Skip to content

唐逍 | Tang Syau Posts


前段时间 Slowly 上的笔友对中国文化感兴趣,但我一时不知道推荐什么资源,总觉得无论是传统文化还是流行文化都很少有现成的资源给外国人看。金庸先生去世之后我才想到,金庸的作品算是现成的资源。YouTube 上也有加英文字幕的电视剧(虽然未必是正版)。今年《射雕英雄传》的英译本 The Legend of the Condor Heroes 也出了第一卷。各大外媒也写了介绍和纪念金庸的文章,顺便在此汇总一下。

The Power of Collider

最近一直在读之前提到的 The Book of Why,我觉得 collider 的概念可能是这本书里最重要的几个概念之一。本来我也可以用自己的语言写一个介绍,但好像懒得动笔,就节选书中几段话放在这里(顺序是我刻意安排的)。

X 与 Y 相关的三种解释:

  1. X 是 Y 的原因;
  2. X 和 Y 有共同的原因;
  3. collider。

We live our lives as if the common cause principle were true. Whenever we see patterns, we look for a causal explanation. In fact, we hunger for an explanation, in terms of stable mechanisms that lie outside the data. The most satisfying kind of explanation is direct causation: X causes Y. When that fails, finding a common cause of X and Y will usually satisfy us. By comparison, colliders are too ethereal to satisfy our causal appetites.

Judea Pearl. 2018. The Book of Why. Chapter 6

什么是 collider?

ABC. This is the most fascinating junction, called a “collider.” Felix Elwert and Chris Winship have illustrated this junction using three features of Hollywood actors: TalentCelebrityBeauty. Here we are asserting that both talent and beauty contribute to an actor’s success, but beauty and talent are completely unrelated to one another in the general population.

We will now see that this collider pattern works in exactly the opposite way from chains or forks when we condition on the variable in the middle. If A and C are independent to begin with, conditioning on B will make them dependent. For example, if we look only at famous actors (in other words, we observe the variable Celebrity = 1), we will see a negative correlation between talent and beauty: finding out that a celebrity is unattractive increases our belief that he or she is talented.

This negative correlation is sometimes called collider bias or the “explain-away” effect. For simplicity, suppose that you don’t need both talent and beauty to be a celebrity; one is sufficient. Then if Celebrity A is a particularly good actor, that “explains away” his success, and he doesn’t need to be any more beautiful than the average person. On the other hand, if Celebrity B is a really bad actor, then the only way to explain his success is his good looks. So, given the outcome Celebrity = 1, talent and beauty are inversely related—even though they are not related in the population as a whole. Even in a more realistic situation, where success is a complicated function of beauty and talent, the explain-away effect will still be present. This example is admittedly somewhat apocryphal, because beauty and talent are hard to measure objectively; nevertheless, collider bias is quite real, and we will see lots of examples in this book.

Judea Pearl. 2018. The Book of Why. Chapter 3

另外两个 collider 的例子:

Try this experiment: Flip two coins simultaneously one hundred times and write down the results only when at least one of them comes up heads. Looking at your table, which will probably contain roughly seventy-five entries, you will see that the outcomes of the two simultaneous coin flips are not independent. Every time Coin 1 landed tails, Coin 2 landed heads. How is this possible? Did the coins somehow communicate with each other at light speed? Of course not. In reality you conditioned on a collider by censoring all the tails-tails outcomes.

Judea Pearl. 2018. The Book of Why. Chapter 6

The correlation we observe is, in the purest and most literal sense, an illusion. Or perhaps even a delusion: that is, an illusion we brought upon ourselves by choosing which events to include in our data set and which to ignore. It is important to realize that we are not always conscious of making this choice, and this is one reason that collider bias can so easily trap the unwary. In the two-coin experiment, the choice was conscious: I told you not to record the trials with two tails. But on plenty of occasions we aren’t aware of making the choice, or the choice is made for us.

The distorting prism of colliders is just as prevalent in everyday life. As Jordan Ellenberg asks in How Not to Be Wrong, have you ever noticed that, among the people you date, the attractive ones tend to be jerks? Instead of constructing elaborate psychosocial theories, consider a simpler explanation. Your choice of people to date depends on two factors: attractiveness and personality. You’ll take a chance on dating a mean attractive person or a nice unattractive person, and certainly a nice attractive person, but not a mean unattractive person. It’s the same as the two-coin example, when you censored tails-tails outcomes. This creates a spurious negative correlation between attractiveness and personality. The sad truth is that unattractive people are just as mean as attractive people—but you’ll never realize it, because you’ll never date somebody who is both mean and unattractive.

Judea Pearl. 2018. The Book of Why. Chapter 6

在控制变量的时候,一定不要控制 collider,因为:

[I]n a collider, ABC, exactly the opposite rules hold. The variables A and C start out independent, so that information about A tells you nothing about C. But if you control for B, then information starts flowing through the “pipe,” due to the explain-away effect.

Judea Pearl. 2018. The Book of Why. Chapter 4


第117集 说真话:不用虚假替代真实
第118集 装扮习惯:虚假生态中的文人
第119集 伪精英:空谈是他们唯一的生命方式
第120集 判断真伪文人的基本标准
第121集 面对前辈:不要把尊重变成迷思
第122集 泰斗还是「太逗」:艺术在创新中展开生命力

余秋雨 中国文化必修课


怎样将 Apple Music 设定为日语

也许这是一个比较小众的需求,我就不展开解释具体为什么要这样设定了。大体来说就是如果系统语言为英语(不管是 iOS, macOS 还是 Windows),Apple Music 日本区的很多日文曲目、中文曲目也会变成拉丁字母显示,一堆罗马音实在很难接受……但如果单纯将系统语言改为日语,Apple Music 仍然不会改变语言。

前几天我终于发现 Apple Music(其实还包括 App Store)的语言到底受什么因素影响。Apple Music 使用什么语言,取决于登录 Apple Music / iTunes Store 时的系统语言。所以如果要想更改,先要更改系统语言,然后在 iTunes Store 首页底部 Sign Out,在系统语言为日语的前提下 Sign In,Apple Music, iTunes Store 和 App Store 就会是日语的了。这时再把系统语言切回英语,也不会对 Apple Music 有任何影响,就像之前系统语言切成日语,Apple Music 仍然保持英语不变一样。但系统语言为英语时不能有再次输入密码的操作,也就是说不能购买,购买必须在日文系统下购买,否则买回来就可能是罗马字。

Windows, macOS, iOS 的操作原理都相同。

2018 年 10 月 31 日更新:已购项目的问题现在我也基本上弄明白了。

首先,对新购买的歌曲,需要在日文系统下购买,否则买回来就可能是罗马字的,还会把整个 Apple Music / iTunes Store 变回英文——相当于购买行为是重新登录了一次,登录时的系统语言会改变 Apple Music 的语言。

对于已经购买的歌曲,如果是罗马字标题希望换成日文,那么可以先在 Library 里删掉,然后在日文系统下打开 iTunes,点选菜单栏的 Account(アカウント) – View My Account…(マイアカウントを表示) 输入密码(注意这里又算登录了一次,所以必须是日文系统下输入密码),然后在页面里找到 iTunes in the Cloud 里面的 Hidden Purchases,点 Manage 之后就能把之前删掉的已购项目找回来(点选「表示する」),然后再在已购项目里重新下载就可以了。

所以一面要用英文系统,一面要用日文 Apple Music 真的是神烦。

The Science of Well-Being

好几年没有在 Coursera 上听课了。今天是偶然的机会,我在重新听「好和弦」讲流行抒情乐钢琴伴奏之后,又去这个视频里的主唱 JR 的 YouTube 频道看到他在三天前更新的视频介绍了这个耶鲁大学最受欢迎的课程The Science of Well-Being, by Laurie Santos

以下摘自《纽约时报》今年 1 月底的报道:

Students have long requested that Yale offer a course on positive psychology, according to Woo-Kyoung Ahn, director of undergraduate studies in psychology, who said she was “blown away” by Dr. Santos’s proposal for the class.

本科生心理研究主任 Woo-Kyoung Ahn 表示,长期以来,学生们一直要求耶鲁开设一门积极心理学课程。她说,桑托斯博士提出开设这门课程时,她「特别高兴」。

Administrators like Dr. Ahn expected significant enrollment for the class, but none anticipated it to be quite so large. Psychology and the Good Life, with 1,182 undergraduates currently enrolled, stands as the most popular course in Yale’s 316-year history. The previous record-holder — Psychology and the Law — was offered in 1992 and had about 1,050 students, according to Marvin Chun, the Yale College dean. Most large lectures at Yale don’t exceed 600.

安博士等管理人员预计这门课的选修人数会很多,但谁也没预料到会这么多。「心理学与美好生活」这门课目前有 1182 名本科生选修,成为耶鲁大学 316 年历史上最受欢迎的课程。耶鲁学院的院长 Marvin Chun 表示,此前的纪录保持者是 1992 年推出的「心理学和法律」课程,约有 1050 名学生选修。耶鲁的大多数大型课程的选修人数都不超过 600 人。

Yale’s Most Popular Class Ever: Happiness

Google 了一下发现这门课已经上线 Coursera(《纽约时报》今年 1 月底报道这门课的时候还只是说很快就会上线)。最近几年觉得国内上 Coursera 的网络状况真的不太好,当然我也不是随时都在测试,毕竟试过几次感觉很糟糕之后就不会太有动力去听课了。但今天的网络效果很好,不知道是不是最近用了另一家代理服务……

我自己对积极心理学(positive psychology)一直比较感兴趣,但也有好几年没有继续阅读这方面的内容了,希望这门课能带给我新的收获吧,积极心理学对个人幸福感的研究在我的哲学里是一块非常重要的基础内容。

附一封 Santos 老师的欢迎信:

Dear Learner,

Congratulations on taking part in this journey! Over the next several weeks, we’ll explore what new results in psychological science teach us about how to be happier, how to feel less stressed, and how to flourish more. We’ll then have a chance to put these scientific findings into practice by building the sorts of habits that will allow us to live a happier and more fulfilling life.

In Spring 2018, I taught “Psychology and the Good Life” for the first time. I created this Yale course because I was worried about the levels of student depression, anxiety, and stress that I was seeing as a Professor and Head of College at Yale. I originally developed this course to teach Yale students how the science of psychology can provide important hints about how to make wiser choices and how to live a life that’s happier and more fulfilling. Since I’m not an expert on positive psychology, I began by learning more about this topic, diving into the work of pioneering scientists like Martin SeligmanEd DienerBarbara FredricksonSonja LyubomirskyMihaly CsikszentmihalyiDaniel GilbertRobert Emmons, and others. I also learned more about work in social psychology and behavior change, including work by scholars such as Liz DunnMike NortonNick EpleyGabriele Oettingen, and others. The Yale course was my attempt at synthesizing work in positive psychology along with the science of behavior change. My goal was to present these scientific findings in a way that made it clear how this science could be applied in people’s daily lives.

When I first developed the class, I had no idea it would become the most popular class ever taught at Yale University. The Yale class was featured in both the national and international news media, and I was flooded with requests from people around the world to find a way to share the content of this Yale class more broadly.

This Coursera class is an attempt to do just that. My goal is to share the insights from that popular Yale class with learners far beyond Yale. To make the lectures feel more intimate, we filmed at my home in one of Yale’s residential colleges with a small group of Yale students in the audience. I hope you’ll enjoy this more personal format, which allows you to hear the sorts of questions Yale students had about the material and how they applied the science in their daily lives. We understand that many of you taking the course are not currently college students, but we hope you see yourselves as though you are part of this virtual classroom.

During this course, you’ll have the opportunity to enhance your own well-being by implementing a few simple research-based methods to your own life.

I am thrilled to share this information with a wider audience. As you go through the lessons please share your feedback with the course team! You can direct item-specific feedback via content flags and general course feedback in the Discussion Forums or in the post-course survey when you complete the course.