Most People Think This Is A Smart Habit, But It’s Actually Brain-Damaging
This is the mental equivalent of eating McDonald’s every day.
Author’s Note: This article was written over 60 hours with love and care using the blockbuster mental model.
As someone who has studied, practiced, and taught learning how to learn for years, I’ve come to believe that one of the most pervasive threats to our brains goes completely unnoticed.
When we think of brain damage, we think of a head injury impairing a person’s ability to think. There are laws in place that require us to wear helmets, use seatbelts, and generally do everything we can to avoid head injuries. Why? Because we know how important our brain is for leading a fulfilling, impactful, and successful life.
But a knock on the head isn’t the only way to “impair” our brains. If we think of damage in broader terms, then brain damage can be caused by anything that physically changes our brains in a way that makes us less intelligent or functional. Using this definition I’d make the case that much of the learning that people do on their own, which we usually consider a positive thing, might actually be doing many people more harm than good.
Let me explain.
First, Whenever We Learn Something New, Our Brain Physically Changes
More specifically, the brain either makes a new connection between neurons or strengthens an existing one.
In one fascinating study that shows how much learning can change our physical brain, researchers found that certain parts of the brain of London taxi drivers who completed the exhaustive training process were significantly larger than aspiring drivers who dropped out of the training program. This shows that the training program was the cause of the growth.
How learning impacts the brain is explained in detail in The Art Of The Changing Brain by researcher James Zull.
Second, Assuming That All Learning Is Inherently Good Is Like Assuming That All Food Makes Us Healthier
Or that most of the news we consume makes us more well-informed. In reality, the opposite is true. The default—the easiest thing to reach for—is often junk food and junk media.
The same is often true with learning. Just like eating McDonald’s doesn’t make us healthier, “junk” or “fake” learning doesn’t make us smarter. In fact, this kind of learning actually makes us dumber.
Learning is a circular process of taking in information, reasoning with that information, experimenting in the real world, getting feedback, and then taking what learn to go through the cycle again. When one part of the process is faulty, then it can throw off our learning process. For example, if all we’re collecting is bad ideas, then our reasoning is going to be bad, which is going to lead to ineffective actions and so on.
Later in this article, I’ll share five strategies to recognize junk learning and avoid it.
Next, Junk Learning Can Cause Physical Changes In Our Brain, Which Then Hurts Our Ability To Function Effectively
If the connections from learning are reinforcing false and harmful concepts, beliefs, or ideas, the physical result can be functionally equivalent to brain damage.
For example, one of the ideas I learned growing up was that sales is a bad thing. This single idea literally changed my brain and made me resistant to information on how to become better at this vital business skill. I had to go through a lot of pain before I was finally willing to let go of this idea. My business grew rapidly and immediately afterward.
In some ways, it was like I was walking through the world with a hand in front of my face making it so I had huge blind spots. As a result, my brain created a false sense of reality, which led to me bumping into things.
We particularly see how junk learning can be functionally equivalent to brain damage with political polarization. Imagine you had someone come from a completely different culture who was unaware of politics. Then, imagine you had her observe the inability of many political commentators to logically consider an opposing idea without distorting it and attacking the other’s character. That person could easily come to the conclusion that the commentators’ brains had been damaged. Now, consider that this phenomenon is in no way limited to politics.
Finally, Junk Learning Is Like A Disease That Spreads Throughout The Brain And Causes More Junk Learning
We all share inherent physical growth tendencies. When we’re born, we go through a set of predictable, sequential steps that build on top of each other.
We roll over before we sit. We sit before we stand. We stand before we walk. We walk before we run.
The same thing happens with our cognitive development.
Although it’s not as obvious as physical abilities, ideas in our brain build upon other ideas in a predictable order from simple to complex.
For example, when it comes to math, we start with single-digit numbers, move to double-digit numbers, then triple-digit, then addition, subtraction, multiplication, division, and so on.
Each new thing we learn is like adding a new brick and then cementing it to other bricks to create a knowledge structure.
As we learn more, our building becomes larger.
The problem comes when we build our buildings on a poor foundation with shoddy bricks (junk learning). In this case, counterintuitively, adding new knowledge weakens the whole building.
And if we keep adding new knowledge to an unstable building, it eventually falls down. These building collapses are our existential crises (i.e., quarter-life and mid-life crises) where we hit bottom after reconsidering our deepest beliefs. Removing these fundamental ideas forces us to reconsider all of the ideas that were dependent on that idea.
This is what happens in our brains with junk learning. For example, when I first started writing in college, I somehow got the idea in my head that the key to being a good writer was producing as much content as possible. So, for three years, I wrote a new blog post every day.
My hope was that the blog would somehow become viral and be a platform for me to go into a career in writing. Instead, almost no one read my posts, and I eventually gave up and took a different career path that allowed me to support myself. As a result of the experience, I came to the conclusion that I just wasn’t a good writer and that you can’t really support yourself as an independent writer. Two more false ideas built upon a bad one.
I didn’t come back to writing for 7 years. Fortunately, when I started writing for Forbes in 2013, I had just read a book called Blockbusters by Harvard professor Anita Elberse. The central premise is that the best strategy in the media world of books, movies, TV, and music is to focus on creating high-quality blockbusters rather than churning out volume. Elberse based her claims on years of research on who the winners are in the media world.
It is painful to think about how big of a detour was caused by the initial faulty idea.
Bottom line: Junk learning damages our brain and then it makes us more prone to more junk learning, which damages our brain even more.
The Top Five Sources Of Junk Learning
The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn.
Ok. So we’ve established a few things:
Learning physically changes our brains.
Much of the learning that people are exposed to by default is junk learning.
Junk learning is effectively equivalent to brain damage and impairs our ability to function in the world.
Junk learning is like a disease that spreads throughout the brain and causes more junk learning.
Now the question is, what do we do about it?
In my experience, it’s key to first know what the causes of junk learning are. This way we can avoid them the next time we jump into an audiobook or start a learning ritual.
What follows are the five biggest sources of junk learning that I’ve personally come across over and over…
Junk Learning Source #1. The “Facts” We Know Are Slowly Being Debunked
At the same time that we are building up our base of knowledge, the knowledge is expiring. The book that woke me up to this reality is The Half-Life of Facts: Why Everything We Know Has An Expiration Date, which terrified me by revealing that if you’ve got liver disease and go to a doctor who graduated more than 45 years ago, half of that doctor’s information is probably wrong:
It’s not just medicine. It’s happening in computer science, design, nutrition, psychology, basically everywhere. It’s like we’re trying to bail water out of a leaking boat. We have all this knowledge, but it’s losing value. And to make it worse, we don’t even know when a piece of knowledge expires. It’s not like we get an email notifying us: “Hey, that thing you learned three years ago? It’s not true anymore.”
The end result is that we operate with false ideas and we stop getting results. Then we have to troubleshoot to find out what out-of-date knowledge and skills might be responsible for the poor results.
A fascinating 1966 paper titled The Dollars and Sense of Continuing Education plays out the implications of decaying knowledge. Assuming that it takes ten years for half the facts in a given field to be proven wrong or improved on, then:
You would need to spend at least five hours per week, 48 weeks a year, to stay up to date.
A 40-year career would require 9,600 hours of continuing learning just to stay relevant. This does not include learning to get ahead or the time it would take to simply remember what we have already learned.
Now, if that isn’t enough to blow your mind, consider that 90 percent of the scientists who have ever lived are alive today. Each of these scientists is increasing the rate at which new information is created and old information decays. Also, consider that some of the most interesting and consequential future fields (for instance, artificial intelligence and cryptocurrency) change the fastest.
So what should we do in light of all of this change? One model I’ve found helpful comes from the world of personal finance.
One of the biggest distinctions in the world of personal finance is between purchases and investments. Purchases immediately lose value while investments have the potential to increase in value. For example, a car is a purchase—the second you drive a new car off the parking lot, it loses value. A home, on the other hand, is an investment: It has the potential to increase in value.
Learning is very similar. Certain knowledge is going to predictably decline in value. If you read the New York Times №1 bestseller about business or the latest fad diet, chances are it will be forgotten in a year. Other knowledge has the potential to become even more valuable: If you read a classic book that’s been around for centuries, chances are you will glean wisdom that is more universal and long-lasting.
Learning is like running on a treadmill. As the speed of the treadmill increases, you need to run faster or you’ll be thrown off. Similarly, as society changes more rapidly, you need to update your skills more rapidly or risk falling off into irrelevancy. Depending on outdated knowledge to get results in life is like depending on termite-eaten beams to hold a building up.
While you still need to keep on top of cutting-edge breakthroughs in a field, in general, many people undervalue learning investments in a stable base of knowledge that doesn’t change. In my opinion, mental models are one of the best learning investments anyone can make, because they apply across fields and across time, and will continue to apply to many situations in the future.
Lesson Learned: Look for information that actually increases in value over time. When it comes to knowledge, think like an investor, not a consumer.
If you’re just learning about mental models for the first time, my free email course will help you get started. My team and I have spent dozens of hours creating it. In the course, you will get the following goodies and more:
Mental Model Dictionary: Master list of hundreds of the top mental models, used by the world’s best mental model experts.
Charlie Munger (Warren Buffett’s long-time business partner) Top 25 Cognitive Biases: A report that summarizes Charlie Munger’s analysis of the 25 most damaging biases in decision making.
Mental Model Hacking: The #1 strategy to find and implement high-power hacks in each mental model.
Sign up for the free mini-course here >>
Junk Learning Source #2: A Little Knowledge Is Dangerous
The greatest obstacle to knowledge is not ignorance; it is the illusion of knowledge.
—Historian Daniel Boorstin
In 1999, psychologists Justin Kruger and David Dunning wrote a research paper, that introduced us to the Dunning-Kruger Effect.
The idea is simple but counterintuitive: In learning any new domain, our confidence is actually highest when we start. This is surprising because, rationally, we should have the lowest confidence when we know the least. However, Dunning and Kruger found that when we don’t know what we don’t know, we overestimate our abilities. Or, as philosopher Bertrand Russell famously put it: “The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.”
Of course, once we have our bubble burst and learn enough to recognize our ignorance, most people’s confidence takes a huge dip. It only slowly rebounds if we keep going. Unfortunately, many give up during the dip phase.
I’ve experienced the Dunning-Kruger effect myself. When I was 16 years old, Cal Newport and I co-founded a company together during the height of the dot-com boom. With barely any advertising we quickly got clients willing to pay us over $100 per hour. At the time, the only way I could explain this was that we were brilliant and everyone else who was decades older and making a lot less wasn’t. Then, in 2001, the Internet bubble burst and the business cratered. I learned that my self-confidence was wildly over-inflated, that I was missing key business skills, and that tech and economic cycles are a real thing.
It took several years for me to admit my ignorance because my self-image had been so big. And it took several more years to regain my confidence.
Lesson Learned: No matter how much we know, we only know a fraction of all there is to know. We must assume our own ignorance. An attitude of caution can help us avoid developing false beliefs that can lead to irrational decisions.