Dogs often seem to be psychic, anticipating what we're going to say or do, and now research reveals one secret behind this canine ESP: Dogs intensely track our eye movements, which can be tied to intent.
Human babies also possess the ability, described in the latest Current Biology. The discovery might help to explain why so many people treat their furry pals like their kids.
"Dogs are receptive to human communication in a manner that was previously attributed only to six-month-old human infants," co-author Jozsef Topal told Discovery News.
"They read our intention to communicate in a preverbal, infant-like manner," added Topal, who works in the Institute for Psychological Research at the Hungarian Academy of Sciences.
For the study, Topal and his colleagues presented dogs with video recordings of a person turning toward one of two identical plastic pots while an eye tracker captured information about the dogs' reactions.
In one test, the person looked directly at the dog, addressing it in a high-pitched voice with "Hi dog!"
In the second test, the person gave only a low-pitched "Hi dog" while avoiding eye contact.
The study determined that dogs were more likely to follow along and look at the pot when the person first expressed an intention to communication.
While dog-lovers the world over have likely suspected that their pets have such talents, the experiment is actually the first to ever use eye-tracking techniques to study canine social skills.
The researchers say that dog social skills reach the level of a two-year-old human, since the only talent that's missing is language.
"Although dogs might use a different cognitive architecture for processing human communication, they can play the role of being a child substitute," Topal said.
"These skills on the part of the dog help to make the human-dog bond stronger, which is actually unique when taking into account the biological differences between the two species."
Dogs were the first animals to be domesticated and for no apparent direct benefit, such as for food or herding, explained Topal. Dog social cognition has evolved over thousands of years, during which time wolf-like capabilities were transformed by the challenges of living with humans.
Topal and his team suspect that horses and domesticated cats may also be able to read human intent, since they too have lived closely with us for many years.
Dogs may be the most perceptive, however.
"Dogs are in a special way tuned in to humans," Topal explained. "They are interested in finding out how we think, and they are able to do it by reading our subtle communicative behaviors."
In a separate new study published in the journal Animal Behaviour, researchers discovered that dogs communicate with humans to request, but not to inform. Nevertheless, the process is still very focused and intense.
We show "how much dogs are tuned into the intentional dimension of human communication and how important certain signals are for them to know when communication is relevant and directed at them," said Juliane Kaminski, lead author of the paper and a researcher in the Evolutionary Roots of Human Social Interaction group at the Max Planck Institute for Evolutionary Anthropology.
Topal thinks it's possible that dogs are even sometimes better than adults are at reading human intent, given that they are so attuned to smells, sounds, and other cues.
"They can easily learn to associate even unconscious behavioral cues of their owner with particular consequences," he said. "This way, a dog can acquire an ability to anticipate the owner's behavior, and this may give a false impression of mind-reading."