MIkel Delgado, a senior scientist at Purdue University’s School of Veterinary Medicine, has had house cats for most of her life, so she was excited when her new kittens did something her previous cats never did: play fetch. The three cats, sisters adopted from a shelter, all brought her toy mice to throw and then ran to get them.

“It was an interesting surprise,” Delgado said. “It’s very sweet.”

That got her thinking: Was retrieving really such an unusual behavior in cats? So Delgado dug into the research with her Purdue colleagues Judith Stella, senior scientist, and Candace Croney, professor and director of the Center for Animal Welfare Science, and James Serpell of the University of Pennsylvania School of Veterinary Medicine. Using data Serpell had previously collected, they looked at how frequently cat owners reported retrieving and tried to figure out what traits made cats more or less likely to retrieve.

Their analysis found that more than 41% of cats retrieve, compared to about 78% of dogs. In both cats and dogs, younger male cats were more likely to retrieve. Poor health and living with dogs made retrieving less likely in cats and dogs.

The survey data included 8,224 cat owners and 73,724 dog owners.

Some of the results were expected. Certain breeds of dogs are known to be more likely to retrieve, particularly those bred for retrieving or herding tasks – Golden Retrievers, Labrador Retrievers, German Shepherds, etc. – and the team’s analysis confirmed this. These dogs are used to working with people and enjoy the interaction. Breeds that are difficult to train – for example, Great Pyrenees, Chihuahuas and Greyhounds – are less likely to retrieve.

As previous studies have suggested, cat breed also has an influence on retrieving. For example, breeds from the Far East, such as Burmese, Siamese and Tonkinese, retrieve more often than domestic long-haired cats.

“It’s much harder to explain,” Delgado said. Dogs were bred to help humans in various ways, but cats were bred primarily for their looks and companionship.

“Some people say cats have snuck into our hearts without us doing much for them and we haven’t changed them much,” she said. “We don’t ask cats to fetch our slippers, herd sheep or protect our homes.”

One hypothesis is that cats that retrieve are more social, which could explain breed differences. “Siamese cats are very interested in people,” Delgado said.

Indoor cats retrieve much more frequently than outdoor cats. That may be because indoor cats have fewer opportunities to hunt and retrieving scratches the same itch, Delgado said.