Puppies may have more brains than they're given credit for, according to a new study that finds dogs, particularly young ones, are capable of following the direction of a human's voice to find food.
Previous studies had shown that dogs are capable of following a pointed finger or a person's gaze in their quest for treats, and evidence suggests that dogs cue into human emotions (though whether they emphasize with our pain remains an open question). Dogs even beat humans' closest relative, chimpanzees, in understanding human gesture.
Some researchers suspect these talents arose with domestication: Dogs that better understood humans benefited from their close association, and lived to pass down genes that would encourage the human-canine bond. Other scientists suspect these abilities have more to do with a dog's learning over the course of its life. [Canine Secrets: 10 Surprising Facts About Dogs]
In the new study, researchers from the Max Planck Institute for Evolutionary Anthropology in Germany tested a type of communication that has not yet been researched. Instead of using gaze or gesture to indicate food, the experimenters used the direction of their voice.
In the first study, the experimenter stood behind an opaque wooden barrier and secretly placed food in one of two containers in front of the barrier. Twenty-four adult dogs of various breeds participted in the experiment. After hiding the food, the experimenter crouched behind the barrier, out of sight of the canine research subject, and turned his or her face toward the treat-filled container, saying, "Oh, look, look there, this is great!"
The dog's handler then released the dog, and the researchers recorded which box it headed toward.
In an average of 7.6 out of 12 tries, the dogs went right to the food-containing box — even though follow-up experiments proved they could not smell the food, nor were they responding to cues like the experimenter's rustling behind the barrier. When the experimenter directed his or her voice to the back wall instead of toward either container, the dogs could not accurately guess the location of the food.
These results were as good or better than those seen in previous research with human infants, the researchers reported today (May 6) in the journal Proceedings of the Royal Society B.
The first series of experiments made clear that dogs could follow the direction of a person's voice. But was this talent learned or innate?
To find out, the researchers recruited 16 puppies, ages 8 to 14 weeks, and subjected them to the same test. These puppies, being young, had limited training and limited interactions with humans. Nevertheless, they were actually slightly better at following the direction of a person's voice than the adult dogs: The puppies found the food an average of 8.1 out of every 12 tries.
Adult dogs, however, tended to use the voice cue correctly from the beginning, performing just as well on their first try as on their last. Puppies often took a few tries to catch on. The puppies that had experienced more socialization with humans did better than those with limited human interactions.
"It is likely that the skill reported in this study is learned, though very quickly and through a minimal amount of exposure to humans," the researchers wrote.