by Jane McGrath
"I'll teach my dog 100 words," says the boy in the children's story of the same name. But can he really? Dog owners love to gush about canine intelligence. So it would come as no surprise to them that research supports their beliefs that dogs have a profound mental capacity. But how much of our language do dogs really understand? It turns out that the language comprehension of some dogs rivals that of apes and parrots, not to mention the average 3-year-old.
Sure, most dogs understand the basics --"fetch," "sit" and "stay." But if you have the motivation and patience, you will probably be able to teach your dog even more than 100 words. Stanley Coren, a psychologist who has performed a significant amount of research on the subject of dog intelligence, suggests that average trained dogs know about 160 words [source: Coren]. Some dogs even show a vocabulary as vast as a human toddler's.
Since at least the 1970s, when researchers successfully trained chimpanzees to use and read words in sign language, we have known that language, in a loose sense of the term, is not unique to humans. Animals have the brain power to understand human language and use their own languages in surprisingly profound ways. We all know parrots can be trained to speak human words. And dogs will react to the word "walk" with a knowing, tail-wagging enthusiasm.
How deep is the dog's bank of human words? On the next page, we'll take a look at one border collie's remarkable talent at retrieving objects of different names.
What Rico tells us about a dog's understanding of language
After being featured on a television show for his ability to understand 200 words, a border collie named Rico intrigued some researchers at the Max Planck institute. These researchers asked if they could bring Rico in to perform some experiments to find out just how far they could stretch the dog's language ability. The answer: surprisingly far.
At first, the researchers wanted to verify in a controlled setting whether Rico really knew 200 words. To do this, they collected 10 items with which Rico was familiar. At the verbal command of his owner, they had him fetch a specific item from a separate room. Rico performed very well at this task, but the researchers wanted to challenge him further. Next, they chose a new item -- one that Rico had never seen in his life -- and placed it in the room among the familiar items. The owner requested that new item by name and, lo and behold, Rico brought back the new item.
Researchers performed this test several times, each time with another new item, and found that Rico brought back the correct item an impressive 70 percent of the time. This demonstrated not only that the dog had a large vocabulary, but also that he knew how to use process of elimination.
Impressed as they were, researchers pushed Rico further with an even more difficult task. They wanted to find out whether Rico could remember the items that he learned in the experiment after only one exposure, a process called fast-mapping, which children can do. One month after Rico proved his language abilities in the lab, researchers brought him back in. This time, they put one of the new items that Rico correctly fetched a month earlier in a room with four familiar and four unfamiliar items. When his owner requested it, Rico was able to correctly fetch the item he had learned a month previous as much as 50 percent of the time. Though that might not seem remarkable, it was to the researchers, because this success rate compares with that of 3-year-old children.
However, whether a dog's "understanding" of a word compares to a child's is another matter. In order to address that question, we'll need to get a better grasp on how language works, and we'll do that on the next page. (more)
