideshow navigation
  4. Dog takes catnap

    A 29-day-old Labrador puppy sleeps against a tree at a courtyard in Beijing on Aug. 10. (Jason Lee / Reuters) Back to slideshow navigation
  5. Busy bee

    A bee gathers nectar along Skyline Drive in Shenadoah National Park in Virginia on Aug. 9. (Karen Bleier / AFP - Getty Images) Back to slideshow navigation
  6. Bright butterfly

    An eastern tiger swallowtail butterfly flies in Shenadoah National Park in Virginia on Aug. 9. (Karen Bleier / AFP - Getty Images) Back to slideshow navigation
  7. Seeing double

    A gorilla is reflected in a window at the Hellabrunn Zoo in Munich, Germany, on Aug. 8. (Sven Hoppe / AFP - Getty Images) Back to slideshow navigation
  8. Blooming plumage

    A peacock displays his plumage at the Hellabrunn Zoo in Munich, Germany, on Aug. 8. (Sven Hoppe / AFP - Getty Images) Back to slideshow navigation
  9. Rock on

    A 9-month-old baby samang, a tailless, black-furred gibbon native to forests in Malaysia and Indonesia's Sumatra province, holds onto a rock during a Hindu ritual ceremony in Bali, Indonesia, on Aug. 9. (Firdia Lisnawati / AP) Back to slideshow navigation
  10. Sitting pretty

    Parrots look around at the ZOOM zoo in Gelsenkirchen, Germany, on Aug. 8. (Patrik Stollarz / AFP - Getty Images) Back to slideshow navigation
  11. Meerly looking

    A meerkat stands and watches visitors at the ZOOM zoo in Gelsenkirchen, Germany, on Aug. 8. (Patrik Stollarz / AFP - Getty Images) Back to slideshow navigation
  12. At the end of their rope

    Pig-tailed macaques climb on a rope at the ZOOM zoo in Gelsenkirchen, Germany, on Aug. 8. (Patrik Stollarz / AFP - Getty Images) Back to slideshow navigation
  13. The eyes have it

    A snow owl at the ZOOM Zoo in Gelsenkirchen, Germany, on Aug. 8. (Patrik Stollarz / AFP - Getty Images) Back to slideshow navigation
  14. On the prowl with a growl

    A tiger walks around at the ZOOM zoo in Gelsenkirchen, Germany, on Aug. 8. (Patrik Stollarz / AFP - Getty Images) Back to slideshow navigation
  15. Big bad wolf

    Chingiz, a male Siberian forest wolf, walks around inside an open-air cage at the Royev Ruchey Zoo in Russia on Aug. 8. (Ilya Naymushin / Reuters) Back to slideshow navigation
  16. Washing up

    Masha, a female raccoon, holds a piece of cloth in a pan with water, placed by zoo employees, at the Royev Ruchey Zoo in Russia on Aug. 8. (Ilya Naymushin / Reuters) Back to slideshow navigation
  17. Teeny turtle

    A zoo worker holds a newborn river terrapin on display at Dusit Zoo in Bangkok on Aug. 8. The River Terrapin is one of the most critically endangered turtle species. (Pornchai Kittiwongsakul / AFP - Getty Images) Back to slideshow navigation
  18. Lengthy lick

    A giraffe licks its face at the Philadelphia Zoo on Aug. 7. (Michael Zorn / Getty Images) Back to slideshow navigation
  19. National bird

    An American bald eagle surveys its surroundings at the Philadelphia Zoo on Aug. 7. (Michael Zorn / Getty Images) Back to slideshow navigation
  20. Silly seal

    A young seal emerges from the water in Friedrichskoog, Germany, on Aug. 7. (Daniel Bockwoldt / DPA via AFP - Getty Images) Back to slideshow navigation
  21. Leaving the hospital

    Crowds of beach goers watch Mitchell, a 65-pound juvenile loggerhead sea turtle, crawl back to the ocean during the release of rehabilitated sea turtles on Aug. 6 in Isle of Palms, South Carolina. The turtle which accidentally swallowed a fishing hook and had it surgically removed by the sea turtle hospital at the South Carolina Aquarium in Charleston. (Richard Ellis / Getty Images) Back to slideshow navigation
  22. Pampered pachyderms

    An elephant keeper sprinkles coconut oil on orphaned elephants at the David Sheldrick Elephant Orphanage within Nairobi National Park in Kenya on Aug. 6. (Thomas Mukoya / Reuters) Back to slideshow navigation
  1. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  2. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  3. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  4. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments