There’s a reason wolves aren’t man’s best friend. Unlike dogs, untrained wolves don’t understand our gestures (like pointing), they don’t stare lovingly into our eyes, and—of course—they don’t play fetch. But dogs’ highly sociable nature carries a cost, according to a new study: It makes them less able to solve problems on their own.
The large social gulf between wolves and dogs is best seen in the following experiment: Teach both species how to open a container to get a treat and then seal the container so that it can’t be opened. Faced with such an impossible task, dogs quickly look back at their owners, as if asking for help. But wolves generally continue to work on the problem, apparently refusing to accept that it can’t be solved. And they rarely look to a human for assistance.
“People tend to think that dogs are clever because they recognize when a problem is unsolvable, whereas wolves don’t seem to understand this,” says Monique Udell, an animal behaviorist at Oregon State University, Corvallis, and the author of the new paper. But what happens when the two species are presented with a puzzle that—with a little persistence—can be solved?
To find out, Udell presented 10 pet dogs and 10 wolves raised by people with a task that could be readily solved. Ten dogs from a shelter were also included to represent canines at a sort of midpoint: not as socially sensitive as pets, but not as human-adverse as wolves. An experimenter (the dog’s owner in the case of the pets) called each animal, and allowed it to sniff a bit of sausage. He or she next placed the meat inside a clear plastic container and snapped on a lid, from which a short piece of rope extended. The dog or wolf had only to pull on the rope while holding down the box to get the treat.
In one test, each animal was left alone after being given the box. In another, the experimenter stayed nearby. Each test lasted 2 minutes. When alone with the puzzle, eight of the wolves readily opened the box (as one is doing in the video below), but only one of the shelter dogs succeeded. None of the pet dogs got the box open. The results were similar when a person was present. Again, eight of the wolves solved the problem, but only one of the pet dogs and none of the shelter dogs did. All the dogs spent significantly more time looking at the human than the wolves did.
The nine pet and nine shelter dogs that failed to solve the puzzle box were then given another chance. This time, the human gestured and spoke to them encouragingly, urging them to keep at it. Four of the shelter dogs were then able to solve the puzzle, but only one pet dog managed to do so. Still, all the dogs spent much more time working on the puzzle box than they did in the other tests, Udell reports online today in Biology Letters.
The results show that even when faced with a puzzle that is easily solved (instead of unsolvable), wolves and dogs use different strategies, Udell says. The wolves were bent on figuring out the solution by themselves, whereas the dogs generally made no effort to work on the puzzle until someone encouraged them—and even then they were oddly unsuccessful. “It’s not that dogs can’t do it,” Udell says. “But they don’t even try unless they’re socially motivated.”
The difference, she suspects, stems from how we raise dogs. “We tell them not to do things, so they learn to inhibit their actions and to wait for directions from us.” Dogs that don’t learn these lessons may end up in shelters.
She is uncertain why during the encouragement tests the shelter dogs were more successful than the pets at solving the puzzle. “The pet dogs seem to err on the side of caution, even though solving the problem independently would be fine, and their owner is telling them that it’s okay,” she says. “They prefer a social cognitive solution”—that is, they want their owner to help them open the box.
Dogs’ preference for a social solution does not mean that they are less intelligent than wolves, stresses Brian Hare, an evolutionary anthropologist at Duke University in Durham, North Carolina. “It’s adaptive for wolves to be independent problem solvers, and for dogs to read human [cues].” He suspects that the breed of dog also matters on these tests, because another recent study showed that more energetic dogs have more trouble inhibiting their behavior.
It’s also difficult to determine whether the dogs and wolves were equally motivated to solve the puzzle, says Zsófia Virányi, an ethologist at the Wolf Science Center in Ernstbrunn, Austria. All the animals approached the box in less than 2 seconds, but only the wolves persisted in working on the puzzle. Virányi, who has raised both dog and wolf puppies from little more than a week old, wonders if the wolves kept at it simply because “they were more food motivated than the dogs.”
Or it may be, as Udell also suggests, that the dogs simply had never had as many opportunities as the wolves to solve problems because people were always there to help. The dogs had only to turn their heads and look back.