1 . Placed before you are two pots. Each contains 100 balls. You are given a clear description of the first pot’s contents, in which there are 50 red balls and 50 black balls. The economist running the experiment is tight-lipped about the second, saying only that there are 100 balls divided between red and black in some percentage. Then you are offered a choice. Pick a red ball from a pot and you will get a million dollars. Which pot would you like to pull from? Now try again, but select a black ball. Which pot this time? Most people choose the first pot both times, despite such a choice implying that there are both more and fewer red balls than in the second pot.

This fact is known as the Ellsberg paradox after Daniel Ellsberg, who called the behaviour hate uncertainty. It reveals a deeper problem facing the world as it struggles with climate change.            

Ignorance of the future carries a cost today: uncertainty makes risks uninsurable, or at the very least expensive. The less insurers know about risks, the more capital they need to protect their balance-sheets against possible losses.

Insurance is a tool of climate adaptation. Indeed, insurance calculators have as big a role to play as activists in the fight against climate change. Without insurance, those whose homes burn in a wildfire or are destroyed by a flood will lose everything. Insurance can also be a motive for corrective action. Higher insurance expenses, which accurately reflect risk, stimulate people to adapt sooner, whether by discouraging building in risky areas or encouraging people to move away from high fire risk land. If prices are wrong, society will be more hurt by a hotter world than otherwise would be the case. Politicians considering financial aid for home insurance on flood plains ought to note.

In one club in Beijing, for example, players enter into a fictional martial arts school     1     they wear costumes and assume roles like a peach fairy or a dragon. The script offers character backgrounds, relationships and potential storylines. The plot develops as the players go around the table, talking in character, taking clues from the script and the host. In the end, they vote on     2     they think the murderer might be.

The whodunits may be imaginary,     3     they provide a real-world alternative for young Chinese people who spend increasing amounts of time on their screens. The country’s one billion Internet users spend much of their time on their phones,     4     (cause) worries from the public and the government alike about too much screen time. The government’s concerns over children in particular     5     (lead) it to restrict video game time for minors recently.

The games also provide free-flowing opportunities for young people to get together, something     6     can be rare in China, according to Kecheng Fang, an assistant professor in the School of Journalism and Communication at The Chinese University of Hong Kong. The games provide “    7     participatory experience and a way of socializing, which is     8     (miss) from the life of many Chinese young people,” Dr. Fang said. They are     9     (lack) in participation in civic affairs, community     10     (engage) and meaningful socialization.

4 . Since the early to mid-2010s, social media apps have made a permanent home in many people’s phones, and spending time on social media has become as much of a daily activity as drinking water. Since so many people are on it for much of their days — especially kids, teens, and young adults — there is increased concern over what social media is doing to people.

Many argue that social media is an unhealthy way to pass the time, and that false information from online is causing confusion and panic. This type of thing happens with every generation when something new that people don’t understand comes along. So many people thought rock-and-roll was making teens morally bad, which really wasn’t the case. It is fair to say that the teenage years are hard, and that teens need an escape. Back before phones, teens would listen to rock music as a form of escapism, or they would watch TV, go to the movies, skate around, or dress up in crazy clothes. Unfortunately, all of those things at one point in time were blamed for being a bad influence on young people. Social media is the new tuck-and-roll: it’s a new thing, and people demonize (妖魔化) change.

For example, many believe that everything on social media apps is filtered (加滤镜) and that seeing perfect people and their perfectly edited lives often leads to lots of negative emotions. However, models, magazines and movies have been using retouching (修整) tools for photos and media since Photoshop and other post-production services were invented. Social media has made it easier to see more edited pictures, but social media itself isn’t making people want to look a certain way. People should acknowledge that these pictures aren’t authentic, and the posts are made to look good on purpose. Social media is hot to blame for body confidence issues when the things people want to look like aren’t even real in the first place.

It seems like most issues around social media are user errors, like anyone complaining there are too many people being addicted to social media. However, not everyone is addicted to social media; people who have any grasp on reality wouldn’t spend every waking second on the phone. It is really up to the individual how they use social media. Keeping up with the flood of posts, stories, and photos takes a lot of time — many young people admit that they spend hours on their phones every day. Yet, this seems like an easy problem to solve when the solution is simply clicking off the phone a couple hours early. So it is clear that moderation is the key to dealing with all the issues around social media.

5 . For generations, the standard way to learn how to ride a bicycle was with training wheels or a tricycle (三轮脚踏车).But in recent years, many parents have chosen to train their kids with balance bikes, pedalless (无踏板的) two-wheelers that enable children to develop the ability to control their movements well, which is not as easily acquired with an extra set of wheels. Given the benefits of balance bikes, why did it take so long for them to replace training wheels?

Leidy Klotz, an engineer at the University of Virginia, noticed that there are many similar phenomena in life, in which removing elements from existing models is uncommon. So he reached out to Gabrielle Adams, a social psychologist at the university, to try to figure out why this was the case. The two researchers thought that there might be a psychological explanation: when faced with a problem, people tend to select solutions that involve adding new elements rather than taking existing components away.

Adams, Klotz and their colleagues first carried out a set of observational studies without a control group. In one, they asked 91 participants to make a pattern symmetrical (对称的) by either adding or removing colored boxes. Only 18 people used subtraction(移除). In another, the team scanned through a collection of ideas for improvement submitted to an incoming university president and found that only 11% of 651 proposals involved removing an existing regulation, practice or program.

Next, the team conducted a series of eight experiments with over 1,500 individuals. In one experiment, people were asked to stabilize the roof of a Lego structure held up by a single block that rested atop a cube-shaped base. The reward for completing the task was $1. The researchers wrote that one group was offered a cue about potential subtractive solutions by being told, “Each piece that you add costs ten cents but removing pieces is free,” while another group was just told, “Each piece you add costs ten cents.” Almost two thirds of people in the cued group chose to remove the single block rather than adding new ones, compared with 41% of those who hadn’t received the cue.

The researchers also observed that when participants were asked to create a symmetrical pattern by adding or removing colored blocks, they tended to conduct removal more often if they were given practice trials than if they had just one chance to handle the problem. On the other hand, having to simultaneously (同时地) handle another task—like keeping track of numbers on a screen—made individuals less likely to remove elements to solve the same problem.

These findings suggest that “additive solutions tend to come to mind quickly and easily,” says Benjamin Converse, a social psychologist at the University of Virginia and a co-author of the study. “Subtractive solutions aren’t necessarily harder to consider, but they take more effort to find.”

6 . Humans, by nature, have always lived in groups and social interaction is fundamental for every part of our health. Lack of it can lead to feelings of isolation and loneliness. A strong support network and solid community bonds promote our emotional and physical health, and are critical components of a balanced adult life. However, just as with many other aspects of our lives, there seems to be a limit to how large our personal networks can grow.

Back in 1992, a British scholar named Robin Dunbar came up with a hypothetical (假设的) number defining the maximum sum of meaningful human relationships a person can have. The number, which was later named after him, was discovered accidentally while he was studying the cleaning and brushing tendencies — a social behavior —of non-human primates (灵长类动物). Around that time, researchers had discovered that the large brain of these primates was a result of their socially complex societies. The relevance was that the larger the brain, the larger the animal's social group was likely to be. Scientists could then theoretically use an animal's brain size to calculate how many members could make up this group. Dunbar applied this theory to humans, and the resulting number was roughly 150.

Dunbar's Number, however, only refers to the limit of meaningful contacts within our social network. It does not account for other relationships. Human social relationships tend to have numerous layers, and extend outward from the individual in circles with the same centre. The innermost circle contains five people: our loved ones. The next circle holds of our good friends. The third circle is reserved for people we consider friends, and the fourth is where the limit of 150 can be found. Nowadays, with various forms of electronic communication, such as websites for social networking and microblogging people find it very convenient to create online communities to share information, ideas, personal messages, and other contents. Consequently, it is possible for a human to get into the fifth (500acquainitances) circle, an impressive breakthrough that was difficult to achieve in the past.

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