Pet owners aren’t the only people who think their dogs are smarter than they actually are. So do the people who study them.

Two researchers in England reviewed more than 300 scientific papers that compared the intelligence of dogs with that of animals in three broad categories that also include dogs: domestic animals, social hunters, and carnivorans. They published their findings in a paper titled In What Sense Are Dogs Special? Canine Cognition in Comparative Context.

What did they find? That some researchers are biased in favor of dogs, and allow that bias to influence their research.

Corresponding author Stephen Lea, MA, PhD, FAcSS, emeritus professor of psychology at the University of Exeter, told NEWStat, “Our conclusion is not so much that researchers overestimate canine intelligence—though we do think a bit of that has gone on—as that they overestimate its exceptionality.”

In other words, dogs aren’t necessarily smarter than other animals, but researchers think they are.

Lea says there’s been a slew of studies on dog cognition in the last 30 years, “But it hasn’t been balanced by [a similar amount of research] in animals [who] are, in one way or another, like dogs. And the limited [research] we do have . . . suggests that there’s no task that a dog can be trained on, or will solve spontaneously, that some other, comparable animal can’t also do.”

But when you do compare dogs with other animals, Lea says you come up with some interesting matchups, such as hyenas (carnivorans); chimpanzees and dolphins (social hunters); pigs, goats, and even pigeons (domesticated).

In fact, they found that, when tested, several species in each of those categories had cognitive abilities at least equal to that of dogs.

For instance, dogs can recognize individual human faces; so can pigeons. Dogs can distinguish between individual human voices; so can the spotted hyena, the dwarf mongoose, and the Asian short-clawed otter. Dolphins, chimps, giant pandas, American badgers, two bear species, and sea otters can all use tools at least as well as dogs. In some cases, their cognitive abilities were greater.

Chimpanzees and dolphins can recognize themselves in a mirror; dogs can’t. Plus, pigs, pigeons, and chimpanzees have the ability to remember the what, where, and when of an event, while dogs cannot.

The paper’s coauthor, Britta Osthaus, PhD, a senior lecturer in the School of Psychology, Politics, and Sociology at Canterbury Christ Church University, told NEWStat that while they did find many objective studies, they also found “quite a few that set out to show how clever dogs are, based on nonscientific assumptions.”

For example, one study assumed that a dog would know that a human holding a pen needed something to write on, and would act accordingly by trotting off to fetch a notepad. “There’s no scientific basis for this assumption,” Osthaus says.

Another study trained dogs to open doors. Researchers then had someone try to open a door with their hands full, and the dog “helped” them open it. Osthaus says the problem in that case was that there was no other highly trained behavior the dog might have shown instead. Like, say, calling the elevator. It was either opening the door, or nothing. “This is no proof that the dog was showing any evidence of social understanding and helping behavior,” Osthaus said. “It’s simple operant conditioning.”

Osthaus emphasizes that there are still plenty of papers on dog cognition that show their limitations. “Not all of them are biased,” she said. “But I think we need to be more impartial.”

(Of course, Osthaus may be biased against dogs—she once gave a talk on canine behavior at the University of Bristol with the tongue-in-cheek title “Dogs Are Stupid.”)

So, why do researchers overestimate the intelligence of dogs? Lea think it’s partly because they don’t take the intelligence of comparable species into consideration, but ultimately it may come down to something much more basic.

“People like dogs,” Lea says. “[And] we always like to think the best of animals whom we like.”

Osthaus suggested that it might be better for dogs if people don’t overestimate their abilities.

Only then, Osthaus says, will we “treat them in an appropriate way, accepting their limitations and adjusting our expectations.”

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