IELTS Academic Reading Practice Test 423

In the hot, dry interior of Iran, travellers sometimes come across an extraordinary structure: a vast cone of pale mud brick, more than ten metres high, standing alone beside a village. This is a yakhchāl, a type of ice house developed in Persia that allowed communities to keep ice and snow through the hottest months of the year. The buildings were in use for many centuries, storing ice and often food long before electric refrigeration existed, and dozens of them can still be seen in the plateau towns of central Iran.

The technique seems to have originated in Persia perhaps as early as the fourth century BCE, in a region where engineers were already skilled at carrying water underground through tunnels called qanats. Dating individual structures is difficult, and most of those that survive were built much later, during the seventeenth, eighteenth and nineteenth centuries, when the ice trade was at its height.

Above ground, the dominant feature is the dome. It is constructed from mud brick, or adobe, and its shape is not merely decorative. A curved surface presents only a small area to the sun when the sun is at its highest, and the enormous mass of the walls, which may be two metres thick at the base, absorbs heat slowly and gives it out long after sunset. Openings were kept to a minimum, and the outer surface was coated with a mortar that shed rain and resisted the wind.

The coating, known as sarooj, was a closely guarded mixture. Recipes differ from one account to another, but they generally combine clay, sand and lime with small amounts of materials such as egg white, ash and goat hair. The result was water-resistant and remarkably durable, and it helps to explain why so many ice houses are still standing in a climate that reduces ordinary mud-brick walls to rubble within a few generations. Builders passed the recipe from one generation to the next, and in some families the knowledge was treated as a form of inheritance.

Beneath the dome lies the part that did the real work: a deep pit excavated below the level of the surrounding ground. At a certain depth the soil stays close to a constant temperature all year, and since cold air is heavier than warm air it settles in the chamber and stays there. Blocks of ice were carried down a staircase and stacked inside, where they were covered with straw and other insulating material. Meltwater drained away through a channel in the floor rather than collecting around the ice. The walls of the pit were often lined with brick, which prevented loose earth from falling onto the stored ice.

Some ice houses were also fitted with a tall tower, the badgir or windcatcher, whose open face was turned towards the prevailing wind. The tower captured air moving above the roof and directed it down into the building. On the way the air passed over a shallow pool, and evaporation cooled it further. Windcatchers had been used for centuries to ventilate houses in the same towns, and adding one to an ice house lowered the temperature in the storage pit and slowed the melting of its contents.

Producing the ice in the first place required just as much ingenuity. In winter, water from a qanat was led into shallow channels beside the building. Long, high walls, in some places hundreds of metres in length, ran from east to west so that the ground immediately to their north lay in shadow for most of the day. On cold, clear nights the water in the channels froze, and the thin sheets of ice were broken up and carried into the pit before the sun rose. In some districts snow was brought down from the mountains and packed into the chamber instead.

Ice was not a luxury reserved for cooling drinks. It kept meat and dairy produce fresh, it was sold for making sherbet, and it was used to preserve medicines. Some ice houses stood beside caravanserais, the roadside inns where merchants and their animals rested, and the trade employed labourers who made and stored ice in winter and sold it in the heat of summer. Owners of the larger ice houses could thus earn money in two seasons rather than one.

The buildings fell out of use during the twentieth century, as mechanical refrigeration spread through Iranian towns and cities. Once ice could be made in a kitchen, there was little reason to cut it from a frozen channel in January, and many ice houses were simply abandoned. Rainwater entered cracks in the brickwork, froze in winter and forced the masonry apart, while new streets and houses spread over the land where the freezing channels had once been. Some were used as rubbish dumps, and others lost their domes altogether.

In the past two decades, however, the survivors have attracted fresh attention. Architects study them as examples of passive cooling, in which a building maintains a low internal temperature without powered machinery. The historic city of Yazd, with its ice houses, windcatchers and qanats, was added to the UNESCO World Heritage List in 2017, and several ice houses have since been repaired and opened to visitors. Conservators now face the difficult task of repairing mud-brick domes with materials that behave as the original ones did.

A rumour is a piece of information passed from person to person without any reliable evidence of its truth. Everyone has taken part in spreading one, usually without meaning harm, and most rumours die out after a few conversations. A small number, however, travel enormous distances, and understanding why has occupied psychologists, mathematicians and, more recently, computer scientists. Their work suggests that the spread of a rumour depends less on whether it is true than on how well it fits the anxieties of the people who hear it, and on how easily they can check it.

The first systematic study of the subject was carried out during the Second World War, when American newspapers, helped by university researchers, set up rumour clinics to monitor and answer false stories circulating on the home front. Out of this work came a book published in 1947 by the psychologists Gordon Allport and Leo Postman, who proposed what they called the basic law of rumour: the strength of a rumour depends on its importance to the people concerned multiplied by the ambiguity of the evidence available. If a story matters greatly and nobody knows the facts, it will spread; if either factor is missing, it will not.

Allport and Postman also experimented with what they called serial reproduction. A volunteer was shown a picture and asked to describe it to a second person, who described it to a third, and so on along a chain. The stories changed in consistent ways. Details that did not fit the teller's expectations were dropped, a process the researchers called levelling, while the features that remained were exaggerated and sharpened. The final version was usually shorter, more dramatic and more convenient for the teller than the original. Similar experiments have been repeated many times since, with broadly similar results.

In the 1960s two mathematicians, D. J. Daley and D. G. Kendall, borrowed the mathematics used to describe epidemics and applied it to rumours. In their model a population is divided into those who have not heard the story, those who are actively passing it on, and those who have heard it but lost interest and stopped. A rumour spreads when spreaders meet people who have not heard it, and it dies out when spreaders meet each other or meet people who have already stopped listening. Later versions added further categories, but the central insight survived: a rumour behaves like an infection that eventually runs out of susceptible people.

The shape of the network matters as much as the psychology of individuals. Studies of how people are connected have repeatedly found that a small number of highly connected individuals sit at the centre of many social circles, and that information passing through them reaches far more people than information that stays among close friends. The same research shows the importance of acquaintances rather than intimates: because our close friends tend to know one another, it is the occasional contact, who moves between separate groups, that carries a story into new territory. This is one reason why the old idea that a rumour travels from the mass media to influential people and then to everyone else has been revised.

Digital networks have changed the scale of the process. A message can now reach millions of people within hours, and the networks through which it passes leave a record that can be analysed. A widely cited study published in 2018 examined a large collection of messages on a social media platform and concluded that false stories spread faster, further and more widely than true ones. Its authors also found that the difference was caused mainly by human behaviour rather than by automated accounts: people were more willing to share claims that surprised them or aroused strong emotion.

If false stories travel so easily, can they be corrected? Not as easily as one might hope. A body of experiments has established what psychologists call the continued influence effect: when a claim is repeated and then withdrawn, people often continue to rely on it when making judgements, even when they remember and accept the correction. Familiarity is part of the explanation, since a statement heard many times feels truer than one heard once, and repeating a falsehood in order to deny it can therefore strengthen it.

What remains genuinely uncertain is prediction. Researchers can describe, in general terms, the conditions under which rumours flourish, but they cannot yet say in advance which of the thousands of stories that appear on a given day will travel across the world. The data are held by companies that rarely share them, the systems change quickly, and laboratory experiments on how people pass on information cannot easily be scaled up to a global network. Whether a single influential account or a large number of ordinary users is decisive in any particular case remains disputed.

For practical purposes, however, some conclusions are reasonably secure. Corrections work better when they offer an alternative explanation rather than simply denying the false claim, when they come from a source the audience already trusts, and when they arrive early. Above all, the research suggests that the most effective response to a rumour is not censorship but a supply of clear, timely information that leaves less room for ambiguity to do its work. Silence, in other words, is not neutral: it allows the most alarming version of events to circulate unanswered.

Jaywalking is one of the few offences that a person can commit simply by walking. The word is an American coinage of the early twentieth century, and in the 1920s motoring organisations campaigned to keep pedestrians off the carriageway while city governments began requiring them to cross at marked points. Before the motor car, streets were shared space where people walked and traded, and the idea that a pedestrian needed permission to cross would have seemed absurd. Today the rules differ widely. Britain has no general offence of crossing outside a marked place; many American cities retain one, though it is enforced sporadically. The question is whether the offence serves any useful purpose.

Most pedestrians treat the law as advice rather than command. People cross where the pavement ends, where a shop or bus stop lies, or where the wait at a signal feels unreasonable, and they do so in every country that has tried to stop them. Surveys consistently find that many pedestrians admit to crossing against a signal. This is not simply disobedience. A crossing that forces someone to walk two hundred metres out of their way, or to stand at an empty road at midnight, asks for a compliance few people are willing to give. Practice has already decided the matter.

Civil-liberties groups go further and argue that the offence is wrong in principle. Movement on foot is the most basic form of access to a city, and a state which turns an ordinary and harmless act into a matter for the police has overstepped its role. A person who crosses a quiet street without causing danger has done nothing to deserve a fine. In practice such laws give officers a reason to stop people who have done nothing else wrong, and the discretion this creates is difficult to keep free of prejudice. The offence, they say, is not a safety measure but a licence for arbitrary intervention.

Road-safety campaigners resist this. They accept that most crossings are harmless, but argue that the law exists for the minority of cases in which a pedestrian steps into traffic without looking, and that removing it would send the wrong signal. Children are their strongest example: a small child cannot judge the speed of an approaching car, and a rule that adults cross at a particular place makes it easier to teach children what to do. Campaigners also note that pedestrians are the most vulnerable road users, with no metal shell to absorb an impact.

Urban planners tend to regard the whole argument as a distraction. In their view the danger lies in the design of streets and the speed of vehicles, not in the timing of a pedestrian's decision. The chance of surviving a collision falls steeply as the speed of the car rises from twenty to fifty kilometres an hour. Where speeds are low and pavements wide, people cross wherever they like and the casualty rate remains modest. The Dutch engineer Hans Monderman went further, arguing that removing signs and markings from some junctions forces drivers and pedestrians to negotiate with each other. His ideas remain contested, but they shift attention from the offender to the environment.

Police representatives describe a different problem: enforcement. A law that requires officers to stop large numbers of people for brief and ordinary behaviour is expensive, unpopular and difficult to apply consistently. In practice it is enforced when an officer happens to see an offence, so it falls hardest on people visible in public space, including the young, the poor and minorities. Stopping pedestrians for a minor infringement can also damage the relationship between the police and the communities they serve. Many forces therefore treat jaywalking as a low priority, and the law remains on the statute book while being largely ignored.

Other countries offer a natural experiment. In Britain, pedestrians may cross wherever they choose except on motorways, and the sky has not fallen. In much of continental Europe the rules are stricter, requiring people to use a crossing when one is close, yet enforcement is light and drivers are trained to expect people in the road. What distinguishes safer countries is not the severity of their pedestrian laws but the design of their streets: lower speed limits in built-up areas, wide pavements, and crossings placed where people actually want to walk.

None of this means that every rule should go. Motorways and high-speed roads are no place for pedestrians, and a red light at a busy junction is a sensible instruction that protects everyone. Children need more protection than adults, and schools are right to teach them to use crossings. Nor should decriminalisation be confused with impunity for drivers: the person who fails to give way at a crossing, or who drives too fast for the conditions, creates the danger. The argument is about who bears the burden of the law, not about whether care matters.

My own view is that the offence of jaywalking should be abolished for adults. The harms it prevents are modest and largely covered by other laws, while the costs, in unequal enforcement and in the criminalisation of ordinary movement, are real. The money and attention now given to policing pedestrians would achieve more if it paid for safer crossings and lower speeds. For children the case is different, and a rule requiring them to use crossings near schools seems reasonable. But a general offence that treats every adult who crosses an empty street as a potential offender punishes the wrong people.