IELTS Academic Reading — Practice Test 24

For much of the last century, town planners treated parks and gardens as pleasant extras — ornaments to be added once the serious business of housing, roads and drains had been settled. That view is now being quietly overturned. A growing body of research suggests that the trees, lawns and waterways threaded through a city are not decoration but a form of public health infrastructure, as consequential for the wellbeing of residents as clean water or safe streets. As the share of humanity living in cities climbs past its historic peak, the question of how much green space urban dwellers can reach, and of what kind, has moved from the margins of planning to its centre.

The evidence for physical benefits is the least controversial. Public-health researchers who track large populations have repeatedly found that people living within easy walking distance of parks tend to be more physically active, and show lower rates of heart disease and obesity, than those without such access. Green space also cools its surroundings: on a hot afternoon a well-planted park can be several degrees cooler than the concrete streets around it, easing the heat that kills thousands of city dwellers each summer. Trees filter some airborne pollutants and dampen traffic noise. Taken together, these effects help explain why proximity to greenery is associated, in study after study, with longer life expectancy.

Harder to measure, but increasingly well documented, are the effects on the mind. One influential idea, known as attention restoration theory, holds that the effortless, gentle stimulation of a natural setting allows the brain's capacity for focused concentration — worn down by the relentless demands of urban life — to recover. Experiments lend it support: people asked to walk in a park afterwards perform better on tests of attention and memory than those who walk the same distance along a busy street. Time among greenery also appears to interrupt rumination, the repetitive dwelling on negative thoughts that accompanies anxiety and depression, and even a view of trees from a hospital window has been linked to faster recovery after surgery.

Precisely why nature should have these effects, however, remains disputed. Some critics caution that the benefits attributed to green space may owe less to nature itself than to the things it encourages. People in leafy neighbourhoods walk and cycle more, meet their neighbours more often, and breathe cleaner air; disentangle these from the mere presence of grass and trees, the sceptics argue, and the special power of nature may shrink. Others counter that carefully controlled experiments, in which the only variable is the setting, still show an effect, pointing to something restorative in natural surroundings that exercise and company alone cannot explain. The debate is far from settled, and it matters, because the answer shapes what cities should actually build.

Whatever the mechanism, green space is not shared out equally. In most cities, wealthier residents live closer to larger, better-maintained parks, while poorer districts — where the health benefits might do the most good — are often the most starved of greenery. Efforts to correct this can backfire in an unexpected way. When a neglected neighbourhood gains an attractive new park, property prices frequently rise, and the very residents the improvement was meant to help may be priced out and displaced. Researchers have given this paradox a name: green gentrification. It has made some planners wary, and has prompted calls to pair new parks with measures that protect existing residents from being pushed out.

It is also becoming clear that not all green space is equally good for us. A sterile lawn mown to a uniform carpet delivers far less, on almost every measure, than a richly planted space full of varied trees, shrubs and flowers, which supports more wildlife and offers the mind more to absorb. Size, safety and ease of access matter too: a large park that feels dangerous, or that residents cannot reach without crossing a motorway, will sit unused. The lesson planners are drawing is that quantity is not enough. A city does not become healthier simply by adding hectares of grass; it must add the right kind of space, in the right places, within reach of the people who need it most.

None of these complications weakens the central case. The most persuasive advocates argue that green space deserves to be planned, funded and protected with the same seriousness as any other essential service, rather than being the first thing sacrificed when budgets tighten. Cities will always face competing demands for scarce land, and parks will always be tempting to build on. But to treat a park as a luxury, in the light of what we now know, is to misunderstand what it does. The greenery of a city, on this view, is not the reward for a healthy population but one of the conditions that makes it possible.

Laughter is one of the first things we do and one of the last we understand. Babies laugh months before they can speak, people in every known society laugh, and even those born deaf and blind, who could never have learned it by imitation, laugh all the same. It is, on the face of it, a strange response: a sudden, rhythmic convulsion of breath, serving no obvious practical purpose, provoked by things as varied as a pun, a pratfall or a tickle. For more than two thousand years, philosophers and, more recently, psychologists have tried to say what, if anything, these occasions have in common. Their answers fall into a handful of broad families, each capturing part of the truth and none, so far, the whole of it.

The oldest explanation is the least flattering. Plato and Aristotle both regarded laughter with suspicion, as a form of derision aimed at people who are in some way inferior or ridiculous. The idea was sharpened in the seventeenth century by Thomas Hobbes, who described laughter as a 'sudden glory' arising from the sense of our own superiority over others — over their blunders, their ignorance, or our own former selves. There is clearly something in this. Much of what people find funny does involve someone coming off badly, and the cruelty of a good deal of comedy is hard to deny. Yet superiority cannot be the whole story, for we laugh happily at clever wordplay and absurd situations in which no one is belittled at all.

A second family of theories shifts attention from the target of laughter to the state of the person laughing. In the nineteenth century Herbert Spencer, and later Sigmund Freud, proposed that laughter serves to discharge nervous energy that would otherwise have no outlet. On this account we build up psychological tension — around forbidden subjects, say, or in a moment of fear — and laughter is the safety valve through which that pressure escapes. It would explain why humour so often circles taboo topics, and why people sometimes dissolve into giggles at funerals or after a narrow escape. Critics object that the underlying physiology was always vague, and that the theory struggles to explain the many occasions when we laugh with no evident tension to release.

The account most widely favoured today locates humour not in the laugher or the target but in the structure of what is perceived. According to incongruity theory, we are amused when our expectations are set up and then violated — when a sentence, a scene or an image swerves suddenly from the path our minds had laid out for it. The classic joke does exactly this: a story leads us to assume one interpretation, and the punchline abruptly forces another. The theory captures something real about the mechanics of a joke, but it cannot be complete on its own. A great many incongruities are not funny at all; a jarring mistake or a frightening surprise also violates expectation, yet provokes confusion or alarm rather than laughter. Incongruity, it seems, is necessary but not sufficient.

Recent researchers have tried to specify what must be added. One prominent proposal, the benign violation theory, holds that we laugh when something is wrong — a norm is broken, a threat appears, an expectation is dashed — and yet the situation is simultaneously felt to be safe, acceptable or of no real consequence. A joke that strikes an audience as genuinely threatening or offensive fails, because the violation is not benign; one that is entirely harmless and predictable falls flat, because there is no violation at all. Humour, on this view, lives in a narrow zone between the two, which is why timing, tone and context matter so much, and why the same remark can convulse one room and appal another. It also neatly explains why we can laugh at our own past misfortunes once they are safely behind us.

All these theories share an assumption that laughter is essentially a response to something funny. A strand of research has turned that assumption on its head. The psychologist Robert Provine, who recorded thousands of everyday laughs, found that most occurred not after jokes but after utterly banal remarks — 'I'll see you later', 'Are you sure?' — exchanged between people who were simply enjoying one another's company. Laughter, he concluded, is far more a social signal than a reaction to wit: a largely involuntary display that binds groups together, smooths conversation and reassures others that all is well. Its notorious contagiousness supports the point; we laugh far more readily in company than alone. If this is right, then jokes may be a comparatively late refinement of a much older instrument for holding a group together.

Whatever laughter is for, appreciating a joke turns out to make surprising demands on the mind. To find a pun funny is to hold two meanings of a word in view at once; to enjoy a twist is to build one interpretation, notice it fail, and rapidly construct another; and much humour requires us to track what another person believes, expects or fails to realise — the same capacity to model other minds that underlies deception and storytelling. Some scientists take this as evidence that sophisticated humour is distinctively human. Others are more cautious, noting that rats chirp when tickled and that young apes produce a panting, laughter-like sound during rough play, which hints that the raw material is far older than our species. Whether the human joke is a difference of degree or of kind remains, fittingly, an open question.