IELTS Academic Reading Practice Test 462

For the greater part of human history, purchases were transported home in whatever container the merchant happened to possess: a cabbage leaf, a cone twisted from yesterday's newspaper, or a cloth receptacle brought along by the customer. Paper existed, but every sheet was fabricated individually from linen and cotton rags, and the material was consequently far too expensive to be distributed without charge alongside a pound of sugar. Grocers wrapped provisions in inexpensive printed sheets, and patrons carefully preserved the wrapping, smoothed it out and employed it repeatedly.

The contemporary paper bag emerged from two separate developments: a mechanism capable of folding paper more rapidly than any pair of human hands, and a wholly new method of manufacturing the paper itself. The first was the achievement of Francis Wolle, a Pennsylvania schoolteacher with no connection whatsoever to the paper trade. In 1852 he obtained a patent for a machine that converted a continuous web of paper into envelope-shaped containers, and with his brothers he established a company to produce them commercially. Wolle's bags were secured with adhesive along three sides and lacked any base to provide volume, so they lay flat upon the counter and accommodated remarkably little.

The familiar article that shoppers would recognise today — a rectangle of paper with a square base, pleated sides and the capacity to stand open while an assistant fills it — became the subject of a bitter legal dispute. Margaret Knight, born in Maine in 1838, had entered a cotton mill as a child and had already designed a safety mechanism for its machinery when she began experimenting with bags. Working in Boston in the late 1860s, she constructed a machine that cut, folded and glued a bag with a genuine base. A certain Charles Annan, who had inspected her drawings, attempted to patent the design as his own invention; Knight produced her notebooks in court, won the case and was granted the patent.

Her machine was a miniature factory in itself. Paper was drawn from a continuous roll, cut into lengths and wrapped around a shaped block to form a tube. Blades then pressed the sides into pleats, which permitted the completed bag to be stored flat and to open into a box when filled. The base was folded over and glued, and the finished bags were counted and tied into bundles. Cutting, creasing and gluing in that identical sequence remain fundamental to industrial production.

Inexpensive paper represented the second prerequisite. Until the middle of the nineteenth century, paper was manufactured from linen and cotton rags, supplies of which were distinctly limited. In 1879 Carl Dahl, a chemist employed in Danzig, discovered a method of cooking wood chips in an alkaline solution under pressure to yield a strong brown pulp. The technique acquired the designation kraft, from the German term for strength, and it transformed the economics of everything fabricated from paper. Dahl was not contemplating shopping: his objective was to convert forests into paper cheaply, yet the material he produced proved sufficiently durable to carry weight.

By the 1880s American cities were expanding rapidly, and shopkeepers required bags that could be opened with a single movement. In 1883 Charles Stillwell of Philadelphia patented a machine that manufactured a pleated bag with a square bottom from kraft paper, commonly described as the self-opening sack. The exterior could be printed with the establishment's name, the bags were sold in bundles, and for the following century groceries left the store in precisely this form. Twisted paper handles were introduced early in the twentieth century, so that a loaded bag could be carried on foot or upon a tram.

For several decades the paper bag encountered no serious competitor. That situation altered during the 1960s, when a Swedish engineer, Sten Gustaf Thulin, designed a one-piece carrier manufactured from polyethylene for a company named Celloplast, and the plastic bag proliferated through supermarkets on both sides of the Atlantic. It was lighter, impervious to water and considerably cheaper to transport, and within two decades it had supplanted paper in many large stores. Charges upon single-use bags, introduced in numerous countries, have subsequently returned some shoppers to paper and many more to reusable cotton.

The environmental comparison is less straightforward than it appears. A paper bag is heavier than a plastic one and demands more energy and water during production; life-cycle studies have generally concluded that a paper bag must be employed several times before its impact falls below that of a thin plastic carrier. Conversely, paper is recycled easily in most municipal systems, it can break down quickly if it is buried or left in the open, and it can be manufactured from managed forests rather than from fossil fuels.

Paper bags have additionally acquired a cultural existence that plastic never possessed. Bookshops have them printed with care; a brown paper bag is a familiar property on stage and screen; and the restoration of paper in certain cities has been welcomed as a small piece of good manners. Manufacturing, meanwhile, has continued to develop. Contemporary machines print, fold, glue and count bags at velocities that would have astonished Knight's contemporaries, and accomplish this without a hand touching the paper.

The paper bag, therefore, is a modest object with an immodest history: a schoolteacher's patent, a mill worker's lawsuit, a chemist's cooking process and a considerable quantity of mechanical ingenuity, folded into something that costs a few pence and is usually discarded without a second thought.

Few changes in family life are as reliable as the one that arrives at about the age of thirteen. A child who once bounced out of bed at half past six becomes, for a few years, incapable of rising before nine, and is wide awake at midnight. Parents interpret this as laziness or defiance, and a certain amount of both may be involved. But the change also has a biological basis that researchers have measured with some precision. In most families the pattern lasts until the late teens or early twenties, when sleep begins to drift earlier again.

Sleep is governed by two systems. The first is a circadian clock in the brain, a cluster of cells in the hypothalamus that sets the timing of almost everything in the body, from temperature to the release of hormones. Left alone, this clock runs slightly long, at a little over twenty-four hours, and it is corrected every day by light. Cells in the retina report the level of brightness to the clock, which uses that information to decide when the pineal gland should release melatonin, the hormone that makes us feel sleepy. Body temperature falls before sleep and rises before waking, and alertness follows the same curve. Melatonin is not a sleeping drug; it is a signal, and the body responds to it slowly.

During puberty, the clock shifts. In laboratory studies, children and adolescents are asked to stay in dim light so that the timing of their melatonin can be measured without interference, and the results are consistent: after the physical changes of puberty begin, melatonin is released later in the evening, by an hour or two. A second change works in the same direction. Sleep pressure — the desire to sleep that builds up the longer a person stays awake — accumulates more slowly in adolescents, so a teenager can stay up later without feeling tired. Sleep pressure is chemical as well as behavioural: a substance called adenosine accumulates in the brain during waking and is broken down during sleep.

Biology is only half of the story. Teenagers also have more homework, more part-time work and more reasons to be in touch with friends at eleven at night. Screens are often blamed, and screens do keep people up: light from a phone in a dark room tells the clock that it is still daytime. Yet the delay in sleeping appears even in families where screens are restricted, so it cannot be explained by technology alone.

The consequences are not trivial. National surveys in the United States have repeatedly found that more than two thirds of secondary-school students sleep less than the eight to ten hours that specialists recommend for their age. Insufficient sleep in adolescence is associated with poorer concentration in class, lower mood, irritability and a higher risk of accidental injury; it is also associated with symptoms of anxiety and depression, although whether it causes them, or results from them, is disputed. Since teenage drivers are inexperienced, drowsiness adds a particular danger. Teachers notice it too: the pupil who cannot stay awake in a morning lesson is often the one who was awake at two.

The weekend brings a temporary solution and a further problem. Teenagers who have slept badly all week tend to sleep until midday on Saturday, and they feel better for it. But the body takes its cues from the timing of sleep as well as from light, and a late weekend reinforces the later rhythm. The result is a kind of internal time difference, which researchers call social jetlag; the clock has, in effect, travelled west for two days and must fly back on Monday. By Sunday night the teenager is not sleepy, and Monday morning begins another week of debt.

The most direct remedy is to move the school day. In 2014 the American Academy of Pediatrics reviewed the evidence and recommended that secondary schools start no earlier than half past eight. Some districts have done so, and studies of the change have generally reported modest gains: students sleep longer, attendance improves and there are fewer reports of lateness. A study of two high schools in Seattle that moved their start time almost an hour later found that students gained around half an hour of sleep a night, and their grades improved slightly. Buses are shared between schools, sports fixtures and parents' working hours depend on the existing timetable, and some families argue that a later finish leaves less time for after-school jobs.

Other questions remain open. It is not settled whether the shift in timing is a cause of adolescent brain development, a consequence of it, or simply one of its features, and the long-term effects of a later school day on learning have not been tracked for long. Melatonin tablets are widely sold and widely used by parents, but they are not designed for children, their contents vary, and evidence about their long-term safety is limited. What can be offered is advice. Daylight in the morning is the most useful signal available. In the evening, lights should be turned down and screens switched off. Going to bed and getting up at regular times, at weekends as well as on school days, prevents the clock from drifting. A short nap in the early afternoon is better than a long one after dinner.

Most democracies fix eighteen as the age at which citizens may vote. A minority have gone further. Austria lowered the age for national elections in 2007, becoming the first member state of the European Union to do so; Scotland allowed sixteen- and seventeen-year-olds to vote in the 2014 independence referendum and has kept the rule for its own parliament; Malta and Wales have since extended the franchise for some elections; and several Latin American countries permit the youngest citizens to vote, though not always as a duty. The question, in other words, is no longer hypothetical.

The case for change begins with the responsibilities of adult life. A sixteen-year-old may leave school, work full time and pay income tax; in some jurisdictions may be prosecuted in an adult court; and in some countries may marry with permission. Yet the decisions that will shape that person's life longest — on climate, on public debt, on the pensions that will be paid, or not paid, in fifty years — are taken by an electorate that excludes them. If representation is supposed to accompany taxation, why is the tax collected and the vote withheld? The argument has an old pedigree; it echoes the complaint of the American colonists.

A second argument rests on habit. Studies of electoral behaviour in several countries have found that voting is a habit formed early: a person who votes in the first election for which they are eligible is considerably more likely to vote in the next, and the pattern persists over decades. Those who miss that first opportunity are harder to bring back. On this view the age at which people are enfranchised is not merely a question of fairness; it is a lever that shapes the health of democracy for a generation.

The evidence from places that have made the change is mixed but informative. Analysts who studied the Scottish independence referendum reported that turnout among sixteen- and seventeen-year-olds was higher than among voters in their early twenties. Austrian studies have found the youngest electors turning out at rates broadly comparable with slightly older groups. Researchers who compare election results across countries, however, point out that no consistent pattern has emerged: in some contests the youngest group has voted in healthy numbers, in others in noticeably fewer, and the circumstances of a one-off referendum are not those of an ordinary election.

Opponents of the change make three replies. The first is developmental: the prefrontal regions of the brain, which support planning and the restraint of impulse, continue to mature well into the twenties, and it is argued that a decision as weighty as a vote should require settled judgement. The second is consistency: at sixteen a person cannot buy alcohol, sign a contract, sit on a jury or stand for parliament, so the vote would be an anomaly. Critics who take this line argue that the franchise should be withheld until the other marks of adulthood have been acquired. The third concerns influence: many sixteen-year-olds, it is said, would vote as their parents do, or as their teachers urge.

Each reply can be answered. If maturity were the test, it is not clear that the present electorate would survive it: adults are influenced by advertising, by newspapers and by friends, and nobody proposes to take their votes away. The inconsistency is real but cuts both ways, since the ages at which different rights are acquired have never been uniform; they are a series of historical compromises rather than the application of a principle. As for parental influence, the evidence is thin, and in any case a vote cast by an adult under the influence of a newspaper is not usually thought to be invalid.

The most serious objection concerns turnout. If the youngest electors vote less often than the rest, lowering the age could depress average participation and leave young people, in practice, with less influence rather than more. The effect is likely to be modest, since sixteen- and seventeen-year-olds are a small fraction of any electorate. Whether it is outweighed by the habit-forming benefit depends on how long the habit lasts and on whether the first opportunity is made easy, which brings electoral administration into the argument.

Electoral administrators point out that extending the franchise means adding a new group to the register, and that sixteen-year-olds change address more often than settled adults and are therefore harder to trace. Schools can help, since almost the whole group is in one place, but registering pupils raises questions about consent and privacy. Administrators also warn that budgets for registration and for polling-day staff are already stretched. These are practical difficulties rather than objections of principle, but a reform that ignored them would disappoint the people it was meant to serve.

Would the change improve democracy? Not by itself. Lowering the age without teaching civics would add names to the register without adding understanding, and schools have an obvious part to play in preparing pupils for their first vote. My own view is that the case for sixteen is sound, but that it rests on two arguments rather than on the claim that sixteen-year-olds are as wise as forty-year-olds. The young have the longest stake in the future, and the habit of voting is best acquired when it is first offered. A single referendum, held in exceptional circumstances, is a fragile basis for prediction, but the risk of extending the franchise seems to me smaller than the cost of leaving a generation outside it.