I want to talk about the qualities a graduate student should have. Let me start with what does not matter much: the least important quality is your IQ.
No matter what field you are in—physics, engineering, biology, literature—I believe IQ is the least important factor. I really mean that.
So what is important?
1. Time and effort
Do not imagine you can get by with a bit of cleverness. There is no free lunch in this world. That has always been true. Because of that, I am often annoyed when people say, “My success was entirely due to luck.” I think that is nonsense. I do not believe any successful scientist has ever done it without enormous effort.
Take a professor from Tsinghua University’s Department of Biology, known in the United States as a well-respected endowed chair professor. When he taught students in the U.S., he would say something like this:
In my academic career, my biggest secret has been hard work. I work more than 60 hours a week. I know you may not work as hard as I do, but I still expect you to work at least 50 hours a week. That means if you work eight hours a day, you need to work more than six days a week. Do not think that if you show up at 8 a.m., do a little bit of lab work in a daze, and leave at 8 p.m., that counts. It only counts the actual time you spend doing experiments and the time you truly spend reading papers related to those experiments. Meals do not count, and the hour you relax after reading papers does not count either. So 50 hours a week is already a very heavy workload. If you can meet that standard, you can stay in my lab. If you cannot, then leave.
That was not empty talk. It was the plain truth, spoken by a scientist with real integrity. The point of that example is simple: if you do not invest time, you will not succeed.
2. A change in methodology
The second important thing is a change in how you think about method.
My postdoctoral advisor was a very unusual scientist. He was only a year and a half older than I was, extremely young, and completely distinctive. After I joined his lab, I gradually began to understand what genuine critical thinking and real methodology look like.
When I was a doctoral student at Johns Hopkins University, my teachers told us to read Nature and Science, to read broadly, and to keep our knowledge wide. I did that. Then, after I joined my postdoc advisor’s lab, one day I read a cutting-edge paper in Nature in our field and went to discuss it with him seriously. He said, “I haven’t read that one yet. Let’s talk after I’ve read it.”
A month later, I read another paper and wanted to discuss it again. This time he even blushed and said, “I still haven’t read that one yet.”
Later I gathered the courage to ask him directly: do you even read papers? He said he does not. I was shocked and asked how, then, one develops scientific literacy without reading papers. He said scientific literacy has to do with the history of science and with the sources of major discoveries. It has nothing to do with the newest knowledge at the frontier. The newest knowledge only tells you, when you are doing research, where you stand in your own field and whether you are working on something that someone else has already done. That is all.
That was a huge shock to me, but it also changed me. I hope people can ask more why. Do not simply accept things because they have always been done that way. You have to challenge what came before.
3. Building critical thinking
Beyond changing your methodology, you also need the ability to challenge academic authority.
My doctoral advisor had already become a full professor and department chair at the age of 33. He once said that even in his dreams he was still thinking, and that every day of his life was filled with thought. He often said, “Doubt is the driving force of scientific discovery.”
One day at a group meeting, he seemed unusually excited. He said he wanted to show us an idea and asked everyone to help find the problems in it. He began writing equations on the board. After a full blackboard of derivation, he step by step “proved” that the second law of thermodynamics was wrong.
We were all stunned.
Later, I found three mistakes in the formulas he had written, but I did not dare say anything at first. Then I thought about it again and realized they really were mistakes. My hands shaking, I raised my hand and pointed out one of them. All the other students said I was wrong, but our young boss said, “I think Yigong made a good point.”
After that, people in the institute would start greeting me first when they saw me. Little by little, I became more confident. That experience—publicly gathering the courage to correct a department chair and lab advisor’s academic mistake—gave me enormous confidence in my research path. Even now, it still affects me greatly.