Rico, the nearly nine-year-old Border collie, can learn the names of unfamiliar toys after just one exposure to the new word-toy combination. The scientists equate the dog’s apparent learning to a process seen in human language acquisition called “fast mapping.” The fast mapping abilities of children allow them to form quick and rough hypotheses about the meaning of a new word after a single exposure.
The German team first verified Rico’s 200-word “vocabulary.” In a series of controlled experiments, Rico correctly retrieved, by name, a total of 37 out of 40 items randomly chosen from his toy collection. The authors write that Rico’s “vocabulary size” is comparable to that of language-trained apes, dolphins, sea lions and parrots.
Next, the researchers tested Rico’s ability to learn new words through fast mapping. Fischer’s team placed a new toy among seven familiar toys. In a separate room, the owner asked Rico to fetch the new item, using a name the Border collie had never heard before.
Rico correctly retrieved a new item in seven of ten sessions. He apparently appreciates, as young children do, that new words tend to refer to objects that do not already have names. After a month without access to these target toys, Rico retrieved them, upon request, from groups of four familiar and four completely novel toys in three out of six sessions. His retrieval rate is comparable to the performance of three-year-old toddlers, according to the authors.