Many readers will have seen or read of amazing animals who can count, or respond to complex commands. Most of these are the result of simple stage tricks, but researchers at South Carolina's prestigious Wofford College have Chaser the super smart Wonder Dog.
Chaser is a female Border Collie and she has learnt to recognises the names of over a thousand objects; but not only does she recognise them, she can differentiate between the names of the different objects and orders to fetch them.
This research went even further than earlier German research that involved a dog that knew the names of a couple of hundred objects. The Wofford researchers had been left wondering just how far a dog could go and whether it really did understand that the object names were nouns and not simply commands to retrieve the object.
They really wanted to know exactly how large a dog's vocabulary can become if given extensive training and what dogs can actually understand when we use human language to communicate with them.
The researchers, John Pilley and Alliston Reid, demonstrated that in three years Chaser learnt the names of 1,022 objects. There was apparently no upper limit and training only stopped, not because Chaser had reached saturation point, but because they simply ran out of time.
The study demonstrates Chaser's ability to learn the names of proper nouns and her extensive vocabulary was repeatedly tested under carefully controlled conditions. The 1,022 objects were her toys and the researchers admitted that she remembered their names better than they did.
Chaser's ability to remember over a thousand proper nouns, each attached to a unique object, revealed that not only could she discriminate between the different sounds, she could discriminate between them visually. It was also clear that she had an extensive vocabulary and a substantial memory system that was able to link the auditory and visual stimuli.
In their second experiment Pilley and Reid demonstrated that Chaser really understood that these were names of objects and not commands to go and fetch. In order to test this, the researchers randomly combined nouns with commands to see if Chaser would produce the correct behaviour towards the correct object in each trial.
No special training was given and from the outset Chaser responded correctly every time. It was clear that she fully understood that the commands and the names of the objects had completely different meanings, with the names referring to the object in question and not to the action involving the object.
The third experiment demonstrated that Chaser understood the names for categories of objects or common nouns, rather than individual names or proper nouns. She learnt that "toy" referred to all of the 1,022 objects that she was allowed to play with and that some of these toys might be balls or Frisbees.
Additional research is needed to determine whether or not this impressive learning ability is solely confined to Border Collies or whether other breeds of dog can be similarly successful.