IELTS Academic Reading Practice Test 451

Ghadames, an oasis town in the south-west of Libya, stands close to the point where the country's borders with Algeria and Tunisia meet. It is surrounded on every side by stony desert, and the nearest sizeable settlement is hundreds of kilometres away. Travellers who reached it in earlier centuries called it the pearl of the desert, a name that still appears in guidebooks and on official signs. Its old town, a dense cluster of mud-brick houses enclosed by a wall, was added to the UNESCO World Heritage List in 1986.

The reason for the town's existence is water. Several springs rise in the oasis, and around them grow tens of thousands of date palms, together with figs, olives and vegetables. Without these springs no permanent settlement could have been possible, since rainfall in the region is negligible and may fail altogether for several years in succession. The gardens were traditionally irrigated by a system of channels that distributed water to each plot in turn, a method found in oases across North Africa, and the groves are still worked by families who inherited particular plots.

Water made life possible; trade made the town rich. Ghadames lay at the crossing of routes that linked the Mediterranean coast with the trading cities of the Sahel, and the caravans that passed through carried salt, gold, ivory and slaves, along with cloth and metal goods from the north. Because a caravan could take weeks to cross the desert, the town became a place where goods were stored, sorted and taxed before travelling on. For centuries its merchants were among the most prosperous in the Sahara, and their wealth paid for the mosques, schools and houses that still stand. The town's fortunes declined in the twentieth century, as motor vehicles and later aircraft replaced the camel, and as national borders and customs posts made movement across the desert harder.

What visitors notice first is the colour. The houses are built of mud brick, lime and palm trunks, all of them taken from the oasis itself, and their walls are whitewashed or left the pale gold of the surrounding earth. Because the summer sun is fierce, the streets between the houses are narrow and many of them are covered with vaulted roofs, so that a walk through the old town can be made almost entirely in shade. The thick walls hold the cool of the night well into the afternoon.

Inside, a house is arranged vertically. The ground floor, entered from a dark passage, is used for storage; above it are rooms for living and sleeping, and at the top is a terrace open to the sky. This arrangement is more than a response to the climate. The terraces of neighbouring houses are joined together, forming a continuous network of walkways above the streets, and it was along these that women could visit one another without being seen by men outside the family. Anthropologists who have studied the town treat this upper level as a separate, largely female domain, and older residents still remember it as such.

The old town also contains a number of mosques, the largest of which has a tall, square minaret visible above the palm groves, and each quarter had its own small square where news was exchanged and goods were sold. The whole settlement is enclosed by a wall pierced by a few gates, a reminder that raids from the desert were once a real danger and that the oasis, for all its isolation, was never entirely peaceful.

Ghadames has one of the harshest climates in the Sahara. Summer daytime temperatures routinely exceed 40°C, and the annual rainfall is only a few millimetres, so that a year may pass without a shower of any consequence. Winters are mild by day but cold at night, and sand-laden winds blow in spring. Visitors often remark that the town feels cooler than the desert around it, which is precisely what its builders intended.

In the 1970s and 1980s the Libyan government built a new town a short distance away, with piped water, electricity, schools and a hospital, and most families moved there. The old houses were kept on by their owners, many of whom returned in the summer, but for much of the year the streets stood empty. UNESCO has repeatedly expressed concern about the condition of the site: an abandoned mud-brick building collapses quickly once rain has entered its walls, and several have already been lost.

Flash floods have also caused damage, and a lack of maintenance has affected the network of roof walkways, which loses its waterproof outer layer within a few seasons if it is not renewed. Restoration work has been carried out with international support, using local craftsmen trained in traditional methods of mixing earth and lime. Political instability since 2011 has greatly reduced the number of foreign visitors, however, and the income from tourism on which some restoration plans depended has largely disappeared.

The town's culture survives, partly because the old quarter is still used. Many families regard the move to modern housing as a matter of convenience rather than a break with the past, and return for weddings, religious festivals and the date harvest. Ghadamès, the local Amazigh language, is still spoken, though its speakers are few and younger people increasingly use Arabic. Whether the buildings can be preserved while the community that understands them lives elsewhere is the question that now preoccupies conservationists.

Most people believe they can tell when someone is lying. The evidence suggests otherwise. In experiments, volunteers watch or listen to people describing events and judge whether each account is true, and their results are consistently unimpressive. This is not because lies are rare. Surveys in which people keep diaries of their own dishonesty, and laboratory studies in which participants are tempted to cheat, both suggest that small lies are a routine part of social life. Nor is it a matter of intelligence or education: studies have found that judges, police officers and customs officials do no better than students. The interesting question is why a skill that matters so much should be so poorly developed.

Popular beliefs about lying are remarkably consistent. Liars, it is said, avoid eye contact, fidget, touch their faces and give themselves away through the pitch of their voices. When researchers have tested these beliefs, most have found little support for them. A review of the experimental literature concluded that liars do not look away more than truth-tellers; indeed, some studies find the opposite, because a liar who has prepared an answer may deliberately hold the questioner's gaze. When the results of many studies are combined, the behavioural differences between honest and dishonest people turn out to be small and easily disturbed by individual habits.

The best-known estimate of human accuracy comes from a statistical review that pooled the results of more than two hundred experiments. Its authors found that people correctly identified lies about 54 per cent of the time, a figure barely above what guessing would produce. The same review, and much subsequent work, found that people are biased towards believing what they are told: truth-tellers are identified correctly far more often than liars. This tendency, which one researcher has named the truth-default, is not simply a weakness. Social life would be impossible if every statement were treated with suspicion, and a degree of trust is what makes cooperation, trade and friendship possible at all.

Why should deception be so hard to see? The main reason is that there is no single sign of lying. People lie for different reasons, in different moods, about different things, and the behaviour that accompanies a lie depends on all of these. Some liars are anxious, but so are many nervous truth-tellers; some are confident, because they have rehearsed. The psychologist Paul Ekman drew attention to microexpressions, fleeting changes in the face that appear for a fraction of a second and may reveal an emotion that a person is trying to conceal. Training people to notice them has become a small industry, yet the evidence that it produces reliable lie detection remains thin, and Ekman himself warned that most people, however experienced, perform little better than chance.

A more promising line of work examines not the body but the words. Detailed accounts of real experiences tend to contain sensory detail, unusual features, references to time and place, and acknowledgements of uncertainty; invented accounts are often thinner and more orderly than the events they describe. A set of criteria along these lines, developed in Germany and known as criteria-based content analysis, is used in some European legal systems to help assess statements, particularly those made by children. Its results are useful but far from decisive, and it requires trained assessors and a written record long enough to analyse in detail. Assessors are also trained to allow for the age and background of the person speaking.

Others have tried to make lying harder rather than to spot it. If lying demands more mental effort than telling the truth, the reasoning goes, then adding to that effort should widen the gap between them. In experiments by the psychologist Aldert Vrij and his colleagues, interviewees have been asked to recount events in reverse chronological order, to describe a scene from the viewpoint of another person, or to answer unexpected questions while performing a second task. Liars do perform worse under these conditions. Yet reviews of the studies have found the gains in accuracy to be modest, and the techniques appear to work best for short, specific events rather than lengthy, complicated ones.

Machines have a long history in this field, with mixed results. The polygraph, the best known of them, records breathing, pulse, blood pressure and the skin's capacity to conduct electricity. It does not detect lies; it detects arousal, and it cannot distinguish the anxiety of a liar from the anxiety of an innocent person who is frightened of being disbelieved. Voice stress analysis, marketed as a simpler alternative, has been tested repeatedly and found to be no better than chance. Brain scanning has attracted commercial interest, but the methods remain experimental and have been excluded from most courts.

Where does this leave the police officer, the border official or the employer? Reviews of training programmes suggest that experience alone does not improve accuracy and may even increase confidence without increasing skill. What does help, modestly, is a structured approach: interviewing at length, asking open questions, keeping an open mind and looking for independent evidence. In the end, no device and no technique can substitute for the patient gathering of corroborating evidence, and the most useful lesson of the research may be a degree of humility about our own judgement. This is an uncomfortable conclusion for organisations that have invested in equipment and training, and it explains why simple technological fixes keep being proposed.

Rich countries are ageing and short of particular skills. Hospitals advertise for nurses from abroad, technology firms recruit engineers, and universities compete for the same postgraduate students. Governments have responded by creating routes that make it easier for the highly skilled to arrive: points systems that award credit for qualifications, language ability and age; visas tied to a job offer; fast-track schemes for occupations on a shortage list; and tax breaks designed to tempt back citizens who have worked abroad. The language of competition is used by ministers in Canada, Australia, Germany and the United Kingdom alike. Those countries are not merely admitting skilled workers; they are bidding for them.

The worry is that this competition redistributes talent rather than creating it. When a nurse trained at public expense in a low-income country takes a job in a rich one, the country that paid for the training loses the return on its investment, and the hospital that employed the nurse loses a colleague. The problem is sharpest in health care, where the shortages in rich countries are matched by deeper shortages in poor ones, and where a few destination countries account for many of those who leave. The World Health Organization adopted a global code in 2010 on how health workers should be recruited across borders, asking countries to recruit ethically and to avoid actively drawing staff from systems that can least afford to lose them.

Against this, economists point out that the picture is not simply one of loss. The prospect of working abroad raises the return to training, and in some countries it has encouraged more people to qualify than would otherwise have done so; some of them never leave, and others return with skills and savings. Money sent home by migrants is substantial: remittances to low- and middle-income countries have exceeded the total of official development assistance in recent years. Diaspora networks transfer knowledge, contacts and investment. This argument, known as beneficial brain drain, is taken seriously, though its force varies greatly between occupations. A software engineer may be replaced fairly quickly; a surgeon cannot be.

The market for skilled labour is not like the market for goods. In the short term at least, the supply of surgeons, anaesthetists and specialist nurses is fixed, because training takes years and is limited by the number of places that universities and hospitals can offer. If one rich country does not recruit a particular doctor, another will. Competition between destination countries may therefore raise the price of scarce skills without increasing the number of people who possess them. Several economists have proposed that destination countries should compensate source countries, through a tax on the earnings of skilled emigrants, an idea associated with the economist Jagdish Bhagwati, or through payments towards the cost of training.

What might destination countries do instead? Three proposals recur. The first is to train more of their own staff, rather than relying on imported labour to fill the gap; critics note that rich countries have sometimes cut domestic training places while continuing to recruit abroad. The second is to recruit under agreed rules, using ethical codes and bilateral agreements that allow some movement while protecting the health system of the country of origin. The third is to invest directly in training in source countries, so that the number of qualified staff rises overall rather than being redistributed. None of this is easy: training at home is expensive, and agreements depend on employers' willingness to respect them.

A further consideration is often absent from these calculations. Skilled workers are not resources to be allocated by governments but people with their own plans and obligations. The right to leave one's own country is recognised in international law, and proposals to restrict it, however well intentioned, sit awkwardly with liberal principles. It is also a mistake to assume that migrants always benefit. Many who move find work below their qualifications, because their degrees are not recognised or their language is judged insufficient, a waste of talent that has been called brain waste. The interests of the migrant are identical with neither the sending nor the receiving state.

Does competition between destination countries do any good? Ministers present it as a way of securing advantage in a global economy, and there is something to be said for policies that are open rather than covert. But competition of this kind tends to concentrate on a narrow list of occupations that are already well paid, and it can distract attention from the less glamorous work of building domestic training capacity. It may also generate a bidding war whose main beneficiaries are recruitment agencies and the already well qualified. Bilateral agreements, which link movement to training and to return, have a better record, though the evidence base remains small.

My own view is that the language of competition is misleading. Countries are not competing to produce more skilled workers; for the most part they are competing to attract a share of a pool that grows slowly. In the short term this is close to a zero-sum game, and one in which the poorest countries have most to lose. That does not mean that skilled migration should be restricted, which would be both illiberal and impractical. It means that rich countries should expand their own training, recruit under rules that protect vulnerable health systems, and treat migration as a stage in a career rather than a final transfer. The competition itself is not the problem; the assumption that it can substitute for investment is.