Dogs get jealous when given unequal rewards for their faithful obedience, according to a new PNAS paper being mediafied with gusto.

In solo dog-on-human tests, pooches trained to ‘shake hands’ will offer a paw gratis, say researchers at the University of Vienna’s Clever Dog Lab. But if a nearby dog gets a treat for each shake while they go unrewarded, they’ll act upset and refuse to comply.

“Animals react to inequity; to avoid stress, we should try to avoid treating them differently,” said study leader Friederike Range (AP).

The Independent, which clearly spares no expense for doggie mind-reading, concludes: “Canines are capable of withdrawing their co-operation and friendship if they see another dog get tasty sausage morsels that they feel they deserve.” New Scientist goes for the clever-but-inaccurate headline “Jealous dogs don’t play ball”.

The study seems less important for sociobiology than for dinner conversation fodder (watch out for biased distribution of under-table scraps). But the doggy envy is being compared to that of capuchin monkeys, the only other non-humans found to have a sense of equity – Scientific American summarizes this nicely.

The researchers are now rearing wolf pups for further research, to see if domestication causes jealousy. But could there be other influences? “[T]he green-eyed monster which doth mock/ The meat it feeds on” sounds like more of a cat thing to me.

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