Some dogs can classify their toys by function

Certain dogs can not only memorize the names of objects like their favorite toys, but they can also extend those labels to entirely new objects with a similar function, regardless of whether or not they are similar in appearance, according to a new paper published in the journal Current Biology. It's a cognitively advanced ability known as "label extension," and for animals to acquire it usually involves years of intensive training in captivity. But the dogs in this new study developed the ability to classify their toys by function with no formal training, merely by playing naturally with their owners.

Co-author Claudia Fugazza of Eötvös Loránd University in Budapest, Hungary, likens this ability to a person calling a hammer and a rock by the same name, or a child understanding that "cup" can describe a mug, a glass, or a tumbler, because they serve the same function. “The rock ...