Difference between lateral and vertical thinking

Edward de Bono distinguishes two complementary ways of thinking. Vertical thinking develops a selected approach through connected steps. Lateral thinking changes the approach itself, deliberately exploring alternatives even when the current one seems adequate.

In de Bono’s model, the mind handles information by creating patterns — repeatable concepts, ideas, images, sequences of thought — and then perpetuates them. This pattern-making system has characteristic limitations. It is good at establishing concept patterns but not at restructuring them to bring them up to date. The sequence in which information arrives powerfully influences how it is arranged, and a workable arrangement may prevent us from considering better ones. A pattern that is useful and adequate can block the emergence of a far better one — a phenomenon of being “blocked by openness.” Established patterns can also create pseudo-problems, trap us within rigid frameworks, or prevent a more effective arrangement of information simply because they work well enough. Lateral thinking exists to compensate for these inherent disadvantages: it restructures old patterns, provokes new ones, and helps us make the best possible use of available information. Lateral and vertical thinking are complementary; skill in both is necessary, though de Bono argues that education has traditionally emphasised vertical thinking.

Vertical thinking is selective, lateral thinking is generative. Rightness is what matters in vertical thinking. Richness is what matters in lateral thinking. Vertical thinking selects a pathway by excluding others. Lateral thinking does not select but seeks to open up other pathways. With vertical thinking one selects the most promising approach to a problem, the best way of looking at a situation. With lateral thinking one generates as many alternative approaches as one can. One may look for different approaches until a promising one is found, but with lateral thinking one goes on generating alternatives even after finding a promising one. Vertical thinking tries to select the best approach; lateral thinking generates different approaches for the sake of generating them.

Vertical thinking moves only if there is a direction in which to move, lateral thinking moves in order to generate a direction. With vertical thinking one moves in a clearly defined direction towards the solution of a problem, using a definite approach or technique. With lateral thinking one moves for the sake of moving. One does not have to be moving towards something; one may be moving away from something. It is the movement or change that matters. With vertical thinking one designs an experiment to show a specific effect. With lateral thinking one designs an experiment to provide an opportunity to change one’s ideas. With vertical thinking one must always be moving usefully in some direction. With lateral thinking one may play around without any purpose or direction — with experiments, models, notation, ideas. The movement and change of lateral thinking is not an end in itself but a way of bringing about repatterning. De Bono expects the mind’s pattern-forming tendency to turn some of that movement into useful possibilities. The vertical thinker says, “I know what I am looking for.” The lateral thinker says, “I am looking but I won’t know what I am looking for until I have found it.”

Vertical thinking is sequential, lateral thinking can make jumps. With vertical thinking one moves forward one step at a time. Each step arises directly from the preceding step to which it is firmly connected. The soundness of a conclusion is proved by the soundness of the steps by which it was reached. With lateral thinking the steps do not have to be sequential. One may jump ahead to a new point and then fill in the gap afterwards. When one jumps right to the solution, the soundness of that solution does not depend on the soundness of the path by which it was reached. The solution may still make sense in its own right. It may also happen that once a particular point is reached, it becomes possible to construct a sound logical pathway back to the starting point — a pathway that could only have been constructed from the “wrong” end. One may need to be on top of a mountain in order to find the best way up.

Vertical thinking follows the most likely paths, lateral thinking explores the least likely. Lateral thinking can be deliberately perverse. With lateral thinking one tries to look at the least obvious approaches rather than the most likely ones. It is the willingness to explore the least likely pathways that is important, for often there can be no other reason for exploring such pathways. At the entrance to an unlikely pathway there is nothing to indicate that it is worth exploring, and yet it may lead to something useful. With vertical thinking one moves ahead along the widest pathway pointing in the right direction.

Beyond these contrasts, lateral thinking is both an attitude and a method of using information. The lateral thinking attitude regards any particular way of looking at things as useful but not unique or absolute. It acknowledges the usefulness of a pattern but instead of treating it as inevitable, sees it as only one way of putting things together. It challenges the assumption that a convenient pattern is the only possible pattern. The lateral thinking attitude involves a refusal to accept rigid patterns and a continual attempt to put things together in different ways. During lateral thinking, judgement is postponed so that alternatives have time to develop. One can be satisfied with the current pattern and still explore others; their usefulness can be assessed afterward. The method of lateral thinking uses information not for its own sake but for its effect. This way of using information involves looking forward, not backward: one is not interested in the reasons that lead up to and justify a piece of information, but in the effects that might follow its use. In vertical thinking, information is assembled into some structure, bridge, or pathway; the information becomes part of the line of development. In lateral thinking, information is used to alter the structure but not to become part of it — much like using a pin to jab someone and make them jump rather than to hold pieces of paper together. Lateral thinking is not stabilising but provocative. It has to be, in order to bring about repatterning. Because it is not possible to restructure a pattern by following its own lines of development, lateral thinking may be deliberately perverse. It may use irrelevant information, or it may involve suspending judgement and allowing an idea to develop instead of shutting it off by pronouncing it wrong.

The practical contexts that especially call for lateral thinking are description, problem solving, and design. These are situations where knowledge is readily available and the emphasis is on the best use of that knowledge, rather than on acquiring more of it. New ideas — whether new inventions, new ways of doing things, new ways of looking at things, new ways of organising things, new ways of presenting things, or new ideas about ideas — are constantly in demand. Vertical thinking is not much help in the deliberate generation of new ideas; lateral thinking is a more deliberate way of setting about it.

Developing skill in lateral thinking requires deliberate practice. It is not enough to appreciate it in the abstract or to regard it as something that only a few creative people use. Setting aside a definite period for teaching lateral thinking — one hour a week throughout education, for instance — is far more effective than trying to gently introduce its principles in the course of teaching some other subject. One uses the same basic techniques over and over again, changing the material but rehearsing the same process. It is the use of lateral thinking that counts, not knowledge of every technique. The best way to acquire skill is to become thoroughly familiar with a collection of tools that are all used to bring about the same effect. Once the lateral thinking attitude is acquired, one no longer has to keep it separate from vertical thinking. The two blend together; at one moment vertical thinking is used, and the next moment lateral thinking is used. Nevertheless, certain occasions — particularly description, problem solving, and design — call for the deliberate use of lateral thinking.

In this model, lateral thinking helps restructure familiar patterns by introducing unexpected information or changing the way a problem is described. Vertical thinking then helps develop and assess the possibilities. Deliberate disruption creates material to work with; it does not establish that the resulting idea will work.