Do dogs detect deception?

Mark Petter and his dog Duenna. (Danny Abriel Photo)

With those big brown eyes, you might figure your dog knows what you’re thinking. With a dismissive sniff, she’s telling you she knows when your cry of “treats!” is really a hoax to get her back in the house.

But does she really? Can dogs understand deception?

Mark Petter, a Dalhousie PhD student in clinical psychology, wanted to find out whether dogs could recognize if humans had the intention of deceiving them. Research he conducted as an undergraduate student at the University of Western Ontario has just been published in the October issue of Behavioural Processes, a journal dedicated to high-quality original research on animal behaviour.

The results showed that dogs didn’t differentiate between the human “cooperators” or “deceivers” to a remarkable degree.

“We thought they’d be better at it because dogs seem to be so sensitive to social cues from humans,” says Mr. Petter, a dog lover all his life. Through the interview, his dog Duenna lies at his feet and perks up at the mention of her name. “But there’s no evidence dogs can understand the intentions of a deceiver, nothing that told us the dogs thought, ‘hey this person is deceiving me, I shouldn’t listen to them.’”

In the experiments, dogs were allowed to choose between two containers, one of which contained a food reward. A cooperative human tester stood behind and pointed to the baited container on half the trials, and a deceptive human tester pointed to the empty container on the other half of the trials. While the dogs approached the cooperator more often than the deceiver, the difference was not significant enough to indicate an understanding of the intentions of the deceiver. “They had a lot of time to learn what was going on, but they never really picked up on it,” says Mr. Petter.

In comparison, studies done with apes revealed the apes could differentiate between cooperators and deceivers: “Most apes learned to never approach the person who was lying to them, and even learned to deceive the humans.”

For centuries, dogs have been valued by their humans for their trusting, loyal natures, which may explain why they’re so lousy at figuring out when someone’s trying to trick them. But Mr. Petter says the experiments didn’t differentiate between breeds and it’s possible that some breeds would fare better at the experiments than others.

Since coming to Dalhousie to do graduate work in chronic disease a few years ago, the Ontario native figured his research with dogs was behind him. But maybe he was deceiving himself?

He’s now researching whether owning a dog helps people recover and maintain their health after undergoing a life-changing experience, such as heart surgery.

“Do dog owners exercise more? Are they able to maintain higher physical activity levels over the course of the year?” asks Mr. Petter, 27. “Something tells me if you’ve got a dog at the door with its leash in its mouth, that that may have an affect on whether you go for a walk.”