I believe two things about teaching:

1. The best way to learn is to do. From an article by Paul Halmos about teaching math. I began self-experimentation to learn how to do experiments.

2. Everyone’s different. My theory of human evolution says we changed in many ways to facilitate trading. (For example, language began as advertising.) The more diverse the expertise within a group, the more members of the group can benefit from trade. Following this logic, mechanisms evolved to increase diversity of expertise among people living in the same place with the same genes. (For example, a mechanism that causes procrastination.) The theory implies that there is something inside every student that pushes them toward expertise — they want to learn — but they are being pushed in many different directions — what they want to learn varies greatly. If you accommodate the latter (diversity in what students want to learn), you can take advantage of the former (an inner drive to learn).

The novelty is #2 — the idea that #2 is relevant to teaching. Human nature: People who are the same want to be different. Formal education: People who are different should be the same. At Berkeley, most professors appeared to have little idea of the diversity of their students. (At least I didn’t, until I gave assignments that revealed it.) Almost all classes treated all students in a class the same: same lectures, same assignments, same tests, same grading scheme. I heard dozens of talks about how to teach. Supporting or encouraging individuality never came up. Now and then I told other professors these ideas — at a party, for example. “Everyone’s different, but our classes treat everyone the same,” I’d say. No one agreed. It was a new and apparently distasteful idea. Too much work was one response.

I believed my theory of human evolution partly because it explained what I saw with my students (Berkeley psychology majors in undergraduate seminars): The more freedom I gave them, the more they learned. I gave them great freedom with their term project (except I forced them to do it off-campus). That worked fine. One student had an intense fear of public speaking. Her project: give a talk to a high school class. She succeeded. “What did I learn? I learned that if I have to, I can conquer my fears,” she wrote. I wrote an article about it. I taught a whole class where the students (all 10 of them) were given great freedom to do something off campus. That worked, too. But the class was too niche and the term project too small. It wasn’t obvious if the ideas would work in an ordinary class.

The more freedom I gave my students, the more difficult it became to grade them. At Tsinghua I teach a required class for freshman psychology majors called Frontiers of Psychology. There are 20-30 students. It covers recent research. For the first few years, I had students write comments on the reading. “Write something only you could write,” I said. The students struggled to figure out what that meant. I struggled to grade their answers.

Before last semester began, I had an idea: no grading. Maybe other sources of motivation, would be enough.

Last semester, my Frontiers class had two parts:

1. Reading. During this section, they read a variety of things: recent experimental papers (e.g., from Psychological Science), book excerpts (e.g., from The Man Who Would Be Queen) where I said “read any 60 pages you want”, and my long self-experimentation paper (“read any third you want”). This taught them how to do research, not just subject-matter content. A typical assignment included a class presentation. For example, each student read a different experimental paper (they chose) and gave a presentation about it. Another assignment involved an in-class debate. I discussed the readings — for example, the controversy around The Man Who Would Be Queen — and gave feedback on presentations but rarely lectured. The main lecture I gave was at the beginning to explain the course. This part of the course resembled a traditional course, except (a) no grades, no tests, (b) many class presentations (public speaking is an important skill), and (c) lots of choice in what they read.

2. Doing. This section had two parts: (a) a short (2 week) experiment where they tested the effect of whatever they wanted (chocolate, piano music, exercise, and naps of different lengths were some choices) on brain function measured by a reaction-time test written in R. They gave presentations about their results (I regret not requiring written reports). (b) a long project (4-5 weeks) where they could study whatever psychological topic they wanted. It might or might not involve data collection. The topics they chose to study included dreams, procrastination, the perception of psychologists, fujoshi, the relative femininity of different sports, the accuracy of first impressions, different ways of teaching English, comparison of Tsinghua students and Peking University students (the top two universities in China, with stereotypically different students), cognition in native versus non-native language, reading screens versus reading books, and positive psychology. They could work in groups or by themselves. They had to get my approval for what they did so that they wouldn’t try to do too much or too little. At the end they wrote a report and gave a class presentation. I met with each student or group of students individually to discuss their work, usually for 30-60 minutes. During these discussions they provided evidence (e.g., photographs, recordings) that they had done what they said.

I did give grades (I was required to) but they were minimal. The final grade was entirely based on the final project. I divided each project into parts (e.g., background research, data collection, class presentation) and gave each part a point value such that the points add up to 96 (= A). If you finish Part X, you get the associated points. (Everyone completed all parts.) If they did really well I gave them slightly more points (e.g., 97). If they failed in some serious way I gave them slightly fewer (e.g., 94). So grading was close to binary: yes or no. You could get a good grade simply by doing what you said you would do.

It was the most pleasant teaching experience of my life. It was also the easiest by far, in contrast to my Berkeley colleagues’ claim that my ideas led to “too much work.” The hours I had spent every week grading homework in previous versions of the course — the part of the course I liked least — was gone. At the end of the class, I spent many hours discussing the student projects, but I enjoyed these discussions. They didn’t feel like work. The students had chosen topics they wanted to study and seemed happy to talk about what they had done. Unlike an oral exam, almost nothing was riding on what they told me and they could be proud of what they were talking about, since it was almost entirely their idea.

The students’s work was the highest quality I have ever seen. Two of their final projects might be publishable. (And these are first-semester freshmen.) It’s not my field, so I can’t be sure, but they have great inherent interest and no obvious flaws. The students seemed to like the class, too. On the final day, which happened to be Christmas, they gave me a Christmas card signed by everyone in the class. One student gave me a card separately. “Thank you,” I said. “Why did you give me this?” Among other things, she said I had high standards. Given the absence of grades, that was interesting. Maybe it came from the fact that after every presentation, I would point out something I liked and something I thought could be better. I tried to do that with all of my feedback. Another student told me, after the final class, that what I had said about “the best way to learn is to do” was, in her case, very true. She said she had learned more in my class than in all her other classes put together.

There were about 25 students and 12 assignments = 300 (= 25 x 12) assignments total. There were about 4 instances where a student did not do an assignment. In other words, the students did the assignments 99% of the time although there was no obvious penalty for not doing an assignment. Had I given grades, I might have gotten 100% compliance rather than 99%. To use a costly (in terms of time and student anxiety) grading scheme to get a 1% improvement in compliance is absurd. Yet that may be what most professors are doing — at least, my experience suggests they could get very high compliance without expensive grading.

I think this class worked well for both my students and me because it contained several elements: 1. A “core curriculum” (recent psychological research) taught in several different ways. 2. Good-quality materials. For example, The Man Who Would Be Queen is much better than what psychology students typically read. One student told me she read the whole book even though only a third of it was assigned. 3. Plenty of doing. A class presentation counts as doing. 4. Plenty of student choice. 5. Absence of grading, which has bad side effects.

I think several things caused students to learn a lot: 1. The material was interesting. 2. To some extent — far more than in other classes — they could choose what they wanted to learn, especially during the second half of the class. 3. Peer pressure. They wanted to look good in front of their peers. It would have been embarrassing to not be able to do a presentation when called upon. 4. The instinct of workmanship. Thorstein Veblen wrote a book called The Instinct of Workmanship. People inherently want to do a good job, said Veblen. I agree. 5. Doing is fun.

Would this work with other students? My students were/are very smart, yes. Tsinghua is extremely hard to get into and entrance is mostly based on a standardized test. My students, in other words, did very well under the usual system of teaching. This can be interpreted two ways: (a) They like the usual way of teaching, it fits them (they succeeded because of the usual methods) or (b) like everyone else, they dislike the usual way of teaching but unlike everyone else figured out how to learn on their own. The first interpretation suggests that my students would benefit less than other students from the novelty of my approach. The second interpretation suggests they would benefit more. What is clear is that Tsinghua students are known for studying very hard — yet my class required no studying beyond reading and understanding.

What did I learn? I learned that I can stop grading and things get much better, not worse. I learned that motivations other than grades are plenty powerful.