Can Dogs Tell When We're Lying to Them?

Source: Irene Castro/Shutterstock

It's well known that dogs read humans very well, including reading our faces and different facial expressions and letting us know when we're angry when we may be unaware of it. And now, in a new study by Lucrezia Lonardo and her colleagues at the University of Vienna titled Dogs Follow Human Misleading Suggestions More Often When the Informant Has a False Belief, we know dogs can read situations when humans are lying and being deceptive.¹

An excellent summary of the research can be found in a piece published in New Scientist by Christa Lesté-Lasserre called "Dogs Will Ignore You if They Know You Are Lying, Unlike Young Children." It actually was the title of Lesté-Lasserre's essay that caught my attention because of its clear and to-the-point title.

To conduct their study, the researchers wrote:

We investigated whether dogs (Canis familiaris) distinguish between human true (TB) and false beliefs (FB). In three experiments with a pre-registered change of location task, dogs (n = 260) could retrieve food from one of two opaque buckets after witnessing a misleading suggestion by a human informant (the 'communicator') who held either a TB or a FB about the location of food.

In this creative study, the dogs were first trained to find food hidden in one of two covered bowls and to follow the advice of an unfamiliar human (the communicator). During the familiarization phase, when the communicator touched the bowl in which the food was located, looked at the dog, and said, "Look, this is good, this is very good," the dogs came to trust them.

In the second set of experiments, dogs watched another person move the food from the first bowl to another bowl in two situations: (1) the communicator was present, saw what was happening, and knew the food had been moved from the original bowl; and (2) when the communicator wasn't there, didn't see the switch, and thought the food was still in the original bowl. The important point in these experiments was that the original dog bowl was now empty, and the dogs knew that the communicator either saw the switch or didn't see it, so either they were telling the truth when they told the dogs where the food was, or they were lying about the location of the food.

Dogs Know When We’re Telling the Truth and When We’re Not

The results of this study are fascinating. The researchers wrote, "On average, dogs chose the suggested container significantly more often in the FB group than in the TB group and hence were sensitive to the experimental manipulation."

Around 66 percent of the dogs trusted the honest suggestions of false-believing communicators who hadn't seen the food being moved. In contrast, only about 50 percent of the dogs followed the misleading advice of communicators lying because they knew the food wasn't in the original container.

All in all, this research showed that at least some dogs know when we're telling the truth and when we're not, and perhaps many, if not most dogs, can also differentiate honest mistakes from outright lies in this and other contexts. I would love to know how they do it. For example, are they using visual or olfactory cues or a composite signal combining information from these or other indicators we are unaware of? Or perhaps they simply remember what humans have done and are saying something like, "Hey, you're lying to me, and I don't believe you!"

As we learn more and more about the cognitive capacities of homed canine companions and free-ranging and feral dogs, it will serve them and us well in practical, on-the-ground ways and hopefully foster better dog-human relationships, a win-win for all.

Facebook/LinkedIn image: Irene Castro/Shutterstock