Dogs Can Learn Words Quickly

It has been known for years that dogs can fetch objects and sit on command. A study suggests that they have the ability to remember words for dozens of objects, even some of them for weeks.

The researchers found that Rico, a border collie, understands more than 200 words and can learn new ones quickly. Rico knows the names of dozens of play toys and can find the one called for by his owner. That is a vocabulary size about the same as apes, dolphins and parrots trained to understand words, the researchers say.

The border collie, a breed known primarily for its herding ability, was able to go to the room with the toys and, seven times out of 10, bring back the one he had not seen before. Rico seemingly understood that, because he knew the names of all the other toys, the new one must be the one with the unfamiliar name.

This kind of rapid word learning is called "fast-mapping", also used by young children to form quick and rough ideas about the meaning of a new word. When it came to matching new words to objects, Rico performed about as well as an average 3-year-old. Julia Fischer, a researcher with the Max Planck Institute for Evolutionary Anthropology in Leipzig and her colleagues do not claim that dogs and toddlers have an equally rich understanding of words.

"Apparently he was able to link the novel word to the novel item based on exclusion learning, either because he knew that the familiar items already had names or because they were not novel," the researchers said in an article in the U.S. journal Science.

A month later, he still remembered the name of the new toy three out of six times, even without seeing it since the first test. That is a rate the scientists said was equivalent to that of a 3-year-old.

While dogs may be smarter than many people thought, Paul Bloom of Yale University, who was not involved in the study, urged caution. "Children can understand words used in a range of contexts. Rico's understanding is manifested in his fetching behavior," Bloom wrote in a commentary, also in Science.

Ms. Fisher says dogs' long history of domestication might have enhanced their vocabulary abilities.

"Certainly it does help that dogs have been bred to attend to humans and that is something that has been selected for in many dogs," she adds. "But I think, nonetheless, in principle we would be able to find this in other animals as well."