Six Thinking Hats by Edward de Bono: Book Summary

Want to run better meetings and make faster decisions? Use the Six Thinking Hats method described by Edward de Bono in his iconic book that encourages critical thinking.
Natalia Rossingol

You were unlucky to witness a car accident, and now you are testifying in court. Yes, you clearly remember the car that bumped into a glass wall of a store was black. The other witness looks at you with big eyes and objects, saying that the car was definitely white. The judge frowns, trying to understand who is lying... but, in fact, no one is. Because on the video recording, you can see that one half of the car was painted black, and the other one – white. Checkmate, you witnesses.

A big problem of traditional thinking is that people tend to think inflexibly, looking at things from one angle. What they see can be totally correct – however, what you see from a different angle will not be wrong either. Thinking like this, we desperately lack objectivity.

Edward de Bono, a Maltese physician, psychiatrist, and a philosopher, invented a concept of thinking that is drastically different from this one. Instead of a widely accepted Western-type thinking, which originated from the Greek civilization and which is based on argument and judgment, de Bono introduced so-called “lateral thinking” - an approach to solving problems that uses creativity and non-obvious reasoning. And a great example of lateral thinking is a method,which he described in his book “Six Thinking Hats”, a short summary of which you can read below.

The Six Hats Method 🎩

Thinking is an innate ability of a human being, which is as natural as breathing. Yet, trying to strain our brain, we often confuse ourselves and get mentally exhausted. Why does this happen? According to de Bono, the reason is that we get tangled in a web of information, emotions, creativity, logic, and many other things, which makes us disperse our energy.

Instead, de Bono suggests a different concept of thinking that would allow us to focus our attention at something specific, one thing at a time. He called this concept the Six Thinking Hats. Each hat stands for a different type of thinking. De bono explains that he chose this metaphor because a hat is something that can be easily put on and taken off – similarly, you can easily switch the way you think. Besides, a hat is visible, and in a sense, it is a way of communication. The colors of the hats are not random: they symbolically reflect the nature of each thinking type. We will analyze those a little later, in Edward de Bono’s “Six Thinking Hats” summary by chapter.

To use the Six Thinking Hats method, you can ask a person to think under this or that hat, or you can organize a sequence in which these hats will be used. It is very important to maintain discipline though: once you agree about putting on a hat, no one can switch to another one until the session finishes. This is very close to playing a game: we assume roles, and we agree to follow certain rules.

Below you can read about the “Six Thinking Hats” by Edward de Bono and learn more about each of them:

The White Hat

Imagine a computer that gives the facts and figures for which it is asked. The computer is neutral and objective. It does not offer interpretations or opinions. When wearing the white thinking hat, the thinker should imitate the computer.

The white hat means information. When you put this hat on, you ask yourself: what information do we have? What questions should we ask? What data do we lack? The information we request or give must be presented in the form of facts and figures; and as white is the absence of color, they must be devoid of any emotionality. The white hat excludes intuition, opinion, gossip, impression, and feeling. It makes you act like a scientist or an explorer.

However, it can be surprisingly hard to say for sure if something is really a fact since it can be just a likelihood. Besides, very often we take stereotypes or beliefs as facts, says de Bono. This is why he suggests differentiating between believed facts and checked facts. With the believed facts, we need to find out which of those can be useful, so we can further proceed with verifying them. But we should never present them as pure facts.

This way, the information that is likely to be true can be presented under the white hat – but only on condition that it is put in the right frame. Speaking spectrum of likelihood ranges from “always true” to “never true”, and in between we come across such frames as “usually true”, “occasionally true”, “been known to happen” etc, for example:

Cats can fall off roofs but that is not normal behaviour.

The white hat type of thinking is characteristic of Japanese culture, says the author. At a meeting, the Japanese participants sit at the table and listen to each other talk, without getting involved in an argument (the reason for it is probably the fact that their culture was not influenced by Greek philosophers and medieval monks trying to prove their opponents wrong throughout history). They do not have any ideas on their mind before the meeting, yet the meeting is never unproductive – because every person listens carefully and adds a piece of neutral information to what has just been said. This way, they create a full and objective picture.

Unfortunately, in the Western world, people conduct their meetings the opposite way: they come with a ready-made opinion and provide facts to support it. This provokes arguments and unnecessary chaos. And even though we cannot change our culture, says de Bono, we can still put on the white hat and pretend to be Japanese – for the sake of objectivity of our decision.

The Red Hat

Think of fire. Think of warmth. Think of feelings. Using the red hat gives you an opportunity to express feelings, emotions and intuition without any need to explain or to justify them.

In business life, emotions are considered as something inappropriate, if not taboo. But people are emotional by nature, and it’s not possible to get rid of a part of you. Even more, suppressing your feelings, you risk letting them boil up and erupt as a volcano. The red hat gives you a great chance to show your “illogical” side and reveal all that is bothering you, not getting judged.

That design is hideous. It will never catch on. It is a huge waste of money.

Using the red hat, you can express your enthusiasm, doubt, unhappiness, loyalty and so on. But (and this is very important) you are never allowed to explain or validate them. To describe your feelings, you can use terms like “confused”, “doubtful”, “undecided”, “mixed” (in this case you have to specify what exactly is mixed) etc.”

Despite the popular opinion that a good thinker must be cool, emotions are real, and can be very strong. They adjust thinking to our needs that we have at this very moment, and to the overall context of our situation. De Bono says there are three points at which emotions affect the way we think:

1.       Strong background emotions like anger, hatred, suspicion, love, etc. that color our perception.

2.       Initial emotions triggered by first impression, which can be very long-lasting.

3.       Emotions that appear after you see the whole situation.

In each case, the purpose of the red hat is to bring the emotions to the surface and see to what extent they influence our behavior.

Describing the red hat thinking, de Bono also mentions intuition: he says that even though intuition and emotions have different nature, they can still be put under the same hat to avoid complexity. There are two definitions of the term “intuition”, says the author: the first one explains it as an insight, the second one – as a result of judgment based on experience which leads to a sudden understanding of a situation. He uses the second definition. According to him, intuition must be seen as an advisor, not a mystic oracle; it is not infallible. If the advisor has been right before, we should probably listen to what he says.

All in all, the red hat covers feelings that are pretty simple, such as “like” or “dislike”, or more complex, such as suspicion and aesthetical feelings. It kind of legitimizes emotions and makes them visible – and this way, less dangerous and more useful.

The Black Hat

The black hat is the hat of survival. An animal has to learn which berries are poisonous and to read the danger signs of a predator. In order to survive we need to be cautious.

According to de Bono, the black hat is the most used and probably the most important one. It is the hat of caution that saves us from anything illegal, unprofitable, dangerous and so on. It points out everything that is contradictory or inconsistent, everything that does not fit our strategy, values, or ethics. It is the basis of critical thinking – so it is fair to say it is the basis of the Western civilization.

Living in this world, we develop our idea of how things should be; and if something stands out from this picture, we feel uncomfortable. Spotting this, we put on the black hat. However, since this hat is based on our natural survival mechanism, people tend to overuse it. This is where problems start.

The good news is that you can always change the hat. People who normally think negatively, can be surprised how different they can think under a different hat. This is why it makes sense to allot time for black hat thinking – like for any other hat. Like de Bono says, pasta is excellent food but if you eat it every day, you would not be enthusiastic about it.

Since the black hat points out “dark” aspects of things under discussion, its important function is risk assessment. It always concerns the future – but it has to be based on the past experience too. De Bono says it is very important to draw a line between “academic” and “real world” thinking: in the first case, we just analyze and provide explanations, but when it comes to risk assessment, we must take into account the action element as well:

What are the potential problems? What can go wrong?

Unfortunately, the black hat is often used as an instrument to demonstrate self-importance. As the author says, it is much easier to criticize a chair than to make it. So people are willing to criticize – they can make themselves noticeable this way: even if 95 percent of the idea is great, the other will still focus on the 5 percent someone criticized. Is this productive? Not always. This is why the overuse of it must not be allowed.

Finally, the author underlines that the black hat does not mean an argument, and should not grow into it: its purpose is to only highlight dangerous areas.

The Yellow Hat

Think of sunshine. Think of optimism. Under the yellow hat a thinker deliberately sets out to find whatever benefit there may be in a suggestion. Under the yellow hat the thinker tries to see how it may be possible to put the idea into practice.

As we mentioned before, people have a survival mechanism that protects us from dangers – however, we don’t have a mechanism that helps us see benefits and value. This is why it is harder to wear the yellow hat than the black one.

The yellow hat makes us artificially look for value. Spending time on it, we can find out that an idea that didn’t seem promising suddenly happens to be a very interesting one. All it takes is to look at it through a magnifying glass of optimism.

More and more people need to park in cities. How can we get some value out of that?

However, the yellow hat is not about fantasies. Trying to find values, you need to ask specific questions: Under what circumstances will you get them? From whom? Are there any other related values? In other words, all the “yellow” information must be logically based.

Normally, it’s our choice, to be positive or not. De Bono says that while for some people being positive is a natural state of mind, others can be positive only when putting forward the idea of their own, or when there is an element of self-interest. However, under the yellow hat, we don’t need any motivation – we just have to deliberately search for something positive. And yes, sometimes it’s futile. 

The author emphasizes that at some point, optimism can turn into foolishness – for example, some people seriously hope to win a lottery and live their life as if it will happen no matter what. So what are the restraints? De Bono says that positive thinking ranges from over-optimism to logical-practical viewpoint. And even though sometimes over-optimistic ideas seem extremely impractical, in fact, there have been cases when they came true. This is why, restricting our optimism, we block our ideas.

However, there is something that can be viewed as an indicator of a really good idea, no matter how impractical it looks: if it is followed by an action, then it can be tried out. And, vice versa, if you cannot think of any action that would follow your idea, then it’s just a hope that a miracle would happen.

The yellow hat is concerned with positive assessment. It makes you take a positive attitude and concentrate on effectiveness. It is about concrete proposals and suggestions; it is about making things happen. You can take an idea that is used elsewhere and try applying it in another sphere, if it really can work there. Overall, the yellow hat is the hat of opportunity – the hat of “what if?”

The Green Hat

The green hat is the energy hat. Think of vegetation. Think of growth. Think of new leaves and branches. The green hat is the creative hat. Under the green hat we put forward new ideas. Under the green hat we lay out options and alternatives.

You may or may not be a creative person, but when the green hat is in use, you are expected to make a creative effort. Even if you think you are boring, suddenly you can realize that you can generate brilliant ideas – and your confidence will immediately increase.

While the yellow hat is about opportunities, the green hat is about possibilities. Under the green hat, you look for totally new ideas, and escape from old ones. You try to change things. With the green hat, you do an experiment, and you don’t know what results you will get. You take a risk; you explore. To do so, we may need to resort to provocations – ideas that are deliberately illogical, which can still contain seedlings of fresh ideas. Putting on the green hat, you protect yourself from being called a clown talking nonsense.

Under the protection of the green hat, I want to suggest that we fire the sales force.

Speaking about provocations, de Bono also mentions the word “po.” He compares the word to the white flag: for example, if someone is carrying a white flag, no one will shoot him because it is against the rules. Likewise, if you use the word “po” before a sentence, no one can tell you that you’ve lost your mind because you’re under protection. “Po” can arise from a hypothesis, a possibility or even a poetry; in any case, it is a great green hat device:

Po cars should have square wheels.

Green hat ideas do not necessarily have to be illogical: you can take an idea that someone dismissed as negative under the black hat, and try to develop it. They can also be alternatives which you didn’t notice – after all, the first answer is not always the best one. In most cases, there is more than one answer. Why not leave it as a backup and look for more? You can always come back to it.

De Bono also emphasizes that when we tell someone to think under the green hat, we cannot demand input. We can only demand effort; we can demand the time to sit and think creatively. This may or may not lead to a result. But it’s the effort that matters.

The Blue Hat

Think of the blue sky above. Think of ‘overview.’ The blue hat is for thinking about thinking... The blue hat is for the organization of thinking. The blue hat is for process control.

The blue hat sets the agenda or the sequence of other hats’ use. It is not concerned with a subject; it is concerned with thinking. The blue color of the hat symbolizes detachment and being in control. It is typically worn by the chairman or the leader, because it’s what his role logically requires to do. In the process of a thinking session, other participants can make suggestions. At the end of it, the blue hat demands an outcome – a conclusion, a summary, or a decision.

The thinking process that is going on under the blue hat is formally structured and is very different from free-flowing thinking. When we think without any structure, our emotions, criticism, suggestions and so on get mixed, and it is pretty challenging to come to a constructive conclusion. A structure facilitates the whole process:

White hat thinking at this stage. Now we need some proposals. That means yellow hat thinking. Concrete suggestions please.

The author compares the blue hat thinking to computer software: it creates a program that has to be customized to each situation. A program needed to solve a problem will differ from a program that designs a boat. Similarly, a blue hat thinker decides in what order he needs to apply other hats. However, organizing the other hats is not the only function of the blue hat. It can also be used to assess priorities, or list constraints – in other words, to structure substeps within a larger process.

As de Bono says, a good thinker is a person who has an ability to focus. The blue hat thinking prevents us from drifting away. And a very useful technique to stay focused is to ask the correct question. The questions can be divided into two types: the first type is a fishing question (when you don’t know what the answer could be – it’s like putting a bait on a hook and waiting), and the second type is a shooting question (when the answer can be only yes or no). Carefully choosing a question, you can get the right answer much sooner.

The blue hat is also responsible for maintaining discipline. The person wearing it should control if participants make remarks in the context of a particular hat – this is why it is useful to identify the remarks from time to time.      

“The Six Thinking Hats” described by Edward de Bono is a simple and enjoyable method of thinking, widely used throughout the world – by teachers from New Zealand working with 5-year old children, by NASA and Shell, and many others. The advantages of it are obvious. The Six Thinking Hats method saves a lot of time since, instead of arguing, we just add more parallel ideas, moving in the same direction with our counterparts. It diminishes the impact of ego, which usually makes it more difficult to find a solution. Finally, it relieves us from enormous stress caused by trying to figure out what exactly is going on in our head. It may seem unusual, but it’s definitely worth trying. 

📚 Read other book summaries on management from Runn:

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