Thinking Bird, or Just Another Birdbrain?
Join a Discussion on Measuring Intelligence
By DINITIA SMITH
TUCSON, Ariz. -- "Calm
down," Alex, an African
Gray parrot, told Dr. Irene Pepperberg, the
scientist at the University of Arizona who owns him.
"Don't tell me to calm down," Dr. Pepperberg snapped.
Sometimes Dr. Pepperberg and Alex squabble like an
old married couple. He even says, "I love you."
For the last 22 years, Dr.
Pepperberg has been teaching
Alex, who is 23, to do complex tasks of the sort that
only a few nonhuman species -- chimpanzees, for
instance -- have been able to perform. But unlike those
other creatures, Alex can talk, or at least, he can
vocalize. And, Dr. Pepperberg says, Alex doesn't just
imitate human speech, as other parrots do -- Alex can
think. His actions are not just an instinctive response,
she says, but rather a result of reasoning and choice.
Assertions like Dr.
Pepperberg's are at the
center of a highly
emotional debate about
whether thought is
solely the domain of
humans, or whether it
can exist in other
many people are
intrigued by the idea
that animals may be
capable of some form
of abstract reasoning and communication, scientists
often ascribe what looks like clever behavior to
mimicry or rote learning or even, in some cases,
unconscious cues by a trainer.
So, just how smart is Alex?
The question of animal intelligence
goes back at least
to Descartes and his famous aphorism, "I think,
therefore I am." Animals cannot think, said Descartes,
and therefore are inferior to humans. And for many
theologians and philosophers, the ability to think gives
man a unique closeness to God.
Parrots, of course, are famous
mimics, and some
parrots have bigger vocabularies than Alex. But no
parrot, says Dr. Pepperberg, has been able to perform
tasks as complex as Alex can. And she believes that
when Alex vocalizes, he is expressing the results of his
thoughts, not mere mimicry. For instance, when she
asks Alex what color corn is, he answers yellow, even
though there is no corn around. This means, she says, he
has an abstract concept of what the words "color,"
"corn" and "yellow" mean. He has not simply
memorized them, but can apply them to different
Chimpanzees and dolphins
have been able to perform
equally complex tasks, though the tasks differ from
those given to Alex because of the differences between
species. But chimps and dolphins, obviously, cannot
vocalize in the way Alex does.
Few scientists would dispute
that Alex is doing
something unusual in the history of animal studies. At
least, his behavior is more advanced than that of most
other parrots who have been the subject of scientific
experiments. But scientists differ on the implications of
Until now, Dr. Pepperberg
has published her work in
scientific journals, but in January Harvard University
Press will publish "The Alex Studies," a book
summarizing her experiments with Alex.
Dr. Pepperberg bought Alex
at a garden-variety pet
store in Chicago when he was about a year old with the
idea of studying him. As far as she knew, he had no
particular pedigree, and she is not even sure whether he
is particularly smart in relation to other parrots. Now
she is trying to replicate his training with another Gray
Dr. Pepperberg, listing Alex's
he could identify 50 different objects and recognize
quantities up to 6; that he could distinguish 7 colors and
5 shapes, and understand "bigger," "smaller," "same"
and "different," and that he was learning the concepts of
"over" and "under." Hold a tray of different shapes and
colored objects in front of him, as Dr. Pepperberg was
doing the other day as a reporter watched, and he can
distinguish an object by its color, shape and the
material it is made of. (Dr. Pepperberg said she
frequently changed objects to make sure Alex wasn't
just memorizing things and that she structured
experiments to avoid involuntary cues from his
But today Alex was being recalcitrant.
Dr. Pepperberg had been away
for three weeks at
M.I.T., where she is a visiting professor this year.
When she leaves him, she says, Alex chews at his tail
and wing feathers, giving him a rather threadbare
appearance, and when she returns he is very
demanding, turning his back and saying, "Come here!"
"What matter is orange and
three-cornered?" she asked
Alex, holding the tray of objects in front of him. First,
Alex had to identify which object was orange and
three-cornered, and then tell Dr. Pepperberg what it
was made of. She allowed Alex to pick up the objects
on the tray with his beak and to "examine" each one.
But after he finished, instead
of giving an answer, Alex
demanded a nut. "Want a nut," he said clearly, sounding
almost human. (He also responds to other people's
commands, Dr. Pepperberg's graduate students for
"I know, I'll give you a
nut," Dr. Pepperberg said,
"Wanna go back," said Alex,
meaning go back into his
Dr. Pepperberg continued
trying to get Alex to perform,
but he resisted and she began to lose patience.
"C'mon, Alex," she said.
"I'm sorry," he said.
Usually, said Dr.
Pepperberg, that means he is about to give in.
"What matter is orange and
three-cornered, Alex?" she
"Wool!" said Alex, getting it right.
Dr. Pepperberg refuses to
call Alex's vocalizations
"language." "I avoid the language issue," she said. "I'm
not making claims. His behavior gets more and more
advanced, but I don't believe years from now you could
interview him." She continued: "What little syntax he
has is very simplistic. Language is what you and I are
doing, an incredibly complex form of communication."
Still, many scientists and
others remain unconvinced.
What about unconscious cues from the trainer? Perhaps
the most famous instance of that involves Clever Hans,
a horse at the turn of the century who could supposedly
count, tell time and make change by tapping his hoof on
It was learned that Hans's
trainer was tipping him off to
the right answer by tensing his body and moving his
head as Hans "counted."
More recently, Dr. Herbert
Terrace, a Columbia
University psychology professor, famously repudiated
his own studies in the 1970's with a chimpanzee he
called Nim Chimpsky, after the M.I.T. linguist Noam
Chomsky. Dr. Terrace taught Nim to use signs that
looked as if they were combined grammatically into
sentences. But it turned out they were clever imitations
of his teacher.
Asked about Alex, Dr. Terrace
said he thought that
what Alex was doing was "a rote response." He calls it
"a complex discriminative performance."
But is Alex thinking? "I
would say minimally," Dr.
Terrace responded. "In every situation, there is an
external stimulus that guides his response." Thought, he
said, involves the ability to process information that is
not right in front of you.
"It shows Alex is a smart
bird," he said. But if you take
away Alex's ability to vocalize in a way that seems
human, he went on, it would not seem as impressive:
"The words are responses, are not language."
On the other side of the
animal-intelligence debate is
Dr. Donald R. Griffin, author of "Animal Thinking,"
who coined the phrase "cognitive ethology," the study
of animal cognition. He believes that animals are
capable of complex thought and behavior that is not just
The discovery that "a bird
can express his conscious
thoughts and feelings," said Dr. Griffin, "is a great
We used to think that was
impossible." To Dr. Griffin,
Alex's achievements are just one more proof of his
Dr. Griffin's views of animal
intelligence have been
hotly contested. "The intensity of the aversion is
incredible," he said. "It's a very touchy subject.
Scientists don't like to
be told that a valid reason for
what an animal does is the possibility that it does it
with any consciousness."
Dr. Steven Pinker, an M.I.T.
scientist and author of
"How the Mind Works," said that at the heart of the
debate is the question of human primacy. "In earlier
times the issue was of whether we are mere animals,
and to separate and exalt human worth. Ironically, there
has been the same kind of moralistic return from animal
fans who say we shouldn't mistreat them because they
think and feel the way we do."
Dr. Pinker believes that
human beings alone are
genetically programmed to learn language
spontaneously and easily. "I think it is rather an ironic
definition of animals to tend to enoble them by training
them to mimic humans."
Until recently, birds had
been thought of as on the low
end of the intelligence scale -- hence the term
"birdbrain." The point, Dr. Pepperberg said, is that
Alex "is a nonmammal, nonprimate, with a brain the
size of a walnut." And Alex's accomplishments. she
added, show that "animal intelligence is more
widespread than we thought."
Dr. Pepperberg attributes
what she calls Alex's ability
to reason and process complex information to her
training methods. Most training of birds has followed
the conditioning theories of B. F. Skinner, the
behaviorist. A bird is taught to say or do a specific
thing by a human instructor and is rewarded with food.
Dr. Pepperberg initially
uses the object itself as a
reward so that the bird associates the word with the
object. She uses two human trainers instead of one to
demonstrate the interaction she is trying to teach Alex.
For instance, Dr. Pepperberg
stands in front of Alex
with a graduate student and orders the student to select
a three-sided orange object and to say what the object
is made of -- wool, perhaps.
She believes that by watching
the interaction, Alex
connects the graduate student's response to the
command. "Orange" she believes, comes to mean to
Alex the color of an object rather than the immediate
reward of a grape.
Dr. Pepperberg says her experiments
beyond determining whether -- or how well -- animals
She says her methods have
been successfully used to
train autistic children and children with learning
disabilities. Alex's achievements, she said, also
underscore the need for stricter conservation of parrots,
which are an endangered species.
Dr. Pepperberg, who is 50,
was born in New York
City, an only child who kept parakeets as pets and
taught them to speak.
She was studying for her
Ph.D. in chemistry at Harvard,
she said, when she saw a "Nova" series on PBS about
chimps' using sign language, dolphin research and why
birds sing. She wanted to change fields, but her
advisers discouraged her, she said, so she continued
her chemistry studies, continuing nonetheless to read all
she could on animal behavior.
She married and divorced. She has no children.
When she applied for her
first grant to study bird
behavior from the National Institutes of Health, she
said, "there were reviews asking me what I was
"People are not at all surprised
a chimpanzee can do
this," she went on."You can't imagine -- people said
birds were stupid."
Dr. Pepperberg expects Alex
to live at least 20 more
Meanwhile, she has added
two new birds to the lab.
Besides Griffin, now 4 years old, there is Kyaaro, who
Dr. Pepperberg believes exhibits symptoms of attention
"Alex doesn't like either
of them," she said. "Kyaaro is
weird. Griffin is a threat." Right now she is trying to
train Griffin to do some of the things Alex can do.
Griffin, who learned the
word "wool" only recently,
has been clinging to it the way a child clings to a
new-found possession. One day recently Dr.
Pepperberg held up a purple plastic letter S and asked,
"What sound is purple?" Griffin stared at the letter.
But from the other side of
the laboratory Alex made the
sound for him, "Sss."
"Buttinsky," Dr. Pepperberg
said to Alex, and she
turned back to Griffin.
"What sound?" she asked Griffin
again, holding up the
"Wool," said Griffin.
Griffin has a long way to