The Impact of the Highly Improbable
By Nassim Nicholas Taleb
Find it on Bookshop
Summary
In The Black Swan, Nassim Taleb presents a well-constructed argument for why you need to be careful making predictions or generalizations about the world based only on your personal experiences. The world may work one way most of the time, but sometimes something entirely unexpected happens. Those rare but often dramatic deviations (“black swans”) tend to have an outsized impact on your worldview. Taleb explores the various innate human reasons why this happens.
The title comes from an example of the phenomenon. If you have only ever seen white swans, and continue to see only white swans, you may believe that all swans are white. With every white swan you see, you will feel more secure in your belief… until the day you see a black swan. Instantly, your worldview is uprooted and your belief is invalidated. Black swans are rare, but they do exist.
This book is fairly technical (Taleb himself points out parts where non-technical readers can skip large parts of certain chapters). It is a slow-moving, difficult book, but is extremely interesting if you have some background and interest in statistics.
“We” are the empirical decision makers who hold that uncertainty is our discipline, and that understanding how to act under conditions of incomplete information is the highest and most urgent human pursuit.
Main Points
The three key attributes of a black swan are unpredictability, consequences, and retrospective explainability.
Unpredictability
Black swans are unpredictable. People often confuse rare events for periodically occurring ones. For example, if a large hurricane hits an island once in twenty years, it is easy to think that the following year you will be safe. Note that the opposite is also true: it is also a black swan if the highly expected does not happen.
Most of the time, you can ignore outliers, because they are rare and most of the time irrelevant. But outliers do happen, and you can’t be too surprised when they do.
In real life you do not know the odds; you need to discover them, and the sources of uncertainty are not defined.
Consequences
Black swans have consequences. Taleb tells us that removing the 10 biggest one-day changes from the US stock market over the past 50 years makes a huge difference in overall long-term returns. But the problem is that studies of finance tend to see them as anomalies— exceptions rather than the rule. But they are a huge part of the story.
Terrorism kills, but the biggest killer remains the environment, responsible for close to 13 million deaths annually. But terrorism causes outrage, which makes us overestimate the likelihood of a potential terrorist attack—and react more violently to one when it happens. We feel the sting of man-made damage far more than that caused by nature.
Retrospective Explainability
Once we have seen a black swan, whether a good or bad one, we tend to expect it to happen again in the future. This is because of the narrative fallacy. This term refers to our tendency to turn events into stories that generalize and fit our worldview. The stories fit in our brains better than millions of tiny details.
Unfortunately, when we tell ourselves these stories, the black swans tend to get left out. After a black swan occurs, it is easy to look back with hindsight and tell yourself a linear story where it was obvious the black swan would occur. But before it happened you really had no way of knowing.
You need a story to displace a story. Metaphors and stories are far more potent (alas) than ideas; they are also easier to remember and more fun to read.
Examples of Black Swans
I was going to use the COVID-19 pandemic as a relatable example of a black swan. It appears to fit the bill perfectly: it seemed to come out of nowhere, it had (and is still having) an enormous impact on the world, and looking back, it’s obvious that it happened.
In reality, a global pandemic was entirely predictable, and in fact was predicted by scientists (documented in David Quammen’s book Spillover), and forewarned by many people, including Bill Gates. In fact, Nassim Nicholas Taleb gets “irritated” whenever someone refers to the pandemic as a black swan.
Better examples of a black swan include the computer, the Internet, and the laser. None of them were invented with the foresight of how we would be using them today, and each took a long time to be appreciated.
We build toys. Some of those toys change the world.
Note: The Antilibrary
This book is also the source of one of Taleb’s more famous ideas: that of the antilibrary. He argues that a large collection of unread books on your shelf is a good reminder of how much you don’t know.
Takeaways
You can’t expect a black swan to occur, but you can be prepared for the chance that it might. As The Psychology of Money puts it, “The correct lesson to learn from surprises is that the world is surprising.” Remember the three aspects of a black swan:
- Unpredictability
- Consequences
- Retrospective Explainability (narrative fallacy)
Want to read more? Find The Black Swan here: Bookshop
The quotes above were gathered using Readwise. It’s a truly amazing app to help you remember what you read. If you want to try it out, use my link and we both get a free month 🙂
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You might also like my notes on:
A Mind for Numbers by Barbara Oakley, PhD
The End of Everything (Astrophysically Speaking) by Katie Mack