Dogs understand social cues from early age, study finds

By our side for thousands of years, dogs are masters of understanding human communication. A new study finds their ability to understand social cues emerges from an early age — without much training — and that genetics plays a key role.

Why it matters: The findings suggest human preferences for communication may have shaped the domestication and evolution of one of our best animal friends. It could also help researchers to understand dogs' social cognition — and how it compares to humans.

• The dogs' abilities to evaluate social cues were similar to humans — and appear to be more sophisticated than chimpanzees and bonobos, our close social relatives.

What they did: Some 375 8-week-old golden and Labrador retriever puppies or a mix of the two breeds, which were bred to be service dogs and had spent most of their lives at that point with their littermates, were given a range of cognitive and behavioral tests to assess their responses to human gestures, speech and interaction.

• Some of the puppies used pointing and gazing from humans to successfully complete the task of finding a treat hidden under a cup, starting with their first trial, researchers led by Emily Bray of the University of Arizona, Tucson, and Canine Companions for Independence report today in the journal Current Biology. Their performance didn't improve over 12 trials, indicating they weren't learning over time.
• Speech was important, too: Experimenters had to initiate the interaction with the dog using a high-pitched voice.

Knowing the pedigree of the puppies, the researchers then tried to tease out whether genetics played a role in the differences in the individual puppies' abilities.

• They found more than "40% of the variation in dogs’ point-following abilities and attention to human faces was attributable to genetic factors." (Other abilities — including the tendency to approach the experimenter or to use a marker placed next to a cup to indicate the food — were less heritable.)

What's not known ... the cognitive mechanisms dogs use to follow these cues and the specific genes that are implicated in playing a role in these social behaviors, says Bray.

What they're saying: Scientists have long debated whether the ability of dogs to follow human social cues was innate or learned.

• The new study suggests dogs have innate skills and that the ability to follow social cues was actively selected by humans in early dog domestication, says Zachary Silver, a graduate student at Yale University who studies domestic dogs and their communication and wasn't involved in the research.

The big picture: "We don’t know of other species that, without extensive exposure, can successfully interpret the cues of a different species," Silver says of dogs.

• "That says something interesting and important about dogs' domestication that they can communicate with their own species and others."