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"Chaser, Unlocking The Genius Of The Dog Who Knows     A Thousand Words"
a New York Times BestSeller and #1 Amazon Bestseller

Praise - Good Dog!

Brian Hare - coauthor of THE GENIUS OF DOGS

"Chaser is the most scientifically  important dog in over a century.  Her fascinating story reveals just how sophisticated a dog's mind can be."

Jennifer Arnold - author of THROUGH A DOG'S EYES

"If a truly great book leaves one better for having read it, then Chaser is quite simply a masterpiece.  Dogs and those of us who love them owe a debt of gratitude to the brilliant, courageous author and his equally heroic subject."

Jeffrey Moussaieff Masson - author of WHEN ELEPHANTS WEEP and DOGS NEVER LIE ABOUT LOVE

"This is an extraordinary book, full of warmth and wisdom, that has the potential to forever change the way we look at dogs.

Steve Duno - author of LAST DOG ON THE HILL and co-author of LEADER OF THE PACK

"The genius of Chaser, and of Professor Pilley’s work, is not only about how they have schooled the world on the hidden intellectual capabilities of the canine, but about how they have revealed to us all, in quantifiable terms, the true depth of the bond between humans and dogs.  The real lesson here is how, given enough time, innovation, and love, there are no limits to what can be accomplished with one’s own dog. A good dog can change your life: a great dog, the world."


"After you read Chaser, you will realize that you may have underestimated the intelligence of your dog.  Marvelous insights into a dog's mind."

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Chaser is available worldwide in Spanish, Italian & French

What's in the book


“The first rule of teaching is that you must believe the student can learn. I believed with every fiber of my being that dogs could learn language.”— John Pilley

The amazing and heartwarming story of a very smart Border Collie who knows over a thousand words—more than any other animal of any species except humans—CHASER will revolutionize our understanding of the genius of dogs.


Retired psychologist John Pilley always knew his family’s dogs were much smarter than most scientists would admit. When his wife Sally gave him a Border Collie puppy shortly before his seventy-sixth birthday, he decided to prove it.

Pilley set his sights on teaching his beloved and brilliant dog a record-busting vocabulary of 1,000 proper nouns, in addition to common nouns like house, ball, and tree. By achieving this feat, Pilley demonstrated the remarkable extent of Chaser’s long-term memory, and he illustrated her understanding of words as more than object names and in more contexts than simply fetching objects. Now Pilley has moved on to further impressive accomplishments, exhibiting Chaser’s ability to understand full sentences and to learn new behaviors by imitating her trainer.

Pilley’s groundbreaking approach has opened the door to a new understanding of animal intelligence, one that requires us to reconsider what actually goes on in a dog’s mind. Chaser’s achievements reveal her use of deductive reasoning and complex problem-solving skills to address novel challenges.


Yet astonishingly, Chaser isn’t unique. Pilley’s training methods can be effectively put to use by any dog lovers looking to unlock their dog’s potential. He reveals the impact of effectively channeling a dog’s natural drives (he relied on encouraging Chaser’s natural herding tendencies—she treated her 1,000 toys like her own personal flock of sheep) and incorporating the work of learning words and sentences into stimulating play.


A devoted teacher who worked with Chaser for hours each day, Pilley’s tenacity as a researcher is as inspiring as Chaser’s accomplishments. He has achieved more during his so-called retirement than many do in their entire career, and his work is making the scientific establishment rethink the limits and nature of animal intelligence. Pilley and Chaser’s story points us toward a new way of relating to our canine companions, one that takes into account our evolving understanding of the way animals and humans learn.


A conversation with Dr. Pilley

Why is this book essential reading for dog lovers? How does it differ from other books about dog training and animal behavior?


Readers will discover that their dog is smarter and more capable of learning than they may imagine. Most dog training books offer rote methods for training rote behaviors such as “sit,” “stay,” and “here,” with food as the dog’s primary or sole reward.

My book shares an open-ended method of training that emphasizes playful interaction with the trainer as the reward. Dogs will never tire of play that releases their instinctive drives, and they will never lose interest in joyful interaction with affectionate trainers.


What was your goal in your research with Chaser?


Most research on canine behavior and intelligence has focused on mapping dogs’ innate abilities. Instead, I asked what language abilities a dog could develop with extensive training – four to five hours a day over the course of several years.

An overriding goal of my research has been to teach Chaser concepts as opposed to behaviors. My first peer-reviewed scientific paper on Chaser, co-authored with my colleague Alliston Reid and published in the journal Behavioural Processes in 2010, reported on how Chaser’s learned the abstract concept that objects can have proper noun names. This enabled her to learn the additional concepts of the common noun categories “toy,” “ball,” and “Frisbee,” acquire an understanding of the independent meaning of nouns and verbs, and learn by exclusion (identify a new object on seeing it and hearing its name for the first time, by picking it out of a group of familiar objects). These are abilities that science once thought unique to human beings and that one-to-three-year-old toddlers display as they first acquire language.

In a second peer-reviewed scientific paper, about to be published in a special issue of the journal Learning and Motivation, I report on Chaser’s learning of other abstract concepts, such as elementary syntax and semantics with three elements of grammar, matching to sample, and imitation learning.


What were a few of your major assumptions?


My fundamental assumption was that learning builds upon learning. That is, there are steps to learning and ABCs that must be mastered in every learning situation. Before Chaser could learn that objects have names, she needed to learn the names of obedience behaviors, such as “sit,” “stay,” “here,” and “down,” so that I could guide and maintain her attention on learning tasks.

Another key assumption was that words had to have significant value for Chaser in order to motivate her to learn and remember them. That led me to incorporate her training into behaviors that she found innately reinforcing, such as chasing and herding and finding and fetching games.


What differentiates your research methods from those of other scientists studying dogs?


Most dog studies test a single hypothesis in a laboratory situation using multiple dogs. The dogs belong to non-scientists who are volunteering their beloved pets to participate in the studies, and the researchers have no interaction with the dogs outside the laboratory.


This means that researchers cannot take full advantage of the unique interspecies social relationship that has evolved between dogs and people. To do that, I believe researchers need to live and interact informally with dogs throughout the day, as I have done with Chaser as a member of our family.


You write that one reason scientists have studied dogs only in laboratory settings is a suspicion of so-called Clever Hans effects. Who was Clever Hans and how did you ensure that your findings with Chaser were not the result of Clever Hans effects?


Clever Hans was a horse in early twentieth-century Germany who could apparently do arithmetic, tapping his hoof to count out numbers. In fact, his owner’s body language was unintentionally cueing him when to start and stop tapping his hoof.

Extensive blind and double-blind tests, including other testers than myself, have ensured that Chaser’s language learning is genuine and is not the result of any physical or other cues from a person.


What are the broader implications of your work?


The most powerful paradigm in animal science has come down to us from Descartes, the seventeenth-century philosopher who decreed, without any experimental evidence, that animals are flesh-and-blood machines that cannot think or feel – and thus obviously cannot play, either. That paradigm has continued to limit what animal science can discover up to the present day.

A paradigm in science holds sway so long as the scientific consensus can ignore or dismiss anomalies that contradict it. With her unprecedented language learning, Chaser extends the evidence from previous language-trained animals such as the chimpanzee Washoe, the dolphins Phoenix and Akeakamai, the African gray parrot Alex, the bonobo Kanzi, and her fellow Border Collie Rico. Together these animals’ abilities stand as anomalies that can no longer be dismissed or ignored. They tell us that it is past time to abandon Descartes’s paradigm of animals as machines and to replace it with a new paradigm of animals as truly our fellow creatures – biologically, emotionally, and cognitively.


Do you think that any of the techniques you’ve used for teaching Chaser could be adapted for teaching children?


The most important take-away from the book is that learning is best acquired by means of play in the context of a positive, mutually respectful relationship. I saw in my college teaching how play frees the mind from tension and opens the door to creative thinking and problem-solving. I have incorporated practically all of Chaser’s training into games that she loves to play because the games give her opportunities to express her strongest instinctive drives.

Her most important instinctive drive, in terms of her ability to learn, is one she shares with all domestic dogs: the drive to bond and interact with a human being. The importance of play goes hand in hand with the importance of an affectionate relationship between teacher and student.

What I am asserting about play and creative learning potential may not yet be a testable scientific hypothesis, but I am sure that eventually it will be. And I believe that testing will confirm and extend the hypothesis that the most profound learning is impossible without play.

The other fundamental principle that applies to teaching any animal or human student is that teaching has to respect the individual’s temperament and personality. One size does not fit all.

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