There’s no doubt that dogs have a lot of human-like qualities, and some dog owners are impressed by how many "people words" their dogs are able to learn. But a new study suggests that while dogs can certainly learn human words, the way in which they process language is quite different, and this difference tells us something about how language evolved in the brain.

A Border Collie's Dictionary of Toys

Researchers taught a border collie to associate a word with a particular toy – for example, an L-shaped toy. Challenging him with several choices after the initial training period, they found that he generalized the name of an object to others of a similar size, rather than shape. By contrast, when human kids learn language, they generalize based on shape. For example, kids naturally associate a round object of any size with the word "ball." But the dog in this study, Gable, associated toys of the same size with a particular word, even if they were very different shapes.

Kids naturally associate a round object of any size with the word 'ball.' But for dogs, it's about size.

The team also found that after a bit more training, Gable was able to generalize a particular word to other objects of similar texture, but again, he did not generalize to shape. Earlier evidence had also shown that children also tend to generalize to shape instead of texture. But shape never did seem to come into play for Gable.

What Dogs Can Tell Us About People

The authors conclude that the mammalian brain is not "primed" for language comprehension in a specific way – that is, mammals clearly don’t all generalize in the same way across the board. Rather, it seems that the sensory systems evolved in different manners, and this evolution is specific to a particular type of animal.

The study's findings may be helpful to people who train service animals to develop a large vocabulary of human words.

"It is only by comparing other species with humans that we can find out more about the neural and genetic foundations of word reference in language," said lead author Emile van der Zee. The researchers made sure that smell did not come into play while Gable was making his decisions, but acknowledge that smell should be taken into account in future studies.

The study's findings may be helpful to people who train service animals to develop a large vocabulary of human words. And for the rest of us, it provides a good reason not to be too hard on your pup when he brings his stuffed squirrel instead of the ball you asked for.

The study was carried out by a team at the University of Lincoln, and published in the open access journal, PLOS ONE.