New Delhi, Dec 9 (IANS) Scientists in Austria have found a basic form of jealousy in dogs, BBC reported.
The Vienna-based researchers showed that dogs will stop doing a simple task when not rewarded if another dog, which continues to be rewarded, is present.
Writing in the journal PNAS, the scientists say this shows a sensitivity in dogs that was only previously found in primates.
The researchers now plan to extend their experiments to look at co-operative behaviour in wolves, the report said Monday.
The experiment consisted of taking pairs of dogs and getting them to present a paw for a reward. On giving this 'handshake' the dogs received a piece of food.
One of the dogs was then asked to shake hands, but received no food. The other dog continued to get the food when it was asked to perform the task.
The dog without the reward quickly stopped doing the task, and showed signs of annoyance or stress when its partner was rewarded.
To make sure that the experiment was really showing the interaction between the dogs rather than just the frustration of not being rewarded, a similar experiment was conducted where the dogs performed the task without the partner. Here they continued to present the paw for much longer.
Frederike Range from the department of neurobiology and cognition research at the University of Vienna, says this shows that it was the presence of the rewarded partner which was the greater influence on their behaviour.
'The only difference is one gets food and the other doesn't, they are responding to being unequally rewarded.' she said.
The researchers say this kind of behaviour, where one animal gets frustrated with what is happening with another, has only been observed in primates before.