Now a study from Japan suggests that dogs can tell when a human is trying to dupe them.
"Dogs have more sophisticated social intelligence than we thought," Dr. Akiko Takaoka, a researcher at Kyoto University and a co-author of the study, told the BBC. "This social intelligence evolved selectively in their long life history with humans."
For the study, which was published Oct. 24, 2014 in the journal Animal Cognition, the researchers tested 34 pet dogs as they interacted with a human and a pair of containers (one containing a food treat, the other empty).
In the first phase of the study, an experimenter pointed at a container that held a treat--essentially giving good advice. In the second phase, the experimenter showed the dogs the contents of both containers and then pointed to the empty container. In phase three, the experimenter pointed once again at the treat-filled container, just as in phase one.
What happened? The dogs were much less likely to heed the experimenter's guidance in phase three than in phase one. That suggests that they can tell when we mess with them--and know not to be too trusting.
As the researchers wrote in the abstract of the study, "These results suggest that not only dogs are highly skilled at understanding human pointing gestures, but also they make inferences about the reliability of a human who presents cues and consequently modify their behavior flexibly depending on the inference."