With the Six Hats method, the emphasis is on ‘what can be’ rather than just on ‘what is, and on how we design a way forward – not on who is right and who is wrong.

That is why the Six Hats method is essential. It allows the brain to maximize its sensitivity in different directions at different times. It is simply not possible to have that maximum sensitisation in different directions all at the same time. We need to be thinking about ‘what can be, not just about ‘what is.

The essence of parallel thinking is that at any moment everyone is looking in the same direction – but the direction can be changed. An explorer might be asked to look north or to look east. Those are standard direction labels. So we need some direction labels for thinking. What are the different directions in which thinkers can be invited to look? This is where the hats come in. In many cultures, there is already a strong association between thinking and ‘thinking hats’ or ‘thinking caps’. The value of a hat as a symbol is that it indicates a role. People are said to be wearing a certain hat. Another advantage is that a hat can be put on or taken off with ease. A hat is also visible to everyone around. For those reasons, I chose hats as the symbols for the directions of thinking. Although physical hats are sometimes used, the hats are usually imaginary. Posters of the hats on the walls of meeting rooms often are used, however, as a reminder of the directions. Six coloured hats are corresponding to the six directions of thinking: white, red, black, yellow, green, blue. 

It is very important to note that the hats are directions and not descriptions of what has happened. It is not a matter of everyone saying what they like and then the hats being used to describe what has been said. It is a matter of setting out to think in that direction. ‘Let’s have some white hat thinking here’ means a deliberate focus on information. Everyone now tries to think of available information, information that is needed, questions to be asked, other ways of getting information, and so on. ‘I want your red hat on this is a specific request for feelings, intuition and emotions on a particular issue. ‘That is good black hat thinking; now let us switch to some yellow hat thinking …’ In this case, the term black hat describes thinking that seems to be cautious and seems to point out possible difficulties, but the main intention is to ask for a switch to the yellow hat direction (benefits, values, and so forth). It is extremely important to appreciate the difference between description and direction. A description is concerned with what has happened. A direction is concerned with what is about to happen. ‘I want you to look to the east’ is very different from ‘You have been looking to the east.’ ‘I want you to cook some scrambled eggs’ is very different from ‘I see that you have cooked some scrambled eggs.’ 

It is possible to create tests to determine whether a person is type A or type B, or any similar descriptive discriminations. Psychologists do that all the time. The difficulty is that once people have been put into ‘boxes’ they tend to stay there. Again, that is an example of ‘what is’ instead of ‘what can be’. In a race, a thin man would usually beat a fat man (‘what is’). But if the fat man learns to ride a bicycle, then the fat man will beat the thin man (‘what can be’). There is a huge temptation to use hats to describe and categorise people, such as ‘she is black hat’ or ‘he is a green-hat person’. That temptation must be resisted. The hats are not descriptions of people but modes of behaviour. Some people may indeed be permanently cautious and inclined to look for dangers. Indeed, some people might always be bubbling with ideas and others might be better at focusing on facts. People may prefer one mode to another. People might be better at one mode than another. Nevertheless, hats are not categories of people. If you drive a car with manual gears, you use all the gears. In the engine of your car, all the cylinders are firing. The hats are directions of thinking. Every person must be able, and skilled, to look in all directions. For those reasons the use of hats as labels is dangerous because it destroys the whole point of the system, which is that everyone can look in every direction.

When people tell me that they have been using the Six Hats method, I often ask how they have been using it, and discover that sometimes they have been using it incorrectly. In a meeting, someone has been chosen as the black hat thinker, someone else as the white hat thinker, and so on. The people then keep those roles for the whole meeting. That is almost exactly the opposite of how the system should be used. The whole point of parallel thinking is that the experience and intelligence of everyone should be used in each direction. So everyone present wears the black hat at the appointed time. Everyone present wears the white hat at another time. That is parallel thinking and makes the fullest use of everyone’s intelligence and experience.

Many people tell me that they enjoy arguments because they can show off how clever they are. They can win arguments and demolish opponents. None of that is very constructive but there may be a human need to show off. Thus showing off is not excluded from parallel thinking and the Six Hats method. A thinker now shows off by showing how many considerations he or she can put forward under the yellow hat, how many under the black hat, and so forth. You show off by performing well as a thinker. You show off by performing better as a thinker than others in the meeting. The difference is that this type of showing off is constructive. The ego is no longer tied to being right. 

By going straight to behaviour, the Six Hats method is much more acceptable and effective and quick than methods that set out to change personalities. The ‘game’ aspect of the Six Hats is very important. If a game is being played, then anyone who does not obey the rules of the game is considered uncooperative. If there is a switch from the black hat (caution) to the yellow hat (possible benefits) and a person continues to lay out the potential dangers, then that person is seen to be refusing to play the game. Getting people to ‘play the game’ is a very powerful form of changing behaviour.

With the Six Hats method, we try to do only one thing at a time. There is a time when we look for danger (black hat). There is a time when we seek new ideas (green hat). There is a time when we focus on information (white hat). We do not try to do everything at the same time. People do not choose argument because it is the preferred method. They simply do not know any other way. The Six Hats provides another way.

The colour of each hat is also related to its function. If you remember the colour and the associations of each hat, remembering the function of the hat will then follow.

White Hat white is neutral and objective. The white hat is concerned with objective facts and figures. 

Red Hat: Red suggests anger (seeing red), rage and emotions. The red hat gives an emotional view. 

Black Hat: Black is sombre and serious. The black hat is cautious. It points out the weaknesses in an idea. 

Yellow Hat: Yellow is sunny and positive. The yellow hat is optimistic and covers hope and positive thinking. 

Green Hat: Green is grass, vegetation and abundant, fertile growth. The green hat indicates creativity and new ideas. 

Blue Hat: Blue is cool, and it is also the colour of the sky, which is above everything else. The blue hat is concerned with control, the organisation of the thinking process and the use of the other hats. 

In practice, the hats are always referred to by their colour and never by their function. There is a good reason for this. If you ask someone to give his or her emotional reaction to something, you are unlikely to get an honest answer because people think it is wrong to be emotional. But the term red hat is neutral. You can ask someone to ‘take off the black hat for a moment more easily than you can ask that person to stop being cautious. The neutrality of the colours allows the hats to be used without embarrassment. Thinking becomes a game with defined rules rather than a matter of exhortation and condemnation. The hats are referred to directly: … I want you to take off your black hat. … For a few minutes let us all put on our red thinking hats. … That’s fine for yellow hat thinking. Now let’s have the white hat.

There are two basic ways to use hats. The hats can be used singly to request a type of thinking. Or, the hats can be used in a sequence to explore a subject or solve a problem.

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.

White hat thinking is a discipline and a direction. The thinker strives to be more neutral and more objective in the presentation of information. You can be asked to put on the white thinking hat or you can ask someone to put it on. You can also choose to put it on or to take it off. The white (absence of colour) indicates neutrality.

Wearing the red hat allows the thinker to say: ‘This is how I feel about the matter.’ The red hat legitimises emotions and feelings as an important part of thinking. The red hat makes feelings visible so that they can become part of the thinking map and also part of the value system that chooses the route on the map.

The red hat covers two broad types of feeling. First, there are the ordinary emotions such as fear and dislike to the more subtle ones such as suspicion. Second, there are the complex judgements that go into such types of feeling as a hunch, intuition, sense, taste, aesthetic feeling and other not visibly justified types of feeling. Where an opinion has a large measure of this type of feeling, it can also fit under the red hat.

Black hat thinking is concerned with caution. At some stage, we need to consider risks, dangers, obstacles, potential problems and the downside of a suggestion. It would be extremely foolish to proceed with any suggestion unless full consideration has been given to the caution aspect. The black hat is about being careful. The black hat seeks to avoid dangers and difficulties. The black hat points out matters that need attention because they may be weak or harmful. The black hat draws us to matters that need our attention. The black hat can be used as part of the assessment: should we proceed with this suggestion? The black hat is used in the design process: what are the weaknesses that we need to overcome? The black hat seeks to lay out the risks and potential problems in the future: what may go wrong if we implement this suggestion?

Black hat thinking can be abused and overused if it is the only mode of thinking. This abuse in no way diminishes the value of the black hat, just as the dangerous and reckless driving of a car doesn’t mean that cars are dangerous.

Yellow hat thinking is positive and constructive. The yellow colour symbolises sunshine, brightness and optimism. Yellow hat thinking is concerned with a positive assessment, just as black hat thinking is concerned with a negative assessment. Yellow hat thinking covers a positive spectrum ranging from the logical and practical at one end to dreams, visions and hopes at the other end.

Yellow hat thinking is constructive and generative. From the yellow hat, thinking come concrete proposals and suggestions. Yellow hat thinking is concerned with transparency and with making things happen. Effectiveness is the aim of yellow hat constructive thinking. Yellow hat thinking can be speculative and opportunity seeking. Yellow hat thinking also permits visions and dreams. Yellow hat thinking is not concerned with mere positive euphoria (red hat) nor directly with creating new ideas (green hat).

The green hat is for creative thinking. The person who puts on the green hat is going to use the idioms of creative thinking. Those around are required to treat the output as a creative output. Ideally, both thinker and listener should be wearing green hats. The green colour symbolises fertility, growth and the value of seeds. The search for alternatives is a fundamental aspect of green hat thinking. There is a need to go beyond the known and the obvious and the satisfactory. The green hat thinker uses the creative pause to consider, at any point, whether there might be alternative ideas There need be no reason for this pause.

Lateral thinking is a set of attitudes, idioms and techniques (including movement, provocation) for cutting across patterns in a self-organising asymmetric patterning system. It is used to generate new concepts and perceptions.

The blue hat is the control hat. The blue hat thinker organizes the thinking itself. Blue hat thinking is thinking about the thinking needed to explore the subject. The blue hat thinker is like the conductor of the orchestra. The blue hat thinker calls for the use of the other hats.

Even when the specific blue hat thinking role is assigned to one person, it is still open to anyone to offer blue hat comments and suggestions.

In practice, one of the most striking things about the use of the Six Hats method is that decisions seem to make themselves. When you come to the final blue hat, the decision is often obvious to everyone present. This seems hard to believe in theory but happens very often in practice.

It is not surprising that with the Six Hats method the decision seems to make itself. After all, when we make decisions on our own, we go through more or less the same process (pros, cons, feelings, facts). The Six Hats method does all that very thoroughly. So what was hitherto carried out in an individual's mind is now done systematically and in the open?

Just as in any other decision-making process, the final decision may be difficult or even impossible to make. It may require balancing two conflicting values. It may depend on speculation about the future - and there is no way of removing the uncertainty about the future. At this point, there is a need to design a way forward that may cover both choices. If that is not possible and a decision still has to be made, then a red hat decision is made.

In the end, all decisions are really 'red hat'. We layout the factors but the final decision is emotional.

The biggest enemy of thinking is complexity, for that leads to confusion. When thinking is clear and simple, it becomes more enjoyable and more effective. The Six Thinking Hats concept is very simple to understand. It is also very simple to use.

There are two main purposes to the Six Thinking Hats concept. The first purpose is to simplify thinking by allowing a thinker to deal with one thing at a time. Instead of having to take care of emotions, logic, information, hope and creativity all at the same time, the thinker can deal with them separately. Instead of using logic to support a half-disguised emotion, the thinker can bring the emotion to the surface with the red thinking that without any need to justify it. The black thinking hat can then deal with the logic aspect.

The second main purpose of the Six Thinking Hats concept is to allow a switch in thinking. If a person at a meeting has been persistently negative, that person can be asked to take off the black thinking hat. This signals to the person that he or she is being persistently negative. The person may also be asked to put on the yellow thinking hat. That is a direct request to be positive. In this way, the six hats provide an idiom that is definitely without being offensive.

What is most important is that the idiom does not threaten a person's ego or personality. By turning it into role-playing or even a game, the concept of the hats makes it possible to request certain types of thinking. The hats become a sort of shorthand of instruction.