It’s a common debate. Is depth more valuable, or is breadth more valuable? In a highly competitive and specific research field, depth of knowledge and skill might get you further. On the other hand, as a management consultant you might be better served by having a variety of experiences to draw from in solving day to day problems in an organization.
Although there are supporting reasons for both, my take on this is that depth should come first, and only after understanding a subject or skill deeply should you pursue breadth.
When learning something deeply, you need two things: time and intensity. Long, uninterrupted stretches of time allow you to dedicate your thinking to a particular subject or skill, where you are free to fully explore each level of the subject before examining the next. This helps you see all sides of the subject and why it is the way it is. You complement this with intensity, which is how much you are pushing yourself beyond your current abilities. The two combined, time and intensity, offer an ideal playground for exploring a subject deeply.
Out of these two, the most important one to focus on is intensity. It’s important to find dedicated blocks of time, but once that is figured out, you might find that you can hack your progress with intensity.
If you’re learning to solve mathematical problems, for example, and you want to at least get somewhat skilled in that, your one hour of study time cannot be a leisurely stroll through the park, sightseeing a differential here and an algebra there.
Your brain has to hurt after solving each problem. Luckily, the next time you try that problem again, you’ll find that your brain doesn’t hurt, and you can tackle a slightly harder problem. This kind of progress is very incremental, and it’s almost impossible to see the progress day to day, week to week, so it’s easy to dismiss your brain hurting and choose the leisurely stroll instead.
If you master the art of intensity, then you’ll find that you can accomplish a lot more in the same amount of time.
Seeing the results of this in one area of depth, whatever it may be, and forming the habits for going deep and working intensely, allow you to see that you were able to become skilled or knowledgeable in an area that you previously thought you had nothing to do with. This is the first reason why depth should come first.
It seem obvious from an outside perspective. If you study long and hard, of course you’ll learn and improve. Why go through the trouble of depth then? It’s because imagining what it’s like is one thing, and actually experiencing it is another. It’s one of those “mistakes that you just have to make yourself”, although in this case it’s not really a mistake.
Knowing how to go deep in one area, you can then use the same techniques for going deep in another, and faster than most other people. This is the second reason. Regardless of what you may go deep in the first time, the next subject you tackle, you will have the habits necessary to learn faster than you previously could.
The third and final reason is that you can see and understand nuances that you simply cannot from a breadth-only or breadth-first mindset. You’ll see that at a certain level of depth, there are almost always nuances that put generalizations into perspective. This is more important once you transition to breadth, because although you’ll be looking at things from miles away, you’ll have those experiences of depth in the back of your mind, and you’ll know that whatever you are seeing is probably not the whole story. You’ll be more open minded as you’ll always leave some room for things you don’t expect.
That’s why a better approach to this debate is not to choose either side, but learn how each complements the other.
Depth first, so that you form the habits for learning in the most effective manner and see that you are capable of learning something that seemed impossible at first, and so that you know that things are not always the way they seem.
Then breadth, to be able to move laterally when required and find things that are worth going deep in.