AFor most of human history, finding the way from one place to another was a skill honed through constant practice. Travellers read the landscape itself — the slope of a hill, the direction of prevailing winds, the position of the sun and stars. Among the Pacific navigators of Polynesia, this knowledge reached an extraordinary level of sophistication, allowing voyagers to cross thousands of kilometres of open ocean without instruments of any kind.

BCognitive scientists describe two broad strategies the brain uses to navigate. The first, known as egocentric navigation, relies on remembering a sequence of turns relative to oneself: turn left at the bakery, continue past the church. The second, allocentric navigation, builds a mental map of how places relate to one another, independent of the traveller’s own position. The latter is more flexible but also more demanding, drawing heavily on a region of the brain called the hippocampus.

CStudies of London taxi drivers, who must memorise the city’s labyrinth of streets, found that the rear portion of their hippocampus was measurably enlarged compared with the general population. Intriguingly, the longer a driver had been working, the more pronounced the difference. This suggested that the brain’s mapping machinery, like a muscle, grows stronger with use.

DThe arrival of satellite navigation has changed the equation. When a device issues turn-by-turn instructions, the traveller no longer needs to build or maintain a mental map; egocentric directions are simply read aloud. Some researchers worry that habitual reliance on such tools may, over time, weaken our innate sense of direction, much as a calculator can erode mental arithmetic.

EYet the picture is not wholly bleak. The same technologies that risk dulling our spatial skills can also be designed to sharpen them. Experiments with navigation apps that encourage users to learn landmarks, rather than merely follow arrows, have shown that people can retain — and even improve — their mapping ability. The art of wayfinding, it seems, need not be lost so much as relearned.

AWetlands were once dismissed as wasteland — soggy ground to be drained for farms and cities. Over the twentieth century, more than half of the world’s wetlands were lost. Only recently has their value been widely recognised: they filter pollutants, buffer coastlines against storms, store vast quantities of carbon, and shelter a disproportionate share of the planet’s biodiversity.

BRestoration projects now aim to reverse the damage. The simplest approach is to remove the drainage that dried a marsh out, allowing water to return naturally. In other cases engineers must rebuild the gentle gradients and tidal channels that let water move as it once did. Success is rarely instant; a restored wetland may take a decade or more to mature into a fully functioning ecosystem.

COne celebrated example lies in the lower reaches of a major European river, where farmland was deliberately returned to the sea. Within a few years, salt-tolerant plants colonised the mudflats, fish returned to spawn, and migratory birds arrived in numbers not seen for generations. Crucially, the new marsh also absorbed storm surges that would otherwise have threatened nearby towns.

DRestoration is not without controversy. Farmers may lose productive land, and the benefits — cleaner water, flood protection, carbon storage — are spread across society rather than captured by those who give up their fields. Economists argue that without payments that reward landowners for these public goods, restoration will always struggle to compete with conventional agriculture.

AA series of experiments over the past two decades has explored a provocative question: does wealth, or even the mere idea of money, change how generously people behave? In one well-known study, participants who had been subtly reminded of money — by handling banknotes or unscrambling money-related sentences — were less likely to help a stranger who dropped a box of pencils than those in a neutral condition.

BThe researchers interpreted these findings as evidence that money primes a mindset of self-sufficiency. Reminded of wealth, people preferred to work alone, sat further from others, and were slower to ask for help. Money, the argument went, makes us feel capable of meeting our own needs, and so less inclined to lean on — or be leaned on by — those around us.

CNot everyone is convinced. Several attempts to repeat the original studies have produced weaker effects, or none at all. Critics point out that small samples and flexible analysis can manufacture striking results that evaporate under closer scrutiny. The debate has become a notable case study in psychology’s wider reckoning with the reliability of its findings.

DEven sceptics, however, accept that context matters. Whether money makes someone mean may depend less on the cash itself than on the norms surrounding it — whether wealth is framed as a private reward or a shared resource. The lesson, perhaps, is that human behaviour resists simple slogans, and that a single tidy story about money and meanness was always too good to be entirely true.