Dogs Have Unusual Ability to "Read" Humans,
According to Research Published in Science

Domesticated dogs first appeared in East Asia, spread across Asia and Europe, and then accompanied their two-legged companions into the New World 12,000-14,000 years ago according to research published in the 22 November 2002 issue of Science. That's the scenario pieced together by two research teams, which traced the genetic origins of New and Old World dogs. A third study comparing some modern dog and wolf behaviors suggests that, during the domestication process, dogs developed the unusual ability to read certain social cues from humans.

Humans may have domesticated dogs from wolves as recently as 15,000 years ago, according to the study on Old World dogs by Peter Savolainen and colleagues. The Swedish and Chinese researchers analyzed DNA samples taken from dogs in Asia, Europe, Africa, and arctic America. They found that, while most dogs shared a common gene pool, genetic diversity was highest in East Asia, suggesting that dogs had been domesticated there the longest. Previously, researchers had generally looked to the Middle East as the setting for domestication of plants and animals, according to Savolainen.

A second international research team investigated whether dogs in the New World were domesticated from wolves there, independently from Old World dogs, or whether the two groups were related. Jennifer Leonard and colleagues compared DNA sequences of New and Old World dogs, including some Latin America and Alaskan dogs that pre-dated the first European explorers in the Americas. The similarities among the sequences indicated that all the dogs shared a common ancestor. A certain cluster of sequences from ancient Latin American dogs didn't match any from modern dogs, indicating that European colonists probably did not use Native American dogs to create the breeds that we know today, according to the authors.

Unlike wolves and chimpanzees, adult dogs and puppies are unusually skillful at reading signals from human indicating the location of hidden food, according to a third study. This ability may therefore have emerged during domestication, Brian Hare and colleagues propose, either as the result of intentional selection by humans or as a byproduct of the domestication process. Although more work will be necessary to confirm this, the authors suggest that dogs may be able to think about the thoughts of others, which thus far only humans and possibly some non-human primates are known to do. The authors compared dogs', wolves', and chimpanzees' ability to find food hidden in one of two containers after an experimenter had reached toward, gazed at, or marked the baited containers. The fact that dogs of all ages out-performed the other animals indicates that being able to read human social cues is neither common to all canids or the result of exposure to humans, the authors say.

—Kathy Wren

21 November 2002