Cubs shock researchers by retrieving balls just like dogs - proving it's a natural instinct and NOT 15,000 years of training

It was thought dogs only played fetch thanks to thousands of years of domestication, but a new study has found that even wolf pups will run for a ball. 

Researchers from Stockholm University, Sweden made the serendipitous discovery during an unrelated behavioural test on 13 wolf puppies from three different litters.

The research suggests the ability to interpret human social cues to catch a ball and bring it back also exists in modern wolves and may be innate to all canine species.

In one test, three eight-week-old wolf puppies spontaneously showed interest in a ball and returned it to a perfect stranger upon encouragement.  

Researchers said the discovery was a shock as it was previously thought the ability to follow human cues only developed after domestication 15,000 years ago.

They thought that dogs only developed the ability to fetch a ball thanks to millennia of humans selectively breeding only those canines able to respond to commands. 

'When I saw the first wolf puppy retrieving the ball, I literally got goosebumps', said study author Christina Hansen Wheat from Stockholm University.

'It was so unexpected, and I immediately knew that this meant that if variation in human-directed play behaviour exists in wolves, this behaviour could have been a potential target for early selective pressures exerted during dog domestication.' 

The team raise wolf and dog puppies from the age of 10 days and put them through various behavioural tests to understand how domestication affects behaviour. 

In one of those tests, a person the pup does not know throws a tennis ball across the room and, without the benefit of any prior experience or training, encourages the puppy to get it and bring it back.