What makes the dog-human bond so powerful? In a word, reciprocity.
Japanese researchers found that dogs and humans have a give-and-take relationship so powerful that it’s controlled by the very same hormone—oxytocin—that binds mothers and infants, reduces anxiety and depression, and builds trust and intimacy.
In the age-old war between cats and dogs, canines might just have struck the killer blow. A border collie called Chaser has been taught the names of 1022 items – more than any other animal. She can also categorise them according to function and shape, something children learn to do around the age of 3.
These are powerful arguments to demand new legislation to protect dogs from all harm and exploitation.
To find out whether there was a limit to the number of words a border collie could learn, psychologists Alliston Reid and John Pilley of Wofford College in Spartanburg, South Carolina, started an intensive training program with Chaser.
Over three years, they taught the collie the names of 1022 toys by introducing them to her one by one, getting her to fetch the toy and then repeating the name to reinforce the association.
The team regularly tested Chaser on her entire vocabulary. Groups of 20 toys were chosen at random and put in a separate room from where Chaser had to retrieve them by name. The toys were in another room so the trainer would not unintentionally give Chaser cues about which toy to choose. According to Reid, the dog completed 838 of these tests over 3 years and never got less than 18 out of 20 right.
Chaser was also taught to categorise the named objects, complete tasks such as touching the toy with her nose or paw, and she could infer the name of a new object from a set of familiar objects.
Ádám Miklósi, founder of the Family Dog Project at Eötvös Loránd University in Budapest, Hungary says that other dogs perform similar tasks, he says, but they usually make more mistakes. He thinks Chaser’s intensive training explains the difference.
Others animals have demonstrated impressive feats of learning in which they also vocalise the words they learn, such asAlex, the parrot who could make sentences out of about 100 words. And then, there is Koko, the Gorilla, whose ability to love is as great as ours.