1 . A middle-aged woman playing by herself in the snow is an undeniably odd sight, but maybe it shouldn’t be. New research suggests that modern adults are suffering from overmuch depression, so play may be as essential to our health as sleep. We’ve been in our nature to play, which is causing all kinds of problems—for ourselves, our children, and our planet.

It’s believed that adult play can lead to useful discoveries, which is supported by a study on Bali’s long-tailed monkeys. For her doctoral paper at the University of Lethbridge, animal researcher Camilla Cenni left two types of puzzle boxes for the monkeys to solve. To get the food inside, they had to drop a rock into the container or use it to hit the box. She found the monkeys that previously had been observed dropping rocks for fun were more likely to solve the rock-dropping puzzle, while those that had discovered the joy of tapping rocks together think of the answer to the tapping puzzle.

This finding also suggests that somewhere, deep in our evolutionary history, a playful proto-human(原始人) came up with the concept of stone tools. Even today, the urge to play underlies most of humanity’s greatest inventions, artworks, and scientific breakthroughs, Brown says. “When I interviewed Nobel winners, I was struck by how most of them didn’t separate work and play. Their labs were their playgrounds”.

“The opposite of play isn’t work; it’s depression,” says play researcher Stuart Brown, “Play is all about looking at a tough world with creativity and optimism. It gives us the ability to cooperate and get along with people who differ from us,” He goes so far as to declare that “adult play is necessary for our survival as a species.”

The next time I’m caught playing, I know exactly what I’ll say: “I am not wasting time, or acting immature. I’m doing nothing for the benefit of all humanity. You’re welcome.”

3 . Most of us are familiar with the concept of six degrees of separation — the idea is that anyone in the planet can be connected to anyone else in just six steps. But is there actually any science to back up this commonly cited theory?

If you just take a look at the following numbers, the six degrees of separation idea seems pretty plausible. Assuming everyone knows at least 44 people, and that each of those people knows an entirely new 44 people, and so on, the math shows that in just six steps everyone could be connected to 44⁶, or 7.26 billion people — more than are alive on Earth today.

But this idea wasn’t scientifically tested until the 1960s, when a psychologist sent 300 packages out to people in Nebraska and Boston, and asked them to use their networks to get them back to one specific target — a stockbroker (股票经纪人) living in Boston. They weren’t asked to forward it to him directly, but to send it to someone they knew on a first name basis, with instructions for that person to forward it on to someone in their network that they thought might know the stockbroker.

Only 64 of those packages actually reached the target, with an average path length of just 5.2 intermediary (中间人) connections, and this experiment was used as evidence for six degrees of separation, or the “small world phenomenon”, as the researcher called it.

But Derek Muller, a researcher, dug a little deeper, and found that, of the original 300 packages, 100 were sent to people already living in Boston (where the target also lives) and 100 were sent to stockbrokers who shared a profession with the target, so there were really only 100 purely random packages sent out. And of those 100, only 18 made it back to the target. “So we’re talking about a sample size of 18 — that’s all the evidence there was for six degrees of separation,” Derek explains.

Care for the Disabled

Two vegetarian meals each day. A monthly budget of 200 yuan. Working just one or two months a year. In April, an Internet     1    (use) posted this brief description of his simple, stress-free life. He described his philosophy     2    tangping. “I can be like Diogenes, who slept in his wine cask (桶) in the sun,” he wrote.

The post spread     3    (crazy). On social media, people showed their approval of tangping by sharing pictures of themselves (and, often, their cats)     4    (lie) in bed. More than 60％ of over 240, 000 respondents to a poll (民意测评) on Weibo, said tangping was their idea of the good life.

Tangping     5    (describe) a longing to escape the pressure of modern life in China, where young people    6    (expect) to work long hours, buy property, get married and have children. Many people in their 20s and 30s grumble (抱怨) that hard work no longer rewards them with a     7    (good) quality of life. They have adopted an academic term, neijuan or “involution”, to describe how extra input no longer produces more output.

    8    academic from Tsinghua University thought of tangping to be “ extremely irresponsible”. “The only way     9    (ensure) a happy life is working hard,” said a commentary in one newspaper, “this attitude disappoints one's parents     10    hundreds of millions of taxpayers as well”.

7 . Decision hard

From the moment we wake up each day, we’re faced with a continuous stream of choices.    1    , when there are too many options. This is decision fatigue (疲劳), a state of mental overload that can impede (妨碍) our ability to make additional decisions.

When decision fatigue kicks in, you may feel like you just don’t have the mental bandwidth to deal with more decisions.     2    . As a result, you avoid making certain choices entirely, go with the default option or make ones that aren’t in line with your goals or values, experts say.

Here’s how to minimize or manage this phenomenon:

    3    . Some easy ways to do this: When you go grocery shopping, use a master list that has the same staples, and buy the same brands each time.    4    . And if you’re trying to exercise regularly, devote a consistent amount of time for it every day.

Tune into how you’re feeling. Be watchful of signs of decision fatigue and act accordingly: If you’ve had a demanding day that was filled with lots of decisions, put off making another one if you can. If things that wouldn’t normally upset you start bothering you, consider that a sign that you may not be in the best state of mind to make a major decision. “People may not realize that they’re experiencing decision fatigue,” Baumeister, a professor of psychology at the University of Queensland in Australia, says. “    5    .”