Dogs can understand our intent to communicate with them and are about as receptive to human communication as pre-verbal infants, a new study shows.
Researchers used eye-tracking technology to study how dogs observed a person looking at pots after giving the dogs communicative cues, such as eye contact and directed speech. They found that the dogs’ tendency to follow the person’s gaze was on par with that of 6-month-old infants.
The study suggests that dogs have evolved to be especially attuned to human communicative signals, and early humans may have selected them for domestication particularly for this reason, the researchers said.
Other scientists are excited that the eye-tracking method has been successfully adapted for dogs. “This opens many new opportunities in studying dog cognition,” said Juliane Kaminski, a cognitive psychologist at the Max Planck Institute for Evolutionary Anthropology in Germany, who was not involved in the research.
“The research was motivated by the infant scientific literature,” said study first author Erno Teglas, an infant psychologist at the Central European University in Hungary. The researchers essentially conducted the same experiment with dogs that other scientists did with infants in 2008.
For their study, Teglas and his colleagues tracked the eye movementsof 16 untrained adult dogs during two different trials. The dogs watched a series of movies in which a woman turned her attention toward one of two identical containers — one on her left and one on her right — after addressing the dogs in an “ostensive” or “non-ostensive” manner.
Ostensive signals, Teglas explained, convey the intention of communication. “You’re saying to the dog: ‘You are addressed and not someone else, and now I am going to tell you something that’s relevant or important to you,’” he told LiveScience.
To convey her intent to communicate in the first trial, the woman in the video made eye contactwith the dogs and then said, “Hi dog!” in a high-pitch, motherly tone (or “doggerly tone,” as Teglas describes it). In the second, non-ostensive, trial, the woman didn’t look at the dogs at all and said, “Hi dog,” in a low-pitch tone, as if she were speaking to another adult.
The researchers found that the dogs spent a similar amount of time looking toward the woman and scanning her face in both trials. However, the dogs spent more time looking at the same container as the woman in the ostensive trials compared with the non-ostensive trials.
The results indicate that, like infants, dogs are sensitive to cues that signal a person's intent to communicate useful information, Teglas said, though it’s unclear if certain breeds are better at reading communicative signals than others. [10 Most Popular Dog Breeds]
A special adaptation
Kaminski says that the study fits in with other research (including her own) showing that dogs are aware of the "intentional dimension of communication," a skill that may be a special adaptation unique to dogs.
"There is no other species which is so responsive to communicative cues coming from humans," Kaminski wrote in an email to LiveScience. "Not even apes, as humans' closest living relatives, have the same sensitivity to human communication."
Teglas notes that previous research has shown that wolves, dogs' closest living relatives, are not as adept as dogs at following human gestures to find food or other rewards (in fact, puppies will do better than adult wolves, unless the wolves were specially trained).
One question still remaining, Teglas said, is which communicative cue — eye contact or directed speech — is more important. "One should think that one of the cues might be more relevant," he said. "There might even be different kinds of animals that respond to different kinds of cues."
The research was published today (Jan. 5) in the journal Current Biology.