Among dogs, smarts and friendliness seem to go hand in hand, and this powerful combination is what makes the species such helpful companions. Now, a new study suggests that the two traits really are inseparable, as foxes bred for good nature also develop more social smarts. The findings may solve a long-standing debate about the origin of canine intuition and may provide new clues to the genetics of cognition.
Dogs are even more adept than chimpanzees at interpreting certain human signals such as pointing or gazing. But experts disagree about where this ability came from. Some argue that, in the course of over 10,000 years of domestication, dogs were selected for their cognitive abilities, such as following commands. But others hold that the main trait selected for was friendliness--seeking human company and not biting--and that the cleverness of dogs was an unintended byproduct.
To test the two theories, a team led by Brian Hare, a biological anthropologist at the Max Plank Institute for Evolutionary Anthropology in Leipzig, Germany, visited the Institute of Cytology and Genetics in Novosibirsk, Russia. Here, researchers have been selectively breeding foxes for 45 years: picking foxes that tend not to bite and who are comfortable around humans. Hare's team compared the abilities of tamed and untamed foxes to find hidden food when a human pointed to it.
The results indicate that, when tamed, the farmer's foe is only a few steps away from man's best friend. The tamed foxes were significantly better than their untamed relatives at interpreting a human's pointing and were even as good as domestic dogs of the same age, the team reports in today's issue of Current Biology. To show that this ability is genetic rather than just learned, the team also tried to teach both groups of foxes to interpret pointing. But even with such training, the untamed foxes had no better than a random chance of finding the hidden food. Hare says that, because the foxes were only bred for friendliness, the study lends support to the theory that social cognition in dogs, and perhaps even humans, evolved as a byproduct of selection of unrelated traits.
Ray Coppinger, a cognitive biologist at Hampshire College in Amherst, Massachusetts, says the results are "exciting" but do not yet clinch the mystery of dog cognition. A possible confounding factor, he says, is that the motivation to find food varies between dog breeds and could therefore also vary between the tamed and untamed foxes: Rather than more clever, the tamed foxes might just be hungrier.