# Left or right?: answers and explanations

The Official Cambridge Guide to IELTS, Test 8, Reading Passage 3

Source: Passage, questions and answer key from The Official Cambridge Guide to IELTS, Test 8, Reading Passage 3. © Cambridge University Press & Assessment. Used for educational practice. Explanations and evidence notes are written by Testmigo.

## Answer key

| Q | Answer | Proof |
| --- | --- | --- |
| 27 | D | For many years it was assumed that lateralisation was a uniquely human trait ... was surprised to observe that the chemical only worked when applied to the left hemisphere of the brain. |
| 28 | C | strongly-lateralised individuals were able to feed twice as fast as weakly-lateralised ones when there was a threat of a predator looming above them. |
| 29 | E | the parrots with the strongest foot preferences worked out the puzzle far more quickly than their ambidextrous peers. |
| 30 | B | while a very small proportion of the group escape in the direction that the predator is not expecting. |
| 31 | environmental | but environmental factors have an impact too. |
| 32 | light | Rogers found that a chick's lateralisation depends on whether it is exposed to light before hatching from its egg |
| 33 | multitasking | Rogers used this observation to test the advantages of brain bias in chicks faced with the challenge of multitasking. |
| 34 | food | the birds incubated in the light looked for food mainly with their right eye |
| 35 | predator | while using the other to check out the predator. |
| 36 | E | Similar results probably hold true for many other animals. |
| 37 | H | It has been suggested that when it comes to hand-to-hand fighting, left-handers may have the advantage over the right-handed majority. |
| 38 | B | researchers have built up an impressive catalogue of animal lateralisation. |
| 39 | B | but this notion rapidly fell apart as researchers started uncovering evidence of lateralisation in all sorts of animals. |
| 40 | A | So why would animals evolve a characteristic that seems to endanger them? |

## Why these answers are right

**27. D.** Paragraph B presents Rogers' 1970s chick research as early evidence against the belief that lateralisation was uniquely human, since her chemical worked only in the left hemisphere. Her finding shows lateralisation is not confined to humans, which is ending D.

**28. C.** Paragraph E reports Bisazza's fish study: strongly lateralised fish fed twice as fast as weakly lateralised ones while a predator loomed overhead. Feeding while watching for danger means doing two things at once, so ending C fits; problem-solving belongs to the parrots.

**29. E.** In Paragraph F, Magat and Brown gave parrots a demanding string-pulling puzzle, and the birds with the strongest foot preferences solved it far faster than ambidextrous ones. So the greater the lateralisation, the better the problem-solving, which is ending E.

The why and the trap for questions 30 onwards are free with an account on the [answers page](https://testmigo.com/ielts/reading/left-or-right/answers).

[Practice Left or right?](https://testmigo.com/ielts/reading/left-or-right)