(Originally written for DogWatch, a newsletter for the general public from the Cornell University College of Veterinary Medicine)

A coworker brought in an article that ranked dog breeds based on an “IQ test” which she says proves her dog is smarter than mine. My Dufus may not be not the brightest candle in the box, but can any test really prove say that one breed is smarter than another?

Intelligence tests for dogs suffer from all the limitations of intelligence tests for humans, plus a few more. When it comes to testing members of a different species, the most any test can do is test what its designers think an intelligent dog should know. Right away that gets us into trouble because, although fewer and fewer people cling to the idea that dogs don’t think, a lot of people still believe that dogs think—or should think—the same way we do. However, dogs perceive their worlds quite differently from humans and use their brains differently to process that data. For example, Dufus’s owner most likely recognizes him based on his distinctive physical features: his pointed or squashed nose, long or short coat, brown or white spots, lanky or stocky body type. In keeping with this orientation, human brains allot a fair amount of grey matter to the processing of this detailed visual information. On the other hand, dogs perceive their owners as odor-laden, greyish-yellow-blue blobs of more or less detail depending on their distance from that person. Consequently, much more of their brains is devoted to processing motion and scent data than detail.

Further complicating matters, if we ask a hundred people what they think a dog with average intelligence should know, we could conceivably get a hundred different answers. A person who views dogs strictly as companion animals might consider the average time it takes to house train pups of a particular breed a major sign of intelligence. Another person who wants a dog to perform a particular function, such as bird-hunting, might see a pup’s willingness to retrieve as a far more reliable sign of brain power.

Any valid canine IQ test also must take into account any inherent breed differences. Sight hounds, such as greyhounds, Afghans, and borzois, could score higher on tests involving visual cues whereas scent hounds such as bassets and bloodhounds could make some sight hounds look pretty dense if scent-based tests were the standard. Breeds, such as beagles or coonhounds, bred to hunt a specific type of prey demonstrate a different kind of thought process than those bred to herd sheep or cattle. A good hunting beagle will focus all of its attention on first detecting, then following a scent to its source, and ignore any distractions except its owner’s commands. While this particular mind set allows the beagle to hunt far more efficiently than any person, such a thought process wouldn’t benefit a working border collie who must be able to juggle multiple concepts simultaneously. In addition to moving the flock toward a specific goal, a good herding dog must monitor its charges for any signs of dawdling or escape, plus observe the area surrounding the flock for potential dangers. At the same time, the dog must remain alert to any signals from the herdsman, too.

However, while good working dogs often perform feats that their owners consider nothing less than brilliant, those humans who lack the lifestyle and personality to provide a proper outlet for that amount and quality of canine mind-power don’t fare nearly so well. Rather than viewing their pets as incredibly clever, they see their hunting dogs as single-minded and thick-headed and their herders as flighty and unmanageable.

How in the world can any test take all these differences into account? And what about all those wonderful mongrels out there?

While some people may strive to reduce canine intelligence to a one-size-fits-all standard for convenience sake, wise pet owners maintain their own criteria. Like Dufus, many dogs might not win any canine rocket scientist awards, but the proof is in the pudding—or rather in the living. So what if the dog loses his favorite ball or occasionally sneaks on the couch? When it comes to fitting into our complex lives and making us happy, most of our pets are downright brilliant.