Your toddler studies an object, her face focused and intent. "Cup!" she declares. You squeal in delight, then grab your phone to spread the news.
Of course you keep a mental tally as your little one masters new words. But what about your dog's vocabulary? You know he's got the basics: sit, walk, ball; but research shows he may have stored away more words than you think.
According to Dr. Stanley Coren, an expert in canine intelligence, the average dog can understand about 165 words, possibly more with training. Consistency is key, says Coren. If you call his meal "supper" but your spouse calls it "dinner," the label for his nightly kibble might be fuzzy. But if everyone says "dinner," he'll soon perk up anytime you're discussing dinner plans.
Meet the canine super learners
Interest in canine intelligence spiked in 2001, when Rico, a border collie, appeared on a German TV game show and showed he could recognize 200 different words. In later studies at the Max Planck Institute for Evolutionary Anthropology, Rico proved he could use process of elimination to figure out unfamiliar words, and he could remember new words even after a month of not hearing them.
Rico held the record until Chaser, another border collie, displayed knowledge of a whopping 1,022 words. Chaser's owner, John W. Pilley, is a psychologist at Wofford College in Spartanburg, South Carolina. Pilley began training Chaser in 2004, teaching her the names of up to two toys each day. Over a three-year period, Chaser built immense vocabulary skills, while sporting a hefty toy collection. Chaser's feats were published in a study in the Behavioural Processes Journal in February 2011.
On the next page, get a closer look at how dogs learn and the ways they attach meaning to our words.