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www.english0905.com Unit 12

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By the end of this process, Alex had the intelligence of a
five-year-old child and had not reached his full potential.
He had a vocabulary of 150 words. He knew the names of
50 objects and could describe their colours and shapes.
He could answer questions about objects’ properties,
even when he had not seen that particular combination of
properties before. He could ask for things, and would reject
a proffered item and ask again if it was not what he wanted.
He understood the concepts of ‘bigger’, ‘smaller’, ‘same’
and ‘different’. And he could count up to six, including the
number zero. He even knew when and how to apologise if
he annoyed Dr Pepperberg or her colleagues.

6

There are still a few researchers who think Alex’s skills were
the result of rote learning rather than abstract thought. Alex,
though, convinced most in the field that birds as well as
mammals can evolve complex and sophisticated cognition,
and communicate the results to others.
D Early studies had concluded that linguistic ability in apes
Adapted from The Economist was virtually non-existent. But researchers had made
the elementary error of trying to teach their anthropoid
subjects to speak. Chimpanzee vocal cords are simply
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not up to this, and it was not until someone had the idea
A And so it proved. Using a training technique now
of teaching chimps sign language that any progress was
employed on children with learning difficulties,
made.
Dr Pepperberg and her collaborators at the University
of Arizona began teaching Alex how to describe things,
how to make his desires known, and even how to ask E However, not all animals which live in groups can be
questions. classified in this way. Flocks of, say, starlings or herds of
wildebeest do not count as real societies, just protective
groupings. But parrots such as Alex live in societies in the
B And the fact that there were a lot of collaborators, even
wild, in the way that monkeys and apes do, and thus, Dr
strangers, involved in the project was crucial. Researchers
Pepperberg reasoned, Alex might have evolved advanced
in this area live in perpetual fear of the ‘Clever Hans’
cognitive abilities.
effect. This is named after a horse that seemed to be
able to count, but was actually reacting to unconscious
cues from his trainer. Alex would talk to and perform for F The dictionary definition of to parrot is to repeat exactly
anyone, not just Dr Pepperberg. what someone says without understanding it. It is used
about politicians who simply repeat the party line, or
schoolchildren who learn facts by heart. Dr Pepperberg’s
C Dr Pepperberg’s reason for suspecting that they might –
experiments with Alex have helped to demonstrate the
and thus her second reason for picking a parrot – was that
validity of this usage.
in the mid-1970s evolutionary explanations for behaviour
were coming back into vogue. A British researcher called
Nicholas Humphrey had proposed that intelligence G This novel approach came to Dr Pepperberg, a theoretical
evolves in response to the social environment rather than chemist, in 1977. To follow it up, she went to a pet shop
the natural one. The more complex the society an animal and bought an African Grey parrot, which was then just a
lives in, the more intelligence it needs to prosper. year old. Thus began one of the best-known double acts
in the field of animal-behaviour science.

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