WASHINGTON, D.C.—Since they split from wolves, domestic dogs have changed in many ways. Unlike their wild ancestors, they're comfortable around humans, pay close attention to us, and follow orders—at least sometimes. That social intelligence is critical to making a dog man's best friend. But research presented here last week at the annual meeting of the Association for Psychological Science shows that dogs may have also lost some of their social smarts in the process.
One of the classic experiments that shows the cognitive difference between wolves and dogs is the pointing task: Whereas a dog—even a 3-month-old puppy—will readily follow the direction a person points in, wolves just don't get it. That contrast has been cited as evidence that dogs may have gained social intelligence not present in wolves. "But that story is too simple," says Friederike Range, a behavioral biologist at the University of Veterinary Medicine Vienna.
To dig deeper, Range and her colleague Zsófia Virányi studied a captive population of wolves and dogs raised together at the Wolf Science Center outside Vienna. For one thing, they found that wolves work together better than dogs do. For example, in one set of experiments that have not been published, Range and Virányi observed the behaviors of groups of wolves or dogs sharing a common food source provided by researchers. Although there was more aggression among wolves—from muzzle-nipping to growling—every wolf, even the lowest ranked, was able to negotiate a share of food. Dogs are less aggressive with one another, but the food-sharing is far from collaborative. "The alpha dog monopolizes the food source and lower ranked dogs just stay away," Range says. Those differences made Range and Virányi wonder: Perhaps scientists who compare the social intelligence of wolves and dogs have been barking up the wrong tree. Dogs may be better at learning from humans, but what about from other dogs?
To test how well dogs and wolves could learn from one another, the researchers created a problem that wolves and dogs were equally motivated to solve: a food treat locked inside a box. The only way to open the box was with a lever. They trained one dog to operate the lever with its mouth, and another dog to use its paw. (The wolves were raised with the dogs and treated them as members of the same pack, Range says.) Then they let wolves and dogs see the box opened by one of those two methods. If dogs have better social intelligence across the board, they should do better than the wolves at learning by example and getting at the treat.
But the dogs did poorly, Range reported at the meeting. Only four out of 15 managed to open the box at all, and none used the method (mouth or paw) that they had been shown. Meanwhile, all 12 of the wolves got the treat, and nine of them did so by copying the method they had been shown. "The mainstream theory is that wolves became dogs when they started treating humans as their pack members," Range says. Rather than gaining new cognitive abilities that wolves never had, such as so-called "theory of mind" required to learn complex tasks by watching others perform, dogs may have undergone an evolutionary tradeoff: losing some of the ability to learn from their own kind, but gaining the ability to learn from humans.
The jury is still out on whether dogs have lost a mental ability. "What we need to see next is the same experiment but with humans teaching the dogs and wolves," says Timothy Bates, a psychologist at the University of Edinburgh in the United Kingdom. It may be that dogs have grown worse at learning, but "it could be that dogs just pay attention only to humans now." Range says that she has done the experiment to test that difference and is analyzing the data now.