art of thinking clearly

Book summary: The Art Of Thinking Clearly by Rolf Dobelli

Hello, world,
In this post, I summarize the book The Art Of Thinking Clearly by Rolf Dobelli. This book has some interesting observations about thinking clearly. I have listed out the main ideas in bold, its summary from respective chapters, along with my thoughts and view points.

Introduction to Thinking Clearly

Failure to think clearly is called a cognitive error by experts. It is a systematic deviation from logic. Logic is optimal, rational, reasonable thought and behaviour. The surprising thing is that it is systematic and not occasional error.

Art of Thinking Clearly: Why You Should Visit Cemeteries

In this chapter the author talks about survivorship bias. In real-life success is more portrayed than failures. This reminds me of the aircraft bullet hole story often found online. The story is about figher airplanes in World war 2 which were able to make it back to base had bullet holes in wings not in tanks. This connects back to my insight of seeing the non-obvious. Why we use controls and cased in a scientific study. We find what we look for, like the idea of convolution. It is a blessing and curse at the same time. It is a kind of selection bias. One example is A stock index is not the indicative of a country’s economy.Failed and small businesses do not enter the stock market. One question came to my mind at theis point. Is the GDP is a good indicator of a country’s economic progress?

Art of Thinking Clearly: Does Harvard Make You Smarter

He claims most of the advertisement work because of what he calls the swimmer’s body illusion. People going to study MBA are far privileged than others and getting better pay can make the swimmer’s body illusion. This points towards the role of other factors whch are not obvious at first sight.

Art of Thinking Clearly: Why You See Shapes In The Clouds

Here he talks about the clustering illusion. In data, how do we see patterns which are not actually there?. Humans are notorious to relate random things to physical reality without much scientific or rational backups. It seems evolution shaped me that way. He mentions testing the randomness statistically. I remind me about universal approximation theorem. Given enough examples it should be able to find the rule to produce data.

Art of Thinking Clearly: If Fifty Million People Say Something Foolish, It is Still Foolish

Here he talks about social proof or herd instinct. He shares a strikingly important psychological result of people relying on other people to judge. This might be the reason why many people follow religion. The possible reason he gives is evolution. Those who didn’t follow the herd end up dead and we are the successors of those who followed the herd. There are cases where we can make use of it like selecting a food counter to buy food from (the one with a lot of people). One example the author discussed is about Comedy programmes which insert laughter at points. This made me think of the question, why do people go after Iphones?. Can they name some features of it which they like the most?.

Art of Thinking Clearly: Why You Should Forget The Past

Sunk Cost Fallacy is the topic of this chapter. To me it seemed an excellent thought. He says we don’t reject some activity just because we spend time, energy and money for it even if we are convinced that the activity is boring or useless. As the saying goes, forget the past but remember the lesson. No matter how much you have invested, only your assessment of future costs and benefits counts.

Don’t Accept Free Drinks

The idea of reciprocity is explained here. Reciprocity is the extreme difficulty for people to be in another one’s debt. Again he gives an evolutionary explanation for this behavior. It is bad because, if I accept a free gift once later it will affect one or many of my rational decisions. 

Beware the Special Case

Here the topic is confirmation bias and says it is the mother of all misconceptions. We filter any information which contradicts our existing views. The special case could be showing that we are having confirmation bias. The only way to avoid is to actively look for contradicting opinions. When you are having a belief or theory you should start disproving it first.

Murder Your Darlings 

Here he shows more examples of confirmation bias. Religious beliefs, astrologers, economists, business journalists are all suffering from this. Is creativity make google thrive should be examined objectively using data. He even criticizes meditation.

Don’t Bow to Authority

Employees or subordinates are less likely to go against the opinion of the leader of the Head or CEO. This reminds me of the psychological safety given by Google on features of best teams. Whenever we are about to make a decision, think about an authority who might influence your decision. If you find one try your best to challenge them. 

Art of Thinking Clearly : Leave Your Supermodel Friends at Home

The contrast effect is explained here. Just like we feel no sweetness to tea after having a very sweet item. We have difficulty with absolute judgment. All industries that offer upgrade options use this trick. We will bargain more for small price items. We don’t notice small gradual changes. Width of a road getting narrower. A magician deviates our attention. You will look more beautiful or ugly depending on who you stand beside. 

Why We Prefer A Wrong Map to None At All

Availability Bias: We create a picture of the world with examples that easily come to our mind. We fail to notice that the other examples also exist just as frequently as others. This is because we are not thinking quantitatively. If something is repeated enough it gets into our mind and it doesn’t even have to be true. People prefer information that is easy to obtain. We tend to use the wrong tool in the absence of the correct tool than using no tool at all. It’s like when the key is lost you look at the place where there is light even though you are sure that the key is lost in a dark place. 

Why You Should Keep A Diary

Hindsight Bias. He says this is difficult to overcome. We think we are better predictors than we actually are. Keeping a Journal and making predictions about yourself will reveal your prediction skill later in your life.

Why You Systematically Overestimate Your Knowledge and Skills

This is about the overconfidence effect. There is a difference between what people know and what they really know. This is the Dunning–Kruger effect I think. Intelligent people underestimate themselves and not intelligent people overestimate. Why do most people think they are good in their skills because there is less number of knowledgable people? 

Don’t Take News Anchors Seriously

Here he talks about real knowledge and Chauffeur knowledge. He mentions the circle of competence. What lies inside it is what you know intuitively. What lies outside you may only partially comprehend. You have to know what you understand and what you don’t. It is not important how big the circle is. But it is important to know the perimeter. You have to figure out where you have an edge. True experts recognize the limits of what they know and don’t know. 

You Control Less Than You Think

The illusion of control. The illusion we experience having control over things which we don’t actually.

Never Judge a Decision by Its Outcome

Named as outcome bias this connects to the story of Monkey stock market prediction. We tend to evaluate decisions based on the result rather than the decision process. This means if you are assessing a decision that happened in the past do not get biased just because the decision turned out to be right because of the outcome it predicted. We have the tendency to favor the decision if it was right when we retrospect later because we are impressed/biased just because the decision turned out to be right. A decision that proved to be wrong later cannot be solely judged based on its outcome; rather it should be evaluated based on the data available in that time and the decision process. You should assess the process, not the result, especially when randomness and external factors play a role. A bad result does not indicate a bad decision and vice versa

Less Is More. 

The Paradox of Choice. When there is a lot of variety of choices it is difficult to make a choice. 


To me, the book has some big ideas which we often don’t pay much attention to. The psychological factors which affect our day to day life was an eye-opener to me. I recommend this book to anyone interested in philosophy and/or psychology. If you are looking for more such ideas but with a different technical or mathematical angle, check out some of my other posts.

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