IELTS Academic Reading Practice Test 53

Until the middle of the nineteenth century, surgery was an ordeal that patients endured fully conscious. Operations were limited mostly to amputations, the removal of tumours near the surface of the body and the extraction of bladder stones, and a surgeon's reputation depended largely on speed: the faster the cut, the shorter the agony. Alcohol and opium could dull the senses a little, but they did not prevent pain, and many people who needed an operation chose instead to live with their illness or to die of it.

The possibility of a remedy had been glimpsed long before it was put into practice. In 1800 the English chemist Humphry Davy, having experimented on himself with nitrous oxide, observed that the gas appeared capable of relieving physical pain and proposed that it might be useful during surgical operations. The suggestion was not taken up. Instead, nitrous oxide, nicknamed laughing gas, and the vapour of ether became sources of entertainment: travelling lecturers invited members of their audience to inhale them, and so-called ether frolics were popular among students.

Meanwhile, on the other side of the world, the Japanese surgeon Hanaoka Seishū had developed an anaesthetic drink from medicinal plants, and in 1804 he removed a tumour from the breast of a patient who had been made unconscious by it. Because Japan was largely closed to foreigners at the time, his achievement remained unknown in Europe and America.

It was the recreational use of these substances that eventually drew doctors' attention to their medical value. In 1842 Crawford Long, a physician in rural Georgia, noticed that friends who hurt themselves during ether parties seemed to feel nothing, and he used ether while removing a growth from a patient's neck. However, Long did not publish his results until 1849, by which time the credit had gone elsewhere. In Connecticut, a dentist named Horace Wells had one of his own teeth extracted under nitrous oxide in 1844 and was convinced that he had found the answer. Early in 1845 he attempted a public demonstration in Boston, but the patient cried out during the procedure, the audience concluded that the method had failed, and Wells was ridiculed.

Wells's former business partner, William Morton, turned his attention to ether, which was more potent than nitrous oxide. On 16 October 1846, at Massachusetts General Hospital in Boston, Morton administered ether vapour to a young man named Gilbert Abbott, from whose neck the surgeon John Collins Warren then removed a tumour. The patient showed no sign of distress, and Warren announced to the watching doctors that the demonstration was genuine. The lecture theatre in which it took place has been preserved and is known today as the Ether Dome. Morton at first tried to disguise the substance he had used, giving it the name Letheon, because he hoped to profit from a patent, but the secret did not last long.

News travelled with remarkable speed for the age. Within weeks, the physician and writer Oliver Wendell Holmes had suggested in a letter to Morton that the new condition be called anaesthesia, from the Greek for 'without sensation', and by the end of the year ether was being used in London. In Edinburgh, the obstetrician James Young Simpson looked for an alternative, because ether irritated the lungs, often caused vomiting and was highly flammable. In November 1847, after he and his colleagues had tested a series of chemicals on themselves, he introduced chloroform, which was pleasanter to inhale and acted more quickly. Its use in childbirth remained controversial until 1853, when John Snow gave it to Queen Victoria during the birth of her eighth child, Prince Leopold.

The new agents were not without danger. In January 1848 a fifteen-year-old girl, Hannah Greener, died near Newcastle after being given chloroform for a minor operation on her toe, and further deaths followed. Snow studied such cases carefully and argued that many could be avoided if the dose were controlled with a properly designed inhaler rather than a handkerchief. His insistence that anaesthesia required skill and measurement laid the foundations of a medical specialty. Even so, freedom from pain did not make surgery safe: until antiseptic methods were adopted later in the century, many patients who survived an operation died of infection afterwards.

Over the following century the practice was transformed. Anaesthetists learned to pass a tube into the windpipe to keep the airway open, and in 1942 the Canadian anaesthetist Harold Griffith showed that a preparation of curare, a plant poison once used on arrow tips in South America, could relax a patient's muscles during surgery. Intravenous drugs allowed patients to fall asleep within seconds instead of struggling against an unpleasant vapour, and electronic monitors came to track heart rhythm, blood pressure and the level of oxygen in the blood throughout an operation.

A typical general anaesthetic today follows a well-established sequence. Before the operation, the anaesthetist assesses the patient's general health and asks about any previous reactions to drugs. Pure oxygen is then given through a face mask, and an intravenous drug such as propofol is injected to induce unconsciousness. If the muscles need to be relaxed, a muscle relaxant is given and a breathing tube is inserted, after which a ventilator takes over the work of breathing. Unconsciousness is usually maintained with an inhaled agent, and the drugs are stopped as the surgery ends, allowing the patient to wake in a recovery area under close observation.

The crow family, or Corvidae, includes crows, ravens, rooks, jackdaws, jays and magpies, and its members have long had a reputation for cunning in folklore. Corvids are found on every continent except Antarctica, and many species thrive in towns and cities. In recent decades that reputation has been tested in laboratories and in the wild, and the results have been striking enough for two Cambridge researchers, Nathan Emery and Nicola Clayton, to argue in 2004 that the mental abilities of corvids rival those of the great apes. If they are right, the finding is remarkable, because birds and mammals last shared a common ancestor more than 300 million years ago. Any similarity in their reasoning must therefore have evolved independently, through what biologists call convergent evolution.

For a long time, bird brains were considered too small and too simply organised to support complex thought, and the insult 'bird-brained' expresses exactly this assumption. Birds lack the layered cerebral cortex that is associated with intelligence in mammals. The corresponding part of a bird brain is organised differently, as clusters of cells rather than sheets, and the whole organ is tiny in absolute terms. However, a study published in 2016 found that neurons in the forebrains of songbirds and parrots are packed far more densely than those of mammals. As a result, a crow or a parrot may possess as many forebrain neurons as a monkey with a much larger brain, which may help to explain how such small heads can contain such capable minds. Corvids and parrots also have unusually large brains for their body size. In this respect they are more like apes than like most other birds.

The most celebrated tool users in the family are New Caledonian crows, which live only on a group of islands in the south-west Pacific. In the 1990s the biologist Gavin Hunt described how these birds fashion hooked tools from twigs and cut stepped probes from the barbed edges of pandanus leaves, then use them to extract insect larvae from holes in dead wood. The work is careful. To make a hooked stick, a crow first snaps a forked twig from a branch. It then strips away the leaves and bark and sculpts the hook with its bill. Good tools are often carried from one feeding site to another and used again. Different populations on the islands make leaf tools of noticeably different shapes, which some researchers interpret as a form of cultural tradition, with designs passed from one generation to the next and perhaps refined over time.

Laboratory studies have revealed how flexible this ability can be. In 2002 a team at the University of Oxford reported that a captive female crow named Betty, faced with a small basket of food at the bottom of a vertical tube and given only a straight piece of wire, bent the wire into a hook and lifted the basket out. Later research showed that wild crows use a similar bending action when making twig tools, so her behaviour may have been less original than it first appeared. Then, in 2018, researchers found that several crows of the same species, given pieces that were individually too short to reach a reward, spontaneously fitted them together, and one bird built a working tool from four separate parts.

Other experiments have drawn on one of Aesop's fables, in which a thirsty crow raises the level of water in a jug by dropping pebbles into it. When rooks, which do not use tools in the wild, were offered a floating worm in a tube of water just beyond their reach, they dropped stones into the tube until the worm rose high enough to be seized. They also learned quickly that larger stones raised the water faster than small ones. Later versions of the test showed that New Caledonian crows preferred to drop heavy objects rather than light ones that floated, and solid objects rather than hollow ones, suggesting some understanding of how objects displace water. However, the birds failed at a more complex version of the task involving two connected tubes.

Corvids are also exceptionally good at remembering people. In a series of experiments that began in 2006, the American biologist John Marzluff and his colleagues at the University of Washington in Seattle wore a distinctive rubber mask while trapping and ringing a small number of wild crows on the campus, before releasing them unharmed. For years afterwards, crows scolded and mobbed anyone wearing that mask, while largely ignoring people in a different, neutral mask. Strikingly, many of the birds that reacted had never been caught themselves, which indicates that they had learned to recognise the dangerous face by watching other crows.

Some corvids also seem to think about the future and about the minds of others. Western scrub jays that have been watched by another bird while hiding food often return later and move it to a new hiding place, but they generally do this only if they have previously stolen food themselves. Ravens have been shown in experiments to choose a tool that would be useful later, and to keep it for a future task, rather than accepting an immediate but smaller reward. Such experiments are difficult to design, because simpler explanations such as habit or chance must be ruled out. Researchers therefore continue to debate whether the behaviour involves genuine planning, but it has made it much harder to regard sophisticated intelligence as a privilege of primates.

Few marketing techniques are as old, or as expensive, as paying a famous person to praise a product. In the 1760s the potter Josiah Wedgwood, having supplied a tea service to Queen Charlotte, gained permission to call his cream-coloured earthenware Queen's Ware, and he exploited the royal connection tirelessly in his advertising. Today companies spend enormous sums on athletes, actors and musicians, and increasingly on the social-media personalities known as influencers. My argument is not that such spending is wasted, but that it works far less reliably than its enthusiasts assume, and that the conditions under which it succeeds are narrower than many brands seem to realise.

Researchers have offered several explanations of why endorsements might influence buyers. One emphasises credibility: a message is more persuasive when its source seems expert, trustworthy or attractive. Another, proposed by the anthropologist Grant McCracken in 1989, holds that celebrities carry cultural meanings, such as glamour, toughness or sophistication, which are transferred first to the product and then, when it is bought, to the consumer. A third, known as the match-up hypothesis, predicts that an endorsement works best when there is an obvious fit between the star and the product, as when an athlete promotes sports equipment rather than, say, insurance. Each of these theories captures part of the truth, but none of them guarantees that a particular endorsement will repay its cost.

The most celebrated success appears to confirm this last idea. In 1984 the sportswear company Nike signed a young basketball player, Michael Jordan, and the following year launched a shoe bearing his name. The Air Jordan line became one of the most valuable franchises in the history of the industry, and it now operates almost as a brand in its own right. Yet it would be a mistake to treat such a case as typical. Jordan became arguably the most admired athlete in the world, and Nike invested heavily in design and advertising around him; most endorsement deals involve neither an exceptional star nor that level of commitment.

Systematic research gives a more modest picture. A study by Anita Elberse and Jeroen Verleun, published in 2012, examined a large number of endorsement deals involving athletes and found that, on average, they were associated with increases in both sales and the stock-market value of the companies concerned. Importantly, however, the sales gains tended to diminish over time, and they rose noticeably whenever the athlete won a major title. This suggests that much of the benefit depends on the endorser's continuing success, which is something no company can control. Averages, moreover, inevitably conceal wide differences between individual deals.

That lack of control is the most obvious danger. When a celebrity's reputation collapses, the brands associated with them can suffer as well. After the golfer Tiger Woods became the subject of a highly publicised personal scandal at the end of 2009, two economists at the University of California, Davis, estimated that the shareholders of his sponsors had lost between five and twelve billion dollars in value within a few weeks. Some sponsors ended their contracts, while others stood by him. Contracts now routinely include morality clauses allowing a company to withdraw if its endorser behaves badly, but such clauses can limit the financial damage only after it has occurred.

A subtler problem is that a famous face may draw attention to itself rather than to the product. Advertising practitioners sometimes describe this as the vampire effect: viewers remember the star but not the brand. People who enjoy an advertisement may therefore fail to connect it with the company that paid for it. Celebrities who endorse many products at once compound the difficulty, since each additional deal weakens the association with any single one, and audiences increasingly suspect that the endorser is motivated by the fee rather than by genuine enthusiasm. In my view, this scepticism is entirely rational, and companies would be wise to assume that consumers are more discerning than they once were.

The growth of social media has altered the field without removing these problems. Influencers with modest audiences may seem more authentic than distant stars, and some marketers argue that their recommendations feel like advice from a friend. But that sense of intimacy is precisely what makes undisclosed payment troubling, and regulators in many countries now require paid promotions to be clearly labelled.

In 2022 the reality-television personality Kim Kardashian agreed to pay 1.26 million dollars to settle charges brought by the US Securities and Exchange Commission, which said that she had promoted a cryptocurrency on Instagram without disclosing that she had been paid 250,000 dollars to do so. I welcome such enforcement, because an endorsement whose commercial nature is hidden is not persuasion but deception.

None of this means that companies should abandon endorsements. When a well-chosen figure has a natural connection with a product, and the relationship is presented honestly and sustained over many years, the results can be valuable. But the evidence suggests that the endorser is rarely the main reason a product succeeds. Quality, price and distribution still matter more, and a brand that relies on borrowed fame to compensate for weaknesses elsewhere is likely to be disappointed. The most effective endorsements, in my judgement, are those in which the endorser genuinely uses and values the product, so that the implied claim is actually true.