Yanwen’s blog

9/16/2026

Earlier this month, I wrote a piece about the seasonal memories associated with going back to school. For a long time, perhaps dating back to my own elementary school years, I have had a special fondness for summer—the lazy summer days of catching dragonflies, playing outdoors, and simply doing nothing in particular.

Autumn, on the other hand, has always made me feel a little down. Perhaps it is the sight of leaves falling and nature preparing for winter dormancy in late autumn and early winter. For a long time, I thought I was simply one of those people who felt this way. Later, I learned that there is a medical term for a recurring seasonal change in mood: Seasonal Affective Disorder (SAD). Some people even use medication to help manage its symptoms.

When it comes to regulating our emotions, many non-medication approaches involve changing our thoughts, reframing how we see things, and learning to accept our emotions.

This reminds me of David Phillips's book High on Life: How to Naturally Harness the Power of Six Hormones and Revolutionize Yourself.

Phillips discusses six chemicals closely related to our emotions, motivation, and mood: dopamine (多巴胺), testosterone (睾酮), endorphins (内啡肽), oxytocin (催产素), serotonin (血清素), and cortisol (皮质醇).

Dopamine (多巴胺) is closely associated with motivation, focus, and reward-seeking behavior. When the dopamine system is activated, we may feel, “I want to do it.” The important word here is want.

One important function of the dopamine system is its role in reward prediction—our brain responds not only to a reward itself but also to the anticipation that a reward is coming.

Think about our to-do lists. There are many things we know we should do, but don't really want to do. So how can we turn “I should” into “I want”?

Phillips suggests giving the brain something to look forward to. Instead of focusing only on the final reward, we can create small expectations and positive feedback along the way.

For example, if you want to go running, choose a route you really enjoy in advance and your favorite songs. Perhaps you can look forward to the scenery, listen to your favorite music, or plan to stop somewhere you like afterward.

In other words, plant a few small hooks in the future.

Maybe motivation is not always something we have to wait for. Sometimes, we can create a reason for our brain to look forward to what comes next.

More on these chemicals tomorrow...

9/15/2026

Yesterday I wrote about “搭子” (dāzi). From sociological perspective, this reveals some competing desires:

1. The human need for connection — people don't want to be completely alone. They want someone to eat with, exercise with, travel with, talk with, or share an interest with.

2. The desire for autonomy and freedom — they want freedom from the obligations, expectations, emotional demands, and potential conflicts that come with a long-term relationship, and desire for diversity in their social life. 

“Dazi” allows people to have different people for different experiences rather than expecting one friend—or one partner—to meet all their social needs.

No single lightweight relationship has to become boring, demanding, or all-consuming.

At this point I think of the young relative of mine who broke up with his girlfriend last year. Perhaps 12 years together had created a familiarity which can be boring and causing him to seek novelty outside the relationship.

We don’t know whether this preference for lightweight socializing is simply a response to modern life—or reflects a broader change in how people think about relationships.

Whatever the explanation that we may have, I think there is a cost for chasing freedom, variety and novelty. We may be losing something that can only be created through staying with the same person for a long time.

Finally, Dazi may offer freedom from the burdens of traditional relationships, but some of the things we value most in human relationships—trust, intimacy, loyalty, and being truly known—are built precisely through those burdens and will last longer than this modern trend.

9/14/2026

I heard of this term on Chinese internet: “搭子” (dāzi) and, more specifically, “搭子社交”, “轻量化社交”, and “模块化社交.” Lightweight social activities.

What is “搭子”?

A 搭子 is essentially someone you do a particular activity with:

• 饭搭子 — someone to eat with

• 运动搭子 — exercise partner

• 骑行搭子 — cycling partner

• 旅游搭子 — travel companion

• 游戏搭子 — gaming partner

• 追剧搭子 — someone to watch shows with

• 学习搭子 — study partner

The key part is that you don't necessarily want this person to become a close friend. You just want to do certain activities with that person.

“搭子” is a relationship built around shared interests, while noting that young people are simultaneously trying to avoid the burdens and commitments associated with traditional social relationships.

Traditional friendship tends to be holistic.

A friend might know your family, your work, your problems, your childhood, your personality, and even your secrets.

But a “搭子” relationship can be functional:

I like cycling.
You like cycling.
We cycle together.
We don't necessarily need to know much about each other's lives.

One Chinese report gives an extreme example: some cycling partners have gone a whole year without even exchanging their real names.

And there is an even more extreme version: “zero-sugar socializing” —“降糖社交” (reducing the “sugar” in social relationships), also called “低糖社交” or “零糖社交.”

The “sugar” metaphor refers to the emotional sweetness—and burden—of close relationships.

The research actually suggests that young people still want deep relationships. The difference is that they don't necessarily expect one person to fulfill every social need.

The question is 

Are young people redefining friendship—or are they trying to get the benefits of companionship without the responsibilities that traditionally came with friendship?

Interesting question! I will get back to this tomorrow.

9/13/2026

Happy Birthday!

Yesterday, someone shared with me the 2024 Lancet Commission report, “Dementia Prevention, Intervention, and Care.”

The report updates the Commission's earlier work from 2017 and 2020 and identifies 14 potentially modifiable risk factors for dementia across the life course.

The headline finding is striking: the Commission estimates that addressing these 14 risk factors could potentially prevent or delay nearly 45% of dementia cases worldwide.

The 14 risk factors include:

Environment

• Air pollution

Health-related

• Untreated vision loss

• Hearing loss

• Depression

• Traumatic brain injury

• High LDL cholesterol

• Diabetes

• Hypertension

• Obesity

Lifestyle-related

• Physical inactivity

• Smoking

• Excessive alcohol consumption

Social and educational

• Less education in early life

• Social isolation

Of course, dementia has many causes, including genetic and other factors that individuals cannot control. The 45% figure is a population-level estimate of potentially modifiable risk, not a guarantee that an individual can prevent dementia by changing these factors.

Some risk factors, such as age and family history, are largely beyond our control. But many others can be influenced, at least to some degree, through medical care, lifestyle, environment, education, and social connection.

What strikes me most about the report is its life-course perspective.

The way we age is not determined only by what we do after we become old. It is influenced by things we do—and things that happen to us—many years, even decades, earlier in life.

That means dementia prevention begins much earlier.

Perhaps the lesson is asking a simpler question:

What can I do today that might help me remain healthier tomorrow?

Stay physically active. Keep learning. Protect our hearing and vision. Don't smoke. Manage blood pressure and cholesterol. Maintain social connections. Wear a helmet when appropriate. Get medical problems treated rather than ignored.

None of these things comes with a guarantee.

But perhaps healthy aging means making good choices, year after year, to give ourselves the best possible chance of a healthy future. So that we have more influence over that journey than we sometimes realize.

9/12/2026

Around China's Teachers' Day, I came across an interesting piece of news from New York City, where I live.

Starting this school year, New York City Public Schools is placing a one-year moratorium on student-facing generative AI for students from 2-K through eighth grade. At the same time, the city is putting limits on individual screen time for younger students.

The policy takes a different approach with high school students. The city will require AI-literacy instruction and allow limited, supervised use of several approved AI programs. Every high school student will receive two 45-minute AI-literacy modules covering topics such as how AI works, bias, privacy, risks, and appropriate use.

Teachers can still use approved AI tools for lesson planning and operational tasks, but AI cannot be used for grading, behavior monitoring, or decisions about students' placement, promotion, or graduation.

The policy also prohibits AI companion chatbots across all grades and limits individual screen use for younger students. Students in grades 2-K through second grade will have no one-to-one screen time, while the city recommends no more than 30 minutes a day for grades 3–5 and 45 minutes for grades 6–8. There are exceptions for assistive technology and other necessary uses.

This made me think about a much more fundamental question:

What do children actually need from school?

If AI can answer almost any question a child asks, why do children still need teachers?

Because education is not simply the transfer of information.

A child can ask ChatGPT to explain fractions. AI may provide an accurate explanation in seconds. But an elementary-school teacher can notice that the child is frustrated. The teacher can encourage the child to try again, discover exactly where the confusion lies, adjust the explanation, and perhaps teach the child something that has nothing to do with fractions:

Don't give up just because you don't understand something yet.

AI can answer questions. A teacher can help a child become someone who knows how to find an answer, how to keep trying when the answer doesn't come easily, and how to learn from mistakes.

That distinction matters particularly for young children.

At the elementary-school age, children are still developing their confidence, curiosity, habits, and attitudes toward learning. They are learning not only what to know, but also how to think, how to ask questions, how to work with others, and how to deal with difficulty and frustration.

This is why people have always thought elementary-school teachers have a particularly important role. They are helping children form their first ideas about themselves as learners:

Am I good at learning? Is it safe to ask questions? What happens when I make a mistake? Can I solve something difficult? Do I give up when I don't know the answer?

The NYC policy explicitly puts some of these ideas at the center of its approach. For younger students, the schools say learning should emphasize human interaction, play, discussion, creativity, and the opportunity to work through difficult problems themselves rather than simply outsourcing those problems to a machine.

I find that particularly interesting.

AI may become one of the most powerful tools children will ever have. Before giving children powerful tools, we should make sure they have developed the ability to think for themselves.

They need to experience the frustration of not knowing the answer.

They need to struggle with a difficult problem instead of immediately asking a machine to solve it.

They need to learn how to work with another person, listen to a different point of view, make mistakes, and try again.

And they need to experience something AI cannot provide: a human being who knows them, notices them, encourages them, and believes in them.

The more important question is:

What should children learn to do for themselves before AI starts doing it for them?