De Bono gives the example of an antelope immediately recognizing the presence of a lion and reacting quickly because it has been presensitized to react this way. However, this presensitization is only one way to think. The Six Hats method allows the brain to “maximize its sensitivity in different directions at different times” (1).

De Bono asserts that Western thought focuses on “what is,” as determined by analysis, judgment, and argument, because of the dominance of ideas put forth by three ancient Greek philosophers: Socrates, Plato, and Aristotle. De Bono argues that they did not focus on outcomes but on determining truth through various methods of reasoning. In contrast, de Bono’s method is focused on “what can be” (2), or finding a way forward.

The mind creates standard situations based on past events, but this system only works in a stable world. In a changing world, standard situations may no longer apply. This is why it is more important to “design our way forward” (3) instead of judging it forward. In addition, many cultures look at argument as aggressive and nonconstructive. This is why other cultures readily embrace the parallel thinking of the Six Hats method.

De Bono defines parallel thinking, the root of the Six Hats approach, as looking at a situation from different views and accepting all, no matter how contradictory. It may be necessary to later choose between the different positions, but if a choice can’t be made, the design has to cover both possibilities. When multiple people are looking at a situation, they all look in the same “direction” at the same time.

These directions are the hats of the author’s method. They are colored white, red, black, yellow, green, and blue. He chose hats as a metaphor because of the association between thinking and “thinking caps” and because a hat can symbolize a particular role, as it does in the phrase “putting on a different hat.” De Bono notes that the hats are directions, not descriptions or summaries of what has been said. They focus the users on particular ways of seeing an issue and are forward-looking.

Further defining the hats, de Bono says they do not describe categories of thinking; a person is not “a green hat person” (6). In fact, everyone is capable of looking in every direction. The author also cautions against assigning “hat” roles to individuals in a group. Rather, everyone applies their experience and intelligence to looking in the same direction at the same time. Those who miss showing off in an argument-style discussion can instead show off by seeing how many ideas they can put forward under the various hats.

The Six Hats method follows what de Bono regards as a Confucian approach rather than an analytical one. It directs people to respect others, or show “right behavior,” regardless of status or relationship. De Bono calls this approach “going straight to behavior” (8) because it doesn’t attempt to change the personality of any users. Nonetheless, the method does expect users to participate and follow the rules.

De Bono identifies the benefits of the method based on the results he has seen since the book was first published. He claims it is powerful because it uses the knowledge and experience of the whole group. It shortens meeting times by eliminating arguments. It removes ego from discussions, and it provides focus because users only do one thing at a time.

Each thinking hat has a color: White, red, black, yellow, green, blue. De Bono chose the colors for their symbolic associations. White is a neutral color, so the white hat deals with objective facts and figures. Red suggests anger, so the red hat gives an emotional view., Black is somber and serious; this hat is cautious, pointing out the weaknesses in an idea.

Yellow is sunny and positive, so the yellow hat deals with hopeful, positive thinking. Green suggests nature and growth, so the green hat deals with creativity and new ideas. Finally, blue is cool and represents the color of the sky, which is above all else. The blue hat deals with control, organizing the thinking process, and using the other hats.

The hats are always referred to by their color, not their function, because colors don’t have emotionally charged associations. For example, it is easier to ask someone to take off their black hat than to ask them to stop being cautious.

The hats can be used in two basic ways: Singly, to request a type of thinking, or in a sequence, to explore an issue or solve a problem. In single use, the hat can generate fresh options during a conversation or discussion, as in the statement, “We need some green hat thinking here” (16).

Specific hat colors have single-use benefits. The red hat can allow a manager to ask for employees’ feelings on a matter, while the yellow hat encourages people to look for values. It’s often harder to find benefits to an idea than dangers, so the yellow hat is especially useful for finding value. The white hat provides a chance to separate information from judgment.

When the hats are used sequentially it isn’t necessary to employ every hat; the sequence could be made up of two to six hats. There are two broad types of sequencing, evolving and preset. With the evolving sequence, a person or facilitator chooses the first hat and someone else chooses the next. Only experienced users of the method should employ the evolving sequence, for two reasons: The choice of which hat to use can lead to argument, and the choice can be used to manipulate a desired outcome.

The preset sequence is set up under the blue hat as a meeting begins. Only the group leader can indicate a change of hat, and each change should take a short time, such as one minute per person present for each hat. The time can be extended if genuine ideas are being generated. The red hat idiom, in particular, should take only a short time. Facilitators can ask individuals to think on their own before discussing the thoughts they have generated, and they can call on individuals specifically for their thoughts.

Any sequence that works for the leader can be used, but the sequence should also end with the blue hat. The first one indicates issues such as defining the situation and the desired outcome, and the final one summarizes the outcome that has been identified and considers the design, solution, and next steps to achieve that outcome.

If there are strong feelings on a subject, the red hat can immediately follow the first blue hat, letting people get their feelings into the open right away. It can also follow the final blue hat as a reflection on the thinking process, answering questions such as, “Are we happy with the outcome?” (21). In an assessment situation, de Bono suggests putting the yellow hat before the black hat, since the yellow mode will determine whether or not there is any merit to an idea.