CAMBRIDGE IELTS 1
PRACTICE TEST 2
READING
READING PASSAGE 1
You should spend about 20 minutes
on Questions 1-12 which are based on Reading Passage 1
below
Right and
left-handedness in humans
Why do humans,
virtually alone among all animal species, display a distinct left or
right-handedness? Not even our closest relatives among the apes possess such decided
lateral asymmetry, as psychologists call it. Yet about 90 per cent of every
human population that has ever lived appears to have been right-handed.
Professor Bryan Turner at Deakin University has studied the research literature
on left-handedness and found that handedness goes with sidedness. So nine out
of ten people are right-handed and eight are right-footed. He noted that this
distinctive asymmetry in the human population is itself systematic. “Humans think
in categories: black and white, up and down, left and right. It’s a system of
signs that enables us to categorise phenomena that are essentially
ambiguous.’
Research has
shown that there is a genetic or inherited element to handedness. But while
left-handedness tends to run in families, neither left nor right handers will
automatically produce off-spring with the same handedness; in fact about 6
per cent of children with two right-handed parents will be left-handed.
However, among two left handed parents, perhaps 40 per cent of the children
will also be left-handed. With one right and one left-handed parent, 15 to 20
per cent of the offspring will be left-handed. Even among identical twins who
have exactly the same genes, one in six pairs will differ in their
handedness.
What then makes
people left-handed if it is not simply genetic? Other factors must be at work
and researchers have turned to the brain for clues. In the 1860s the French surgeon
and anthropologist, Dr Paul Broca, made the remarkable finding that patients who
had lost their powers of speech as a result of a stroke (a blood clot in the
brain) had paralysis of the right half of their body. He noted that since the
left hemisphere of the brain controls the right half of the body, and vice
versa, the brain damage must have been in the brain’s left hemisphere.
Psychologists now believe that among right-handed people, probably 95 per
cent have their language centre in the left hemisphere, while 5 per cent have
right-sided language. Left-handers, however, do not show the reverse pattern
but instead a majority also have their language in the left hemisphere. Some
30 per cent have right hemisphere language.
Dr Brinkman,
a brain researcher at the Australian National University in Canberra, has
suggested that evolution of speech went with right-handed preference. According
to Brinkman, as the brain evolved, one side became specialised for fine
control of movement (necessary for producing speech) and along with this
evolution came right-hand preference. According to Brinkman, most left-handers
have left hemisphere dominance but also some capacity in the right hemisphere.
She has observed that if a left-handed person is brain-damaged in the left hemisphere,
the recovery of speech is quite often better and this is explained by the
fact that left-handers have a more bilateral speech function.
In her
studies of macaque monkeys, Brinkman has noticed that primates (monkeys) seem
to learn a hand preference from their mother in the first year of life but this
could be one hand or the other. In humans, however, the specialisation in (unction
of the two hemispheres results in anatomical differences: areas that are
involved with the production of speech are usually larger on the left side
than on the right. Since monkeys have not acquired the art of speech, one
would not expect to see such a variation but Brinkman claims to have
discovered a trend in monkeys towards the asymmetry that is evident in the
human brain.
Two American
researchers, Geschwind and Galaburda, studied the brains of human embryos and
discovered that the left-right asymmetry exists before birth. But as the brain
develops, a number of things can affect it. Every brain is initially female
in its organisation and it only becomes a male brain when the male foetus begins
to secrete hormones. Geschwind and Galaburda knew that different parts of the
brain mature at different rates; the right hemisphere develops first, then
the left. Moreover, a girl’s brain develops somewhat faster than that of a
boy. So, if something happens to the brain’s development during pregnancy, it
is more likely to be affected in a male and the hemisphere more likely to be involved
is the left. The brain may become less lateralised and this in turn could
result in left-handedness and the development of certain superior skills that
have their origins in the left hemisphere such as logic, rationality and
abstraction. It should be no surprise then that among mathematicians and
architects, left handers tend to be more common and there are more
left-handed males than females.
The results
of this research may be some consolation to left-handers who have for
centuries lived in a world designed to suit right-handed people. However,
what is alarming, according to Mr. Charles Moore, a writer and journalist, is
the way the word “right” reinforces its own virtue. Subliminally he says,
language tells people to think that anything on the right can be trusted
while anything on the left is dangerous or even sinister. We speak of left-handed
compliments and according to Moore, “it is no coincidence that left-handed
children, forced to use their right hand, often develop a stammer as they are
robbed of their freedom of speech”. However, as more research is undertaken on
the causes of left-handedness, attitudes towards left-handed people are
gradually changing for the better. Indeed when the champion tennis player
Ivan Lendl was asked what the single thing was that he would choose in order
to improve his game, he said he would like to become a lefthander.
Geoff Maslen
|
Questions 1-7
Use the information in the text to match
the people (listed A-E) with the opinions (listed 1-7) below.
Write the appropriate letter (A-E) in boxes 1-7 on your answer sheet.
Some people match more than one opinion.
A
|
Dr Broca
|
B
|
Dr Brinkman
|
C
|
Geschwind and Galaburda
|
D
|
Charles Moore
|
E
|
Professor Turner
|
Example
Monkeys do not
show a species specific preference for left or right-handedness.
|
Answer
B
|
1
|
Human beings started to show a
preference for right-handedness when they first developed language.
|
2
|
Society is prejudiced against
left-handed people.
|
3
|
Boys are more likely to be left-handed.
|
4
|
After a stroke, left-handed people
recover their speech more quickly than right-handed people.
|
5
|
People who suffer strokes on the left
side of the brain usually lose their power of speech.
|
6
|
The two sides of the brain develop
different functions before birth.
|
7
|
Asymmetry is a common feature of the
human body.
|
Questions 8-10
Using the information in the passage,
complete the table below. Write your answers in boxes 8-10 on your answer
sheet.
|
Percentage
of children left-handed
|
One parent
left-handed
One parent
right-handed
|
…… (8) ………
|
Both parents
left-handed
|
…… (9) ………
|
Both parents
right-handed
|
…… (10) ………
|
Questions 11-12
Choose the appropriate letters A-D and
write them in boxes 11 and 12 on your answer sheet.
11
|
A study of
monkeys has shown that
|
A. monkeys
are not usually right-handed.
|
|
B. monkeys
display a capacity for speech.
|
|
C. monkey
brains are smaller than human brains.
|
|
D. monkey
brains are asymmetric.
|
|
12
|
According to
the writer, left-handed people
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A. will often develop a stammer.
|
|
B. have
undergone hardship for years.
|
|
C. are
untrustworthy.
|
|
D. are good
tennis players.
|
ANSWER
KEY
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