Border collie knows 1,000 words
GREENVILLE, S.C. — The experiment began with a racquetball that has now been replaced many times.
“Chaser! This is Blue,” said John Pilley, a retired Wofford College psychology professor.
“Blue,” Pilley repeated, and rolled the ball to his 2-month-old border collie.
He said the name again as Chaser took the ball in her mouth and held it just out of reach in a coy game of keepaway. Tail wagging, paws clattering, she chased Blue across the room in what became the first steps in her training to learn the human language.
Blue led to Bamboozle, a stuffed orange horse; Choo Choo, a squeaky rubber train, Cinderella, Dora, Drumstick, Ears and Elmo. The house filled up with toys — 800 animals, 116 balls and 26 Frisbees — kept in huge plastic bins on the back porch. Each had a different name written in marker; Pilley could no longer remember them all.
Chaser is now world famous as the dog who knows more than 1,000 words, the largest known vocabulary of any animal except humans. Besides proper nouns, she knows verbs, adverbs and prepositions. She’s learned that common nouns can identify different things. Ball could mean any round or bouncy object, Frisbee any spinning disk or ring. And she can make inferences. If asked to fetch a new toy with a word she’s never heard, she’ll pick the toy out from a pile of familiar ones.
As her language learning grew, so did the experiment. Pilley has recently started to teach Chaser commands with three elements of grammar, going from the basic “take ball” to “take ball to Frisbee.” This is what excites Pilley most as a scientist — that Chaser understands the concept that words play off of one another and that each word in a sentence can have a different meaning.
“We want to stretch it out so we have four, five elements of grammar. They’ve done that with dolphins and chimps, but no one’s done it with dogs,” he said.
There seems to be no end to Chaser’s abilities and her fame. Since Pilley’s findings were first published in 2010, scientists have begun to follow his work as he explores the extent of what dogs are capable of.
Long before Pilley got Chaser, he was intrigued by border collies.
As a breed, they seemed to have the instinctive ability to follow complex commands while herding livestock but also move them across great distances without supervision.
“You’re not breeding them for their looks. You’re breeding them for what’s between their ears,” said Wayne West, who’s bred border collies since the 1960s.
Border collies are herders, now, suggested that a language skill previously thought to be associated only with human children could also be present in another species.
Pilley was eight years into his retirement, but the article’s timing with the arrival of Chaser turned him into a scientist again. He decided to set a goal; he would teach Chaser a thousand words and maybe write a paper himself.
He worked with Chaser for at least five hours a day over three years, slowly building her vocabulary. Pilley tapped into Chaser’s border collie instinct to herd.
Each individually named toy was introduced as if it was part of a flock. “Come by Frisbee,” Pilley might say, using the commands farmers would give collies on a farm.
Fetching and finding objects all over the house made learning memorable for Chaser, but it took repetition. Each toy’s name was said as many as 40 times during an exercise; each exercise was rehearsed 20 times over a day.
Chaser was then re-tested once a month to see what she could remember.
Her success rate never changed; she was right more than 90 percent of the time.
Pilley’s research was published Dec. 8, 2010, and within a week, the news had spread to 46 countries.
Britain’s Daily Mail headlined Chaser as the world’s brainiest dog. On “The Today Show,” she was the canine Einstein.
Animal intelligence experts paid attention, too. Brian Hare, an evolutionary anthropologist at Duke University and author of “The Genius of Dogs,” called Chaser the most scientifically important dog in more than a century.
“There are lots of animals that have been trained to understand hundreds of words ... but what’s interesting is how she learned them and the fact that she learned them through inferential reasoning,” Hare said.