The passage contains following question types from IELTS Reading Question Types:
- Complete the sentences.
- True False Not Given Questions.
Numeracy: can animals tell numbers?
You should spend about 20 minutes on Questions 1 – 13 which are based on Reading Passage below.
Prime among basic numerical faculties is the ability to distinguish between a larger and a smaller number, says psychologist Elizabeth Brannon. Humans can do this with ease – providing the ratio is big enough – but do other animals share this ability? In one experiment, rhesus monkeys and university students examined two sets of geometrical objects that appeared briefly on a computer monitor. They had to decide which set contained more objects. Both groups performed successfully but, importantly, Brannon’s team found that monkeys, like humans, make more errors when two sets of objects are close in number. The students’ performance ends up looking just like a monkey’s. It’s practically identical,’ she says.
Humans and monkeys are mammals, in the animal family known as primates. These are not the only animals whose numerical capacities rely on ratio, however. The same seems to apply to some amphibians. Psychologist Claudia Uller’s team tempted salamanders with two sets of fruit flies held in clear tubes. In a series of trials, the researchers noted which tube the salamanders scampered towards, reasoning that if they had a capacity to recognise number, they would head for the larger number. The salamanders successfully discriminated between tubes containing 8 and 16 flies respectively, but not between 3 and 4, 4 and 6, or 8 and 12. So it seems that for the salamanders to discriminate between two numbers, the larger must be at least twice as big as the smaller. However, they could differentiate between 2 and 3 flies just as well as between 1 and 2 flies, suggesting they recognise small numbers in a different way from larger numbers.
Further support for this theory comes from studies of mosquitofish, which instinctively join the biggest shoal* they can. A team at the University of Padova found that while mosquitofish can tell the difference between a group containing 3 shoal-mates and a group containing 4, they did not show a preference between groups of 4 and 5. The team also found that mosquitofish can discriminate between numbers up to 16, but only if the ratio between the fish in each shoal was greater than 2:1. This indicates that the fish, like salamanders, possess both the approximate and precise number systems found in more intelligent animals such as infant humans and other primates.
While these findings are highly suggestive, some critics argue that the animals might be relying on other factors to complete the tasks, without considering the number itself. ‘Any study that’s claiming an animal is capable of representing number should also be controlling for other factors,’ says Brannon. Experiments have confirmed that primates can indeed perform numerical feats without extra clues, but what about the more primitive animals?
To consider this possibility, the mosquitofish tests were repeated, this time using varying geometrical shapes in place of fish. The team arranged these shapes so that they had the same overall surface area and luminance even though they contained a different number of objects. Across hundreds of trials on 14 different fish, the team found they consistently discriminated 2 objects from 3. The team is now testing whether mosquitofish can also distinguish 3 geometric objects from 4.
Even more primitive organisms may share this ability. Entomologist Jurgen Tautz sent a group of bees down a corridor, at the end of which lay two chambers – one which contained sugar water, which they like, while the other was empty. To test the bees’ numeracy, the team marked each chamber with a different number of geometrical shapes – between 2 and 6. The bees quickly learned to match the number of shapes with the correct chamber. Like the salamanders and fish, there was a limit to the bees’ mathematical prowess – they could differentiate up to 4 shapes, but failed with 5 or 6 shapes.
These studies still do not show whether animals learn to count through training, or whether they are born with the skills already intact. If the latter is true, it would suggest there was a strong evolutionary advantage to a mathematical mind. Proof that this may be the case has emerged from an experiment testing the mathematical ability of three- and four-day-old chicks. Like mosquitofish, chicks prefer to be around as many of their siblings as possible, so they will always head towards a larger number of their kin. If chicks spend their first few days surrounded by certain objects, they become attached to these objects as if they were family. Researchers placed each chick in the middle of a platform and showed it two groups of balls of paper. Next, they hid the two piles behind screens, changed the quantities and revealed them to the chick. This forced the chick to perform simple computations to decide which side now contained the biggest number of its “brothers”. Without any prior coaching, the chicks scuttled to the larger quantity at a rate well above chance. They were doing some very simple arithmetic, claim the researchers.
Why these skills evolved is not hard to imagine, since it would help almost any animal forage for food. Animals on the prowl for sustenance must constantly decide which tree has the most fruit, or which patch of flowers will contain the most nectar. There are also other, less obvious, advantages of numeracy. In one compelling example, researchers in America found that female coots appear to calculate how many eggs they have laid – and add any in the nest laid by an intruder – before making any decisions about adding to them. Exactly how ancient these skills are is difficult to determine, however. Only by studying the numerical abilities of more and more creatures using standardised procedures can we hope to understand the basic preconditions for the evolution of number.
Complete the table below.
Choose NO MORE THAN THREE WORDS from the passage for each answer.
Write your anwsers in boxes 1-7 on your anwer sheet.
|Mammals and birds|
|rhesus monkeys and humans||looked at two sets of geometrical objects on computer screen||performance of two groups is almost 1) … ….|
|chicks||chose between two sets of 2) ……which are altered||chicks can do calculations in order to choose larger group|
|coots||the behaviour of 3)…….. birds was observed||bird seems to have the ability to count eggs|
|Amphibians, fish and insects|
|salamanders||offered clear tubes containing different quantities of 4) ………..||salamanders distinguish between numbers over four if bigger number is at least two times larger|
|5) ……………||shown real shoals and later artificial ones of geometrical shapes; these are used to check the influence of total 6) ….. and brightness||subjects know difference between two and three and possibly three and four, but not between four and five|
|bees||had to learn where 7)….. was stored||could soon choose correct place|
Do the following statements agree with the information given in Reading Passage 1?
In boxes 8-13 on your answer sheet, write
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this
8) Primates are better at identifying the larger of two numbers if one is much bigger than the other.
9) Jurgen Tautz trained the insects in his experiment to recognise the shapes of individual numbers.
10) The research involving young chicks took place over two separate days.
11) The experiment with chicks suggests that some numerical ability exists in newborn animals.
12) Researchers have experimented by altering quantities of nectar or fruit available to certain wild animals.
13) When assessing the number of eggs in their nest, coots take into account those of other birds.
ANSWERS (CLEAR EXPLANATION) FOR IELTS READING PRACTICE TEST 24
(The table is arranged in a logical way, but the information is not in exactly the same order as it is given in the passage.)
1) identical: The first paragraph says ‘The students’ performance ends up looking just like a monkey’s. It’s practically [= almost] identical’.
2) balls of paper: The sixth paragraph says ‘… showed it two groups of balls of paper … changed the quantities’ (although the text mentions ‘siblings’ and ‘brothers’, the experiment did not use other chicks).
3) female: The last paragraph says ‘researchers in America found that female coots appear to calculate’ (the text also mentions ‘an intruder’, but it was the ‘counting’ behaviour/behavior of the coots that the researchers were interested in).
4) fruit flies: The second paragraph says ‘tempted salamanders with two sets of fruit flies held in clear tubes’.
5) mosquito fish: The third paragraph says ‘studies of mosquitofish, which instinctively join the biggest shoal’.
6) surface area: The fourth paragraph says ‘The team arranged these shapes so that they had the same overall [= total] surface area and luminance [= brightness] …’.
7) sugar water: The fifth paragraph says ‘two chambers – one which contained sugar water, which they like, while the other was empty. … The bees quickly learned … the correct chamber’.
(Questions 8-13 come in the same order as the information in the passage.)
8) TRUE: The first paragraph says ‘rhesus monkeys and university students … had to decide which set contained more objects…. monkeys, like humans, make more errors when two sets of objects are close in number’; primates are defined in the second paragraph:‘Humans and monkeys are mammals, in the animal family known as primates.’
9) FALSE: The fifth paragraph says ‘the number of shapes [= how many shapes, not the actual shape of individual numerals]’.
10) NOT GIVEN: Although the sixth paragraph says ‘If chicks spend their first few days surrounded by certain objects’, this is a general statement, not how long the experiment lasted; ‘three- and four-day-old chicks’ tells us the age of the chicks, but it does not say that the experiment took place on two days; we do not know whether it was repeated on more than one day.
11) TRUE: The sixth paragraph says that these were almost newborn ‘three- and four-day-old chicks’ and that they ‘scuttled [= ran] to the larger quantity at a rate well above chance. They were doing some very simple arithmetic, claim the researchers’.
12) NOT GIVEN: Although the last paragraph says ‘Animals on the prowl … decide which tree has the most fruit, or which patch of flowers will contain the most nectar’ and that this would be an ‘obvious advantage[s] of numeracy’, we are not told whether any researchers have carried out experiments involving the animals searching for these foods.
13) TRUE: The last paragraph says ‘female coots appear to calculate … and add any in the nest laid by an intruder [= another bird]’.