“If 50 million people say something foolish, it is still foolish.”
With over 99 different ways to overcome errors in thinking, it’s hard to pinpoint which ones are the most important. Instead, I will highlight the ones which are most relevant to myself.
These errors in the way we think influence absolutely everything in our lives, from our own introspection, to our friends, and communities.
Here’s the thing — I’ve been reading about behavioral psychology for years, and every book I pick up references the same core biases. But Dobelli managed to compile them all into one tight, digestible catalog. Think of it as a reference manual for your own monkey-brain. You keep it on your desk and flip back to it when you catch yourself doing something irrational — which is basically every day.
Key Thinking Errors
Survivorship Bias: Always looking at success stories, yet not looking at the data of how many people failed.
Social Proof: If many people are doing it, then it must be true, and I can or need to do it as well.
Sunk Cost Fallacy: I’ve already spent time or money on this, so it would be a waste to give up now.
Reciprocity: Because this person did this for me, I owe them something now.
Authority Bias: Because this important-looking person says this is true, or says I should do this, then I guess I should.
It’ll Get Worse Before It Gets Better: No pain, no gain. Well, pain isn’t a necessary prerequisite, nor is there potential for gaining anything.
Story Bias: Stories sound much better and inspire us to do more, despite their lack of data, facts, and reality.
Liking Bias: Similar to the authority bias, we give more points to someone we like, despite them either being wrong or not having our best interests in mind.
Endowment Effect: Similar to hoarding, we place emotional value in things and therefore keep them around for longer, or can potentially overvalue them.
Coincidence: You were thinking about a person, and they just happened to call. This is coincidence. You probably thought about them many more times, and yet they didn’t call.
Groupthink: Similar to social proof. Because everyone thinks the same, therefore it must be the best course of action.
Scarcity Error: When we don’t have it, we want it even more.
Loss Aversion: Losing something affects us more than gaining something. Marketers and salespeople frame their messages to make us think we are losing something by not buying now.
Halo Effect: We believe attractive, tall, physically capable people have more authority on a topic, or should be allowed to gain more in life.
Framing: Once again, marketers, salespeople, public relations, and anyone in communication will present a message that is most beneficial to their cause, despite the lack of factual data. This is also important for creating emotional value, such as maintaining confidence when times are tough.
Hedonic Treadmill: Inspired by envy, this is the “be careful what you wish for” idea. You don’t need the nicer car or the bigger house.
Association Bias: Experience can damage your judgment. Experience can build intuition, but events never occur identically twice.
Beginner’s Luck: You got off to a great start and had a few wins, but there is a huge drop before waiting, followed by real success.
Cognitive Dissonance: Lying to oneself is difficult, as well as lying to others. But over time, you will start to believe your own lies.
Hyperbolic Discounting: You can’t live free and do anything you want, because this just wouldn’t work.
Effort Justification: Similar to no pain, no gain. The more effort we put into something, the more we deem it worthy.
Affect Heuristic: Why you are a slave to your own emotions.
Neomania: Addicted to getting the brand new, coolest thing out there.
Sleeper Effect: Marketing and propaganda work on you. But it takes time for it to settle and kick in. You won’t even realize it when it does.
In-Group and Out-Group Bias: We identify with our sports teams, religious organizations, corporations, and friends. This can be beneficial, or lead to a really bad course of events.
Fear of Regret: Used by marketers as “your last chance.”
Procrastination: One of the big ones affecting everyone, and why New Year’s resolutions don’t work.
Planning Fallacy: Why you take on too much, and why none of it ever gets finished.
Illusion of Skill: Why technology often matters more than the actual skill of the person.
Cherry-Picking: Very similar to survivorship bias. We look at successful situations and group them together, yet avoid looking at unsuccessful outcomes.
Fallacy of the Single Cause: We look for a scapegoat when something bad happens, yet more complex circumstances are at play.
News Illusion: And finally, I have decided to ignore the news due to its low relevance to everyday life.
Why This Matters
So why should you care about a list of thinking errors? Because once you see them, you can’t UNSEE them. They show up in advertising, in politics, in how your friends argue on social media, and most importantly, in your own decisions.
The ones that hit me hardest were the sunk cost fallacy and loss aversion. As someone who’s built businesses online, I’ve thrown good money after bad on projects that clearly weren’t working — just because I’d already invested so much. Dobelli finally gave me the language to call it out in real time.
And loss aversion? That one is EVERYWHERE in internet marketing. Every countdown timer, every “only 3 left in stock” label, every “your cart expires in 10 minutes” popup — it’s all loss aversion weaponized. Once you understand the mechanism, you start seeing through the tricks. You won’t become immune, but you’ll hesitate before clicking “Buy Now” at 2 a.m.
The book’s format — short, independent chapters, each covering one bias — makes it perfect for dipping in and out. Pick a random chapter, learn a new mental trap, and move on slightly less irrational than before.
Final Thoughts
I’ve only covered a few thinking errors, and in very minute detail. It’s important to at least become consciously aware of the errors, even though you will still make them, but at least at a lower frequency.
If you enjoyed Predictably Irrational or Influence by Cialdini, this book fits right alongside them. It’s less academic and less structured, but it covers MORE ground than either. Consider it the encyclopedia of cognitive biases — one you’ll actually want to read.
Great book for thinkers. A++.
Thanks for reading.
— Leonidas
