Are human speech-like vocalizations made by some mammals
equivalent to conversation--or just a rough estimation of it?
By Tina Adler
Maya, a noisy, seven-year-old pooch, looks straight at me.
And with just a little prompting from her owner says, "I love you." Actually,
she says "Ahh rooo uuu!"
Maya is working hard to produce what sounds like real speech. "She makes these
sounds that really, really sound like words to everyone who hears her, but I
think you have to believe," says her owner, Judy Brookes.
You've probably seen this sort of scene on YouTube and David Letterman. These
dog owners may be onto something: Psychologist and dog expert
Stanley Coren of the University of
British Columbia tells the story of a colleague who always greeted her dog,
Brandy, with a cheerful, two-syllable "Hel-lo!" It wasn't long until Brandy
returned the greeting, which sounded very much like her owner's salutation, says
Coren, author of
How to Speak Dog: Mastering the Art of Dog–Human Communication.
But do dogs really talk? Back in 1912 Harry Miles Johnson of Johns Hopkins
University said, emphatically, "no." In a paper in Science, he generally agreed
with the findings of Oskar Pfungst of the Institute of Psychology at the
University of Berlin who studied a dog famous for its large vocabulary. The
dog's speech is "the production of vocal sounds which produce illusion in the
hearer," Johnson wrote.
He went on to warn that we should not be surprised if "scientists of a certain
class…proclaim that they have completely demonstrated the presence in lower
animals of 'intelligent imitation'."
Nothing in the last century has really changed that scientific opinion. (No one
has ever questioned whether dogs communicate with each other, but calling it
"talking" is something else.) So what are Maya and her cousins doing? It's more
appropriate to call it imitating than talking, says Gary Lucas, a visiting
scholar in psychology at Indiana University Bloomington. Dogs vocalize with each
other to convey emotions—and they express their emotions by varying their tones,
he says. So it pays for dogs to be sensitive to different tones. Dogs are able
to imitate humans as well as they do because they pick up on the differences in
our tonal patterns.
Lucas likens this behavior to that of bonobos, primates that can imitate some
tonal patterns, including vowel sounds, pitch changes, and rhythms, studies
show. "The vocal skills of some of the dogs and cats on YouTube suggest that
they might also have some selective tonal imitation skills," he says.
What's happening between dog and owner-turned-voice-coach is fairly
straightforward, Coren says: Owner hears the dog making a sound that resembles a
phrase, says the phrase back to the dog, who then repeats the sound and is
rewarded with a treat. Eventually the dog learns a modified version of her
original sound. As Lucas puts it, "dogs have limited vocal imitation skills, so
these sounds usually need to be shaped by selective attention and social
reward."
In the Letterman video "a pug says, 'I love you' and it's very cute, but the pug
has no idea what it means," Coren says. "If dogs could talk, they would tell
you, 'I'm just in it for the cookies.'"
Scientists have made some progress in their study of this important subject:
They've learned why dogs, and other animals, have rather poor pronunciation
and, for example, completely botch consonants. They "don't use their tongues and
lips very well, and that makes it difficult for them to match many of the sounds
that their human partners make," Lucas says. "Try saying 'puppy' without using
your lips and tongue."
Despite what they may lack in the elocution department, dogs do communicate
their feelings to humans as well as read our cues, thanks to domestication,
Julia Riedel and colleagues of the Max Planck Institute (M.P.I.) for
Evolutionary Anthropology reported in March 2008 in Animal Behavior. Dogs follow
people's pointing, body posture, the direction of their gaze, and touches for
cues to find hidden food, notes Mariana Bentosela and colleagues at the
University of Buenos Aires in the July 2008 Behavioural Processes. They also
gaze at their trainer when they need more information to find their reward.
Some dogs learn to understand an impressive number of words, as well. A gifted
border collie, Rico, mastered the names of more than 200 objects using a
technique called fast-tracking that small children also employ, Juliane
Kaminski, also of M.P.I. Evolutionary Anthropology and colleagues reported in
2004 in
Science. The researchers introduced a novel item into Rico's mix of toys
then asked him to retrieve it. He did so by associating the unfamiliar name with
the unfamiliar object. He even remembered the name of the toy a month later.
"That's the kind of fast-tracking or exclusionary learning, which we used to
think only human beings and the talking apes—the ones taught language—could
use," Coren says. "For the psychologists it was, 'Wow, how did he learn that
word?!'"
