The year was 1994. People were fresh-faced and wholesome, The Simpsons was on its fifth season, and the US had just approved the use of genetically modified foods.
Against this backdrop, psychologist Stanley Coren was devising a definitive scale of dog breed intelligence. He was about to change our scientific understanding of dogs forever.
Coren conducted interviews with show judges and investigated the theory that different dog breeds, genetically distinct as they are, naturally possess difference levels of cognitive potential.
He examined many different types of intelligence—adaptive, working, instinctive, spatial, kinaesthetic and interpersonal—before ranking all official dog breeds.
In doing so, Stanley Coren laid the groundwork for modern canine studies. Two decades later, we now know that dogs demonstrate types of intelligence seen in no other animals except humans. Not even our primate ancestors.
How could this be?
The last decade of dog research has revealed a great deal. We have learned that thousands of generations of domestication—starting sometime between 20,000 and 40,000 years ago—have evolved in dogs the capacity to interpret human facial expressions, body language and even social gestures.
This relies on the development of a number of cognitive processes. And so, the unique relationship between humans and dogs has bestowed them with intelligent traits like inferential learning.
This is one example of what sets us—and now dogs—apart from all other life on Earth.
It's a brilliant example of neurobiological symbiotic evolution. Man and dog, helping each other up the evolutionary ladder.
So let's take a look at some of those unusual modes of dog intelligence now.
1. The Border Collie
Chaser is a female Border Collie dubbed "the smartest dog in the world".
She lives with retired psychology professor John Pilley who has taught her to recognise 1,022 words based on her toy collection of 800 stuffed animals, 116 balls and 106 plastic toys.
She also follows directions like "paw the doll", "nose the chicken", "find the circle" and "take it out".
But these aren't just cutesy dog tricks. Chaser is likely the most important dog in modern scientific research.
What Chaser demonstrates goes way beyond operant conditioning: she has developed the capacity to learn in the same way human toddlers learn, through social inference.
If I secretly hide a ball under one of three cups, a young child can infer hints like pointing or gesturing to choose the correct cup. Even bonobos, our closest genetic relatives, can't do that.
But recently, scientists have found some particularly intelligent dog breeds like Border Collies can.
2. The Poodle
Right now there's a Poodle on board the International Space Station.
This news got me WAY too excited until I discovered it's just a stuffed Poodle, belonging to one of the Russian cosmonauts.
It has a job, at least, to act as a zero-G indicator so that when the humans are strapped down, they can watch the pooch float and tell when they've reached the realm of microgravity.
Detours aside, my dog intelligence research led me to Samantha, a three-year-old Poodle who, on a whim of her own, organises her toys in the living room in various sequences. She has phases of lining them up in order of most-to-least favourite, and phases of a most-recently-used (MRU) stack, making her an unofficial canine programmer.
At other times, she lines up her toys so she can lay with her leg contacting all of them. Such a desire to repeatedly line up objects up is a perfectly relatable human trait, based on a love of systematic organisation.
Meanwhile, her mate Louis is a one-year-old Poodle that uses his nose to bump open door handles and escape from doggy day care, while Inigo is another Poodle who opens the kitchen freezer and helps himself to frozen chicken while no-one's looking.
We must congratulate them heartily on their cunning displays of adaptive—aka problem solving—intelligence.
3. The German Shepherd
Aside from working as police and security dogs, German Shepherds have also been employed to detect lung cancer from human breath samples.
Research has seen them successfully identify 71/100 (71%) of lung cancer patients and 372/400 (93%) of healthy patients.
Such ability relies on three things: a powerful sense of smell (they have millions more scent-detecting cells than us), the extra brain capacity dedicated to processing this information, and the language processing ability to comprehend and respond to human instructions.
Of course, it took time to train these dogs through psychological conditioning, and it's unclear if they comprehend the cancerous smells as signifying disease. They are perhaps just following orders; identifying which smells are different from the rest.
For science, having dogs that can smell cancer won't put them on the front line of cancer diagnosis.
But it could help scientists identify the organic compounds associated with the disease, leading to better diagnostic technologies and earlier detection.
4. The Golden Retriever
Golden Retrievers are superb examples of artificial selection, where breeders choose which pooches to mate based on their looks, personality and health status.
The result is evident in the personalities of many Golden Retrievers who are famous for being so perfectly biddable and, well, nice.
But you better give your Golden Retriever a job to do, or he'll improvise one for himself. The brain of a Golden Retriever has more neurons than a cat, hyena, lion, or brown bear, even though the latter has a brain three times larger.
How is this possible?
The behaviourist Celia Haddon says it's down to sociability. Even before domestication began, dogs were descended from wolves who showed complex behaviours and co-operative skills—including appeasement and reconciliation—as a result of their pack-hunting nature.
Cats don't do this, and so have fewer neurons relative to brain size, and rank lower on social intelligence tests. Poor kitty.
The contrast between the evolutionary and domestic history of cats and dogs gives us real insight into our unique symbiotic union with canines.
5. The Doberman Pinscher
Terrifyingly beautiful to look at, the Doberman Pinscher is a stable and friendly dog—that is, until you threaten his family.
As a modern breed he is descended from Germany in the 1880s, when the tax collector Louis Dobermann wanted a dog to protect him and his tax collections from thieves. He mixed together a whole bunch of breeds to settle on the incredible loyalty and protective instincts of the Doberman.
However, recent sloppy breeding practices have regressed this fine tuning and created many Doberman Pinschers with health and temperament problems.
PSA: Never buy a dog from pet stores or anonymous internet retailers, as these are the preferred distribution channels of profit-driven puppy mills. They don't give a crap about producing healthy or good-tempered pets. Not to mention their incredibly inhumane practices.
As the fifth most intelligent dog breed in the world, Doberman Pinschers are known for outsmarting their trainers and getting easily bored. Well-bred and well-trained dogs, on the other hand, can have soft squishy personalities and make super family dogs.
6. The Shetland Sheepdog
It's 4.58pm and my modestly named Shetland Sheepdog, Howard Woofington Moon, has appeared by my side.
His eyes are burning into my head. He whimpers gently, not too forcefully of course, because he knows being polite is the best way to ask for something. He's telling me it's his 1700-hour Dinner Time, thanks to some incredible internal clock in his stomach, or brain, or both.
Howard's not even the smart one. That's his half-brother, Piper, who reacts to my facial expressions, takes turns with us to play hide-and-seek, and understands social gestures like pointing (a skill that's beyond chimpanzees).
Having two Shetland Sheepdogs has taught me that even two dogs of the same breed can have variable personalities and intelligence levels.
For instance, Piper watches animals on TV and barks at them. He howls to summon us when he hears the answerphone kick-in. He licks our wounds obsessively (it's hypothesised that dogs do this to keep their humans fit and healthy, so we can continue to feed them), and frequently checks our faces for social cues.
Howard does little or none of all this, but he does very much like food.
7. The Labrador Retriever
Have you ever wondered why you see more Labrador Retrievers as guide dogs than any other breed?
Aside from the fact that they're ranked the seventh most intelligent dog breed and can pick up new words in few repetitions, it's also thanks to a POMC gene deletion specifically found in Labradors.
The mutation reduces production of the neuropeptides which switch off hunger cues after eating, so they're much more food-centric than other dogs.
The upside is they're easier to train with food rewards. The downside is they're also more likely to become obese.
At two years old, Seesu the Labrador demonstrates fantastic social abilities key to her interaction with humans. She can follow the direction you're pointing, much as humans toddlers can by two years old.
With this gesture in particular, Seesu makes the connection that your perspective of the world is different from hers, that you can see something she can't, and that your gesture has meaning: "hey, look at that thing over there".
Such inferential learning is a huge jump in brain evolution. It's even thought to underpin the development of language and culture in humans.
Unbelievably, scientists have only stumbled on this understanding of dog intelligence in the last decade, which is more of a reflection of much we've ignored studying dog brains until now.
Read more on this evolving subject with The Genius of Dogs: How Dogs Are Smarter Than You Think by Brian Hare.