Survivorship Bias 101

History is written by the victors. But if we exclusively focus on these successes, we allow survivorship bias to distort our understanding of the world.

But what is "survivorship bias" and how does it work?

Here's Survivorship Bias 101!

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1/ First, a few definitions.

Survivorship bias is the logical error of concentrating on survivors (successes) and ignoring casualties (failures).

When we do so, we miss the true "base rates" of survival (the actual probability of success) and arrive at flawed conclusions.

2/ When we completely ignore failures, we lose our ability to correctly identify the differences between successes and failures.

Put simply, exclusively focusing on successes may actually inhibit our ability to identify (and replicate) the actions that led to such success.

3/ Cicero wrote on the topic over 2,000 years ago.

An atheist named Diagoras is shown portraits of people who prayed and were saved from death at sea as proof of God's existence.

Diagoras replies, "I see those who were saved, but where are those painted who were shipwrecked?"

4/ Cicero cuts right to the point - we cannot conclude that prayer led to being saved from the sea if we ignore those who prayed and then drowned.

Survivorship bias can lead to a deeply-flawed understanding of cause-and-effect relationships.

Let's look at some examples.

How to Win (without talent or luck):

Operate in Your Zone of Genius

Your Zone of Genius is where your interests, passions and skills align.

Operating in your Zone of Genius means playing games you are uniquely well-suited to win.

Once you identify it, you can stop playing *their* games and start playing *yours*.

Adopt a Positive Sum Mentality

Want to get ahead in life? Start genuinely rooting for others to succeed.

When one of us wins, we all win—winning spreads.

If you adopt that mentality, you’ll become a magnet for the highest quality people.

Speak Up

Closed mouths don’t get fed.

A little push goes a long way. Don't sit back and wait for good things to happen.

If you want something—and you’ve put in the work for it—ask for it.

Worst case: you’re told no and nothing has changed.

Best case: it’s yours.

Play Long-Term Games

Life is the ultimate long game.

Those with low time preference play it more effectively—they happily delay gratification to allow compounding to work its magic.

In a world of people seeking instant gratification, this is a meaningful edge.

Circle of Competence 101

Warren Buffett and Charlie Munger often reference the importance of knowing the boundaries of your circle of competence.

But what is a Circle of Competence and how does it work?

Here's Circle of Competence 101!

1/ First, a few definitions.

A Circle of Competence is the set of topic areas that align with a person's expertise.

If the entire world of information were to be expressed in a circle, an individual's Circle of Competence is the small sub-circle that represents their expertise.

2/ The idea surfaced in the 1996 BH annual letter.

"You don’t have to be an expert on every company...you only have to be able to evaluate companies within your circle of competence. The size of that circle is not very important; knowing its boundaries, however, is vital."

3/ A Circle of Competence is built over time.

It is built through experience, reading, dedicated study, and effort.

It is dynamic, not static.

It can expand as you deepen your knowledge in new areas. It can contract if you fail to nurture your existing areas of expertise.

4/ To engage this mental model in your life, there are two key processes to go through:

(1) Identify what falls within your circle
(2) Identify the boundaries of your circle

(1) is all about figuring out what you know, while (2) is about humbly admitting what you don’t.

Incentives are everything.

Here’s a framework for establishing incentives (that actually create desired outcomes):

Great incentives create great outcomes.

But unfortunately, humans are astonishingly bad at establishing incentives—we consistently invite manipulation and unintended consequences.

This thread shares my framework for a establishing better incentives:

Incentives are anything that drives an individual to act in a specific manner.

Intrinsic incentives are internal—created by self-interest or desire.

Extrinsic incentives are external—created by outside factors (reward, punishment).

Today, we'll focus on extrinsic incentives.

In a very simple model, extrinsic incentives typically involve two key components: the measure and the target.

The measure is the metric that the individual or group will be judged upon.

The target is the level of the measure at which a reward (or punishment) will be initiated.

The problem?

This simple model of incentives—which will feel familiar to many—often leads to undesirable outcomes and unintended consequences.

Goodhart's Law explains why:

When a measure becomes a target, it ceases to be a good measure.

Dunning-Kruger Effect 101

In a year when the markets have minted many new self-proclaimed geniuses, it is worth remembering the Dunning-Kruger Effect.

But what is the Dunning-Kruger Effect and how does it work?

Here's Dunning-Kruger Effect 101!

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1/ First, a few definitions.

The Dunning-Kruger Effect is a cognitive bias in which people with low ability at a given task are prone to overestimate their ability at that task.

Put simply, humans are notoriously incapable of objective evaluation of their competency levels.

2/ The cognitive bias was first identified by psychologists David Dunning and Justin Kruger in a 1999 study.

Their paper, entitled Unskilled and Unaware of It, summarized, "People tend to hold overly favorable views of their abilities in many social and intellectual domains."

3/ The two men had studied the bizarre case of McArthur Wheeler, a 5'6" 270lb bank robber who was swiftly caught after robbing two banks in broad daylight.

He hadn't worn a mask.

Instead, he had put lemon juice on his face, believing it would make him invisible to cameras.

4/ Wheeler was aware that lemon juice was used as invisible ink, so (incorrectly) inferred that it could be used to make himself invisible to security cameras.

Even after he was caught, he was legitimately incredulous that his plan with the lemon juice hadn't worked.

I recently found out I'm going to be a father.

Here are the principles I want to teach my child to live by:

Be Interested

Talent is overrated—interest is not.

Interested people are prone to giving their deep attention to something to discover more about it.

They ask questions, listen, & observe. They open up to the world around them.

Being interested is a key to a fulfilling life.

Different is Beautiful

Growing up, I feared being different—I desperately wanted to fit in.

I made bad decisions grounded in insecurity.

I only realized later: being different is your edge—your ultimate competitive advantage.

No one can compete with you, at being you.

Work Hard

If you want to accomplish anything in life, you have to work hard.

Don't believe the hype. Hard work isn't the sexy, flashy Instagram posts saying "rise & grind”—it's the ugly, painful effort in the dark, when no one is watching.

If you want something, go get it.

Show Up in the Darkest Hour

It's easy to be there for people to celebrate their wins.

It takes character to show up for them in their darkest hour.

People never forget who supported them when the chips were down.

Be the friend who is always there—in good times and bad.

1/ Short Selling 101

With the markets continuing to rally, there has been more talk of “shorting” or “short selling” stocks.

But what does that mean and how does it work?

Here’s a quick educational primer: Short Selling 101

2/ When you believe a stock is going to rise in value, you are said to be “long” the stock (“bullish”). When you believe a stock is going to decline in value, you are said to be “short” the stock (“bearish”).

Short selling is simply how you bet on the decline in value.

3/ Imagine you read that Colombia is experiencing a very wet Summer.

You believe this will lead to a huge coffee harvest, flooding the market with coffee and driving down the price. You want to profit from this.

So you borrow a bag of coffee from Jimmy, your neighbor.

4/ You sell the bag of coffee to Paul, your other neighbor, for $20, the price of the bag at your market.

You now have $20 but you owe Jimmy a bag of coffee (you borrowed it, after all).

One month later, the price of coffee drops 50%. You buy a bag at the local store for $10.

5/ You walk over to Jimmy’s house, hand him the new bag of coffee, and give him $1 as interest on the borrowed bag.

So you sold a borrowed bag for $20 and then bought it back and returned it for $11 ($10 plus $1 interest).

You’ve made $9 profit on your coffee “short” position!

21 lessons learned in 2021:

Engineered Serendipity

I believe that some of what we call "luck" is actually the macro result of 1,000s of micro actions.

Your daily habits can put you in a position where "luck" is more likely to strike.

Increase your serendipity surface area.

Engineer your own serendipity.

Pessimists Sound Smart, Optimists Get Rich

Pessimists look at the future and see the doors that are closed.

Optimists look at the future and see the doors that are open—and probably kick down the closed doors, too.

Surround yourself with optimists. The future is bright.

The Exponential Growth Challenge

Human brains cannot fathom the insane power of exponential growth. We consistently underestimate its impact.

When you're on an exponential growth curve—stop trying to set specific goals.

Strap in, keep your head back, and enjoy the ride.

Work Like a Lion

Most people are not wired to work 9-5.

Modern work culture is a remnant of the Industrial Age—long periods of steady, monotonous work.

If your goal is to do inspired, creative work, you have to work like a lion.

Sprint when inspired. Rest. Repeat.

Frameworks provide clarity in complex situations.

Here are 20 useful frameworks (on startups, investing, writing, & life):

The Feynman Technique

To learn anything:

Step 1: Identify a topic.
Step 2: Try to explain it to a 5-year-old.
Step 3: Study to fill in knowledge gaps.
Step 4: Organize, convey, and review.

True genius is the ability to simplify, not complicate.

Simple is beautiful.

Directional Arrow of Progress

"Study the undeniable arrows of progress." - @wolfejosh

The future is extremely difficult to predict—but there are clues.

Look at the trend line of progress and where it's pointing—directionally, not precisely.

Invest (or build) accordingly.

The Eisenhower Decision Matrix

Place all of your tasks on a 2x2 matrix of urgency and importance.

(1) Important & Urgent
(2) Important & Not Urgent
(3) Not Important & Urgent
(4) Not Important & Not Urgent

Prioritize, delegate, or delete accordingly.

The Regret Minimization Framework

The goal is to minimize the number of regrets in life.

When faced with a difficult decision:
(1) Project yourself into the future.
(2) Look back on the decision.
(3) Ask "Will I regret not doing this?"
(4) Take action.

A “razor” is a rule of thumb that simplifies decision making.

The most powerful razors I’ve found:

The Feynman Razor

Complexity and jargon are used to mask a lack of deep understanding.

If you can’t explain it to a 5-year-old, you don’t really understand it.

If someone uses a lot of complexity and jargon to explain something, they probably don’t understand it.

The Luck Razor

When choosing between two paths, choose the path that has a larger luck surface area.

Your actions put you in a position where luck is more likely to strike.

It’s hard to get lucky watching TV at home—it’s easy to get lucky when you’re engaging and learning.

The Arena Razor

When faced with two paths, choose the path that puts you in the arena.

It's easy to throw rocks from the sidelines.

It's scary and lonely in the arena—but it's where growth happens.

Once you're in the arena, never take advice from people on the sidelines.

The Optimist Razor

When choosing who to spend time with, prioritize spending more time with optimists.

Pessimists see closed doors. Optimists see open doors—and probably kick down the closed doors along the way.

Remember: Pessimists sound smart, optimists get rich.

I turned 30 recently.

While far from old and wise, I have learned a few things along the way - on life, business, writing, investing, and growth.

Here are a few important lessons learned...

Embrace Failure

Put simply, failure leads to growth.

Do not hide from failure. Seek it out. Allow yourself to be uncomfortable. Embrace it.

The most transformative moments in your life will always come from failures.

Stand on the Shoulders of Giants

As Isaac Newton famously wrote, “If I have seen further, it is by standing on the shoulders of giants.”

You will only go as far as you can see.

Seek out mentors who champion your cause and empower you to see further.

Prioritize People

Everything in life comes down to people and relationships.

Networks compound as well as any financial investment.

Build an army that is deep and wide.

Cultivate deep relationships, but also learn to appreciate the power of weak ties.

Give > Receive

Focus on what you can do for others, not what they can do for you.

Give more than you receive.

This mentality will lead to more success and growth, but also to more fulfillment and joy.

10 common mental errors that derail decision-making:

Survivorship Bias

History is written by the victors.

But in studying and learning from "survivors”—and systematically ignoring "casualties”—we create material distortions in our conclusions.

We overestimate the odds of success because we only read about the successes!

Naïve Realism

Humans generally think very highly of themselves.

We tend to believe that we see the world with perfect objectivity.

We also assume that people who disagree with us must be ignorant, uninformed, or biased.

This error sits at the core of many societal problems.

The Dunning-Kruger Effect

Humans are notoriously incapable of objective evaluation of their own competency levels.

People with a low ability at a task are prone to systematically overestimate their ability at that task.

Example: Everyone is a genius in a bull market.

Loss Aversion

Humans tend to prefer avoiding losses vs. achieving gains—the pain of losing something is more powerful than the pleasure of winning it.

We will typically do more to avoid losses than we will to seek gains.

We systematically overvalue what we already have.

One cold email can change your life.

Here's how to write a great one:

I’ve sent (and received) a lot of cold emails—some great, some not.

What I've learned: a cold email success is never an accident.

The features of a great cold email:
• Short & Sweet
• Personalized
• Credentials or Social Proof
• Create Value
• Clear CTA

Let's cover each:

Short & Sweet

If you're sending a cold email to someone, remember that the person receiving it probably gets a lot of these.

They don't have time (or energy) to read through long and winding notes.

Keep it short and sweet.

Space out the text to make it optically inviting.

Personalized

No one likes a generic email—it's auto-deleted 99% of the time.

Personal touches make all the difference.

A few ideas:
• Reference a book they love
• Mention a podcast they were on
• Compliment their work

Make it clear you didn't send out hundreds of the note!

Credentials or Social Proof

Infuse credentials or social proof—i.e. reasons the person should take you seriously.

Don't be humble—let it shine.

What have you done or created that is interesting or notable? Who has engaged?

Show them they would be crazy to ignore your email.

11 harsh truths that changed my life (and may change yours):

Harsh Truth: You'll only see your loved ones a few more times.

In May 2021, I had a conversation with a friend that changed my life.

I was talking about living in California—so far away from my parents in Boston—when my friend asked how often I saw them and how old they were...

I said I saw them about once per year, and that they were in their mid-60s.

He said, "Ok, so you'll see them 15 more times in your life."

Gut punch. It sounds insensitive—but it's just real.

Our time is finite, but we fail to recognize it until it's too late...

Later that month, we sold our house in California and moved to the East Coast to be closer to our parents.

It was the best decision I've ever made.

I'll never regret those tiny moments—of doing nothing in particular—that we'll get to spend together in the years ahead.

Harsh Truth: Most of your friends aren’t really your friends.

They’re just along for the ride when it’s fun, convenient, or valuable.

Your real friends are the ones who are there for you when it's none of those—when you have *nothing* to offer in return.

Cherish them.

The Feynman Technique—how to learn anything:

The Feynman Technique is a foundational learning method that prioritizes simplicity and depth of understanding.

It was developed by Richard Feynman—an American theoretical physicist who won the Nobel Prize in 1965 for his groundbreaking work in quantum electrodynamics.

So yes, you could say that Richard Feynman was intelligent...

But there are a lot of intelligent people in the world.

Feynman's true genius was found in his ability to convey extremely complex ideas in simple, elegant, digestible ways.

He had observed that complexity and jargon are often used to mask a lack of deep understanding.

As a rule:

If someone uses a lot of acronyms, complexity, and jargon to explain something to you, they probably don’t understand it.

We've all encountered this type of "expert"...

The Feynman Technique is a learning framework that forces you to develop a deep, elegant understanding of a given topic.

It involves four key steps:
(1) Set the Stage
(2) ELI5 (Explain It To Me Like I'm 5)
(3) Assess & Study
(4) Organize, Convey & Review

Let's cover each step:

Life rules worth breaking:

Wait for the Perfect Moment

This rule has paralyzed would-be action-takers for generations.

The reality: there is no such thing as the perfect moment.

Sometimes you just have to open the door, jump out of the plane, and hope you packed the parachute tight.

You Have to Work Hard to Succeed

Hard work is important—but it's relative, not absolute.

In the Digital Age—when creative and inspired work stands out and is rewarded—what you work on is more important than how hard you work.

Play your game, not theirs.

You’ll play it better.

Let Things Play Out

This isn't a movie that you're watching on your TV. You are not a passive observer of your own life.

There are times to sit back, and there are times to push.

Learn to identify the difference and never be afraid to provide a little push.

Don't Ask Too Many Questions

Children are born with an insatiable curiosity, but somewhere along the line, we are told to stop asking questions.

The most successful people in the world never listened—they broke this rule.

Ask questions. Be curious. Be interested.

“Razors” are rules of thumb that simplify decisions.

The most valuable razors I’ve discovered:

The Smart Friends Razor

If your smartest friends are all interested in something, it’s worth paying attention to.

If that something seems crazy, it's worth paying a lot of attention to.

The passions of the smartest people in your circles are a looking glass into the future.

The Rooms Razor

If you have a choice between entering two rooms, choose the room where you are more likely to be the dumbest one in the room.

Once you are in the room, talk less and listen more.

Bad for your ego, great for your growth.

The Man in the Arena Razor

It's easy to throw rocks the sidelines—it's hard to step into the arena.

It's lonely and vulnerable, but it's where growth happens.

When faced with two paths, choose the path that puts you in the arena—choose the path with real skin in the game.

The Feynman Razor

Complexity and jargon are often used to mask a lack of deep understanding.

If you can’t explain it to a 5-year-old, you don’t really understand it.

If someone uses a lot of complexity and jargon to explain something to you, they probably don’t understand it.