Practice Test 25: Finding Our Way and Charging for Plastic Bags

A For most of history, finding the way meant building a mental map. Travellers noted landmarks, learned the shape of a coastline or recalled turns on a road, and the effort of doing so strengthened their sense of place. Today many people follow a voice from a phone instead, and researchers have begun to ask what is lost.

B Neuroscientists have studied a brain region called the hippocampus, which is involved in memory and navigation. Studies of London taxi drivers, who must learn thousands of streets, found that this region was larger in experienced drivers than in the general public. This suggests that navigating by memory exercises the brain, although it does not prove that the drivers began with different brains.

C Several experiments have compared people who follow turn by turn directions with those who use a paper map. The map users tended to remember the layout of the area better, while the satellite navigation users often arrived accurately but could not sketch the route afterwards. A likely explanation is that following instructions requires little thought about the surroundings, so little is stored.

D None of this means that navigation apps should be abandoned. They save time, improve safety and help people with a poor sense of direction. Researchers suggest a middle path: using the app when speed matters, and sometimes studying the map first, or turning the app off on familiar routes, so that the mind stays engaged with the places we move through.

A When a number of countries introduced small charges on plastic bags, many observers expected little change. The fee was usually tiny compared with the cost of the shopping, and bags had been free for decades. Yet in country after country, use of bags fell sharply within months. The result surprised economists who assumed that only a high price could change habits.

B Behavioural economists offer an explanation. Free items are treated differently from items with any price at all, however small, because even a small charge makes a person stop and decide. The charge also acts as a signal: it tells shoppers that the bag is not costless to society, and that a change in behaviour is expected. Many people respond by bringing their own bag, which then becomes a new habit.

C Design matters. Charges worked best where they were simple, applied to all shops, and explained clearly. Where the rules had many exemptions, people found it harder to understand the policy and the effect was smaller. In some places, retailers switched to thicker reusable plastic bags that were sold cheaply, and the total weight of plastic did not fall as much as hoped.

D The policy shows how modest nudges can change behaviour, but also its limits. A charge on bags does not address larger sources of plastic waste such as packaging, and it may change shoppers' sense of having done enough. Policymakers therefore treat it as a starting point and not as a complete solution.