Alex, the world’s most famous African Grey parrot, died September 6, 2007, and the world is a sadder place for it.

You may be wondering why a column about dog behavior would begin with a memorial to a parrot, but there is an important connection between Alex’s behavior and that of your dog. It was Alex, and his human, Irene Pepperberg, who stretched our understanding of what goes on in the minds of nonhuman animals, including the furry best friend lying at your feet.

When, in 1977, Pepperberg began teaching Alex to use words to communicate, the consensus was that animals could be taught to associate sounds with objects (“Go get your ball,”) but not concepts. Concepts are abstractions that live only inside your brain. For example, try picking up a “bigger,” or giving someone a “different” as a birthday present.

The argument used to be that nonhuman animals could only respond to something directly in front of them, and weren’t capable of the kind of cognitive gymnastics that abstractions require. However, Pepperberg’s research taught us that not only could Alex use words to label an object’s shape, form and color (“Alex, pick up the blue triangle out of all the other objects on the tray.”), he had little trouble grasping concepts like “different” and “bigger” (“Alex, what color is the object that is shaped differently from all the rest?”).

Alex’s thought processes, and the way he communicated them, went far beyond answering questions put to him during his training sessions. One day, while looking in the mirror, Alex said, “What color?” Mind you, Alex had been trained to answer questions, not ask them. When the surprised trainers answered, “grey,” Alex was then able to identify other grey objects.

That wasn’t the only time Alex surprised his handlers. I am still amused by a video I saw of Alex working with an impatient trainer. After several interactions, clearly frustrating for person and parrot alike, Alex belted out, in a startlingly clear Bronx accent, “Go away!” But the bird’s most compelling vocalization took place when Pepperberg had to leave him alone, for the first time, at a veterinary clinic. As she walked away, Alex said in a soft and quiet voice, “I’m sorry. I love you. I’m sorry.” (This knowledge has made leaving my dogs at a vet clinic a hundred times harder for me, and I pass it along to you with my own soft and quiet, “I’m sorry.” Ignorance indeed can be bliss.)

When Pepperberg first began working with Alex, there were suggestions that certain other animals could understand simple concepts, but it’s only been during the last 20 years that this issue has gotten the attention it deserves. We’ve found that many animals—including rats, pigeons and a surprising star in cognitive research, the octopus (honest)—can functionally use concepts like “different” and “bigger.”

But what about our dogs? If an octopus can understand the concept “different,” surely our dogs can too. Or can they? Until very recently, research on our best friends has lagged behind that on primates and laboratory rats; apparently, “familiarity breeds contempt” in science as well as in the rest of life. But dogs are finally becoming hot topics in cognitive research—check out, for example, recent issues of the Journal of Comparative Psychology.

Here’s a little about what we’ve learned so far. Research confirms that dogs can also functionally use concepts like “larger” and “different.”* What’s more, in certain contexts, they can also be taught a more complicated procedure called “delayed non-matching to sample.” Here’s how the experiment works: The dog is presented with an object that has a piece of food underneath. He’s allowed to move the object and get the food. Then, after a delay of a varying amount of time, say, 10 seconds, the dog is presented with two objects. One item is the same as before, the other is different. The “right” choice is the different object.

When researchers first conducted the study, the dogs failed miserably. After hundreds of trials, the dogs were still unable to  identify the different object. In comparison, rhesus monkeys figured it out pretty quickly. But when the researchers changed the procedure and asked the dogs to choose an object in a different location, our best friends turned into academic stars, getting the answer right 90 percent of the time—even after waiting 20 seconds between presentations.