Common Misconceptions about a PhD

This post addresses misconceptions regarding the doctoral degree (I will stick to physics) that I have come across in a career of about 30 years in academia now. These misconceptions come from people both within and outside of academia. I find it remarkable how many myths and legends have grown up around this institution (they vary all over the place, and in some cases even contradict each other).

1. A PhD is something you do if you cannot get a real job: PhD programs in physics are very competitive and have a high entry bar. It is unlikely that you will be able to get into one without solid credentials.

   
   

2. A PhD should be an earth-shaking piece of work: There is no such requirement, and to go in with such an expectation might be naive. This is because progress in research is very challenging to make, and world-advancing advances in physics are made only once in a while. I have seen even very intelligent and capable people go in expecting the PhD to give them an almost mystical revelation and be disappointed if it does not happen.

3. A PhD is the best piece of work you will do as a researcher: This rarely happens for people who go on to be researchers. The PhD is basically meant to train graduate students. So during a PhD they are basically in the process of being trained and their performance is likely not optimal yet. Further postdoctoral training (~5 years) is required before they become viable for faculty positions. About 5 more years are required before their position becomes permanent and they have the security (and other resources) to explore truly fundamental advances.

   
   

   So most people do their great work post-PhD. It is good to remember that although Einstein's thesis was outstanding (it was on Brownian motion and served to confirm the atomic hypothesis), it was not his best work (special and general relativity). An exception: John Martinis was a graduate student when he did Nobel-prize winning work that eventually got him to Stockholm in 2025. But of course it was his advisor (John Clarke shared + then postdoc Michel Devoret) who had the resources to set up the idea.

4. A PhD on average has no impact: I feel this is one of the most dangerous misconceptions and it has been incorrectly opined by some eminent leaders of industry (ahem).

   
   

   For the reasons mentioned above, i.e. since scientific advance is difficult to make, clearly every PhD will not constitute a breakthrough. However, this does not mean it is not impactful. Theses are like drops in the ocean of knowledge: each drop is small, but without the drops there would be no ocean.

   
   

   More specifically, the overall advance of science depends on many small steps taken in the past. These steps are not always easy to trace, since science does not work linearly. Every good thesis is a stepping stone on which some large and imposing structure can eventually be built. Typically a thesis at a university is a part of a grant contract designed to fulfill a larger aim. These grants are in turn parts of well-considered programs which yield substantial scientific knowledge, which sometimes can also spin-off into impactful technologies. It is the patient work of many theses which generates the conditions for the perfect storm of the big scientific breakthrough.

   
   

   Finally, the impact on the person being trained should not be minimized. A quick look at industry, government and academia will reveal that a great many of the movers and shakers are holders of doctoral degrees. The PhD training is aimed at creating independent thinkers and problem solvers at a very high level. Whatever the impact of their thesis work in terms of specific science, they go on to make an impact on society based in their training. Example: Chemistry Nobel Prize winner Demys Hassabis has a PhD in cognitive neuroscience, and is now one of the leading AI inventors in the world, at Google.

5. A PhD sentences you to a lifetime of poverty: On the contrary. Depending on which job your choose, you could be very well compensated.

   
   

6. You need to be a genius to do a PhD: Persistence and enthusiasm are bigger requirements than outstanding intelligence. As I never tire of repeating, a Dean once told me that the PhD is awarded for stamina.

   
   

7. PhD holders are elitists: The distribution of elitists among PhD holders is no different from that in the rest of the world.

   
   

8. Once you have a PhD you will know everything about the subject: You will never know everything about the subject.

   
   

9. Once you get a PhD, you are doomed to staying in academia: Industry and government agencies are filled with PhD physicists, not to speak of Wall Street and the finance industry, and of course other places.

   
   

10. A PhD involves just more coursework than a master's degree: Some coursework will be involved, but the main requirement is original research.

11. A PhD has to be completely original: Every thesis rests on work done before it, but also makes a substantial and original advance.

    
    

12. A PhD overqualifies you: You need it if you want to become a professor (Masters will not work). Some industrial positions (team leaders) will need it. It may be an overqualification for some jobs.

    
    

13. All PhD programs are the same: They may share some features in common (application procedures, graduation requirements, etc.). But they may have individual strengths (e.g. in certain disciplines).

    
    

14. PhD advisors will guide you every step of the way: Not always, and perhaps this is an important enough topic that it deserves its own post later.