Proc. NatL Acad. Sci. USA Vol. 80, pp. 4569-4571, July 1983 Psychology Discovery, invention, and development: Human creative thinking* HERBERT A. SIMON Department of Psychology, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 Contributed by Herbert A. Simon, August 24, 1982 The subject of this paper is a singularly appropriate one for this and application. In particular, the development of products from journal. We are all experts on the topic of scientific discovery, basic discoveries takes place in a complex social and economic invention, and development. Members are elected to the Na- environment, in which both motivations and definitions of the tional Academy of Sciences because they have been adjudged problem differ very much from those in the environments where to have done some creative thinking that led to one or more basic discoveries typically occur. On the other side, I am going significant discoveries, inventions, or applications of scientific to emphasize the communalities of process-and to argue, in ideas. fact, that while discovery and development usually address dif- But the fact that a person sometimes does creative things does ferent substantive problems, the psychological processes of not mean that he understands the creative process. To imagine problem solution are quite similar. that a scientist can give a full scientific account of his own thought Let me begin by defining creativity in a pragmatic way. From processes is no more reasonable than putting a Geiger counter time to time, human beings arrive at ideas that are judged by on the podium at an American Physical Society meeting and their fellows to be both novel and valuable. The values dis- expecting it to deliver a lecture on the theory of radiation. In cerned in these new ideas may be intellectual, esthetic, prac- building a theory of scientific discovery or invention, a sci- tical, or what not. It does not matter. A psychological theory of entist's behaviors are the data-the phenomena we seek to ex- creativity (or discovery or invention) would account for the pro- plain-not the direct source of theory. cesses that are involved in bringing about such novel and val- Much of what goes on when we are thinking is inaccessible uable products. Of course, we should not beg the question: to our conscious awareness. We use such terms as "judge- whether creativity is a unitary thing or whether quite different ment, "intuition," and "creative insight" to name and label processes are involved in creative production in different do- those phenomena that occur without awareness. But labels are mains is itself an empirical question, to be decided on the basis not explanations; contrary to the view of Moliere's physician, of evidence. opium's sleep-inducing power is not explained by attributing to I will not try to survey the whole literature on creativity. It it a dormitive property. draws partly on historical, biographical, and autobiographical Many scientists and philosophers have doubted whether a accounts of discovery, on systematic surveys of creative (and scientific explanation of discovery is possible or whether there uncreative) persons, on a limited number of laboratory studies is even something describable as a method of discovery. Ein- aimed at eliciting creative behavior or comparing creative with stein himself is quoted as saying, "There is no logical path lead- noncreative styles of problem solving, and a number of recent ing to [scientific] laws. They can only be reached by intuition, attempts to simulate creative behavior with computer pro- based upon something like an intellectual love [Einfuehlung] of grams. At the phenomenological level, the level of observable the objects of experience." If Einstein meant by "logical path" events, there is great consistency among all the findings of this a deductive route to discovery, he was surely right. If he meant research, whatever its methods. I can sum up these findings in to say that there is not method in the madness of discovery, we a few generalizations. might question-and investigate empirically-whether his pes- What chiefly distinguishes creative thinking from more simism was justified. mundane forms are (i) willingness to accept vaguely defined The fact that many books and articles have been written on problem statements and gradually to structure them, (ii) con- the subjects of invention, discovery, and creativity, suggests tinuing preoccupation with problems over considerable periods that we believe that at least some significant aspects of these of time, and (iii) extensive background knowledge in relevant processes are amenable to investigation and description. Until and potentially relevant areas. Not all of these conditions-tol- recent times, most of our knowledge about them has derived erance of ambiguity, persistence, and knowledge-are satisfied from the experience and observations of thoughtful practition- in all cases of discovery, but their presence has been observed ers. In this case, the Geiger counter does indeed have some- and commented on too many times to suppose that their as- thing to say about the theory of radiation. But creative pro- sociation with success in discovery is accidental. None of these cesses are also now the objects of direct scientific investigation. conditions is very surprising; they all have a strong motivational In the past dozen years, some psychologists have sought to build component, and they satisfy our sense of justice-the virtues and test theories about the processes, both conscious and un- of patience, persistence, and diligence are likely to be re- conscious, that go on in the human brain when discovery and warded, even though there may be, as in gold mining, a large invention are taking place. Here, I am going to say a little about chance element in who wins the reward. The virtues only allow this psychological research, but mainly, I am going to consider you to buy a ticket in the lottery, and some tickets, as in all lot- what we know about these matters from the information that teries, pay off and some do not. is available to us more directly in our practice of science and engineering. Insight-based on recognition Processes of scientific discovery However, something seems to be left out of this picture. It seems Much can be said about the differences in process at the two * Presented at the annual meeting of the National Academy of Sciences, ends of the continuum from basic discoveries to development Apr. 26, 1982, Washington, D.C. 4569 Downloaded by guest on October 1, 2021 4570 Psychology: Simon Proc. Natl. Acad. Sci. USA 80 (1983) to deny the more romantic view of discovery that speaks of sophisticated, systematic algorithms for solution do not exist. In "insight" and "intuition" and the "creative moment." In an such ill-structured problem domains, problem-solving methods opinion he once wrote, Justice Learned Hand introduced into cannot be closely attuned to the characteristics of the problem our patent law the requirement that evidence of a "flash of ge- environment-such tuning requires a great deal to be known nius" was required to make an invention patentable-thereby about that environment. If we are given a linear algebraic equa- leaving a generation of patent attorneys with the desperate tion in one variable to solve, we simply apply a well-worn and problem of making such flashes visible. overlearned algorithm to solve it. Ingenuity is required only There seems to be no doubt, however, that the final step of when such an algorithm is not known to us. discovery is often a sudden event and sometimes an unexpected Hence, we may predict that persons tackling problems whose and surprising one to the inventor, who can give little account solution will have marks of novelty and require creativity will of the process that arrived at it. Often, the final step was pre- use very general methods that do not rely on specific knowl- ceded by a period of "incubation" during which the discoverer edge about the problem domain. Such methods, on the other was ostensibly preoccupied with other matters. Such events must hand, are likely to be highly inefficient; all that commends them also receive an explanation in a theory of creativity. They seem is that no better ones are available. somewhat less inscrutable when we reflect that (i) conscious Research using computer programming languages to design awareness is not an invariable property of mental processes and problem solvers has uncovered a number of such methods, which (ii) the theory is to account for the entire process and not simply are nowadays usually called "weak methods." An example of a the final step. In particular, it is typical of the act of recognition weak method is generate-and-test, which consists simply in de- in humans that, when we recognize a familiar pattern (a human vising possible solutions and then testing each one to see whether face or a beetle that is familiar from our scientific studies), we it satisfies the solution conditions of the problem-essentially are unable to report reliably what cues in the stimulus were trial-and-error search. A somewhat more powerful weak method, essential or instrumental to the recognition. It is notorious, for which requires for its application only a little more knowledge example, that the characteristics recorded in taxonomic keys about the problem domain, is means-ends analysis. In this (many determinable only under the microscope) are not at all method, a present situation is compared with a goal situation the characteristics that an experienced taxonomist uses for im- and one or more differences between them are detected. When mediate (and often quite reliable) recognition of species with a difference is noted, it may (by recognition) call forth from which he is highly familiar. memory an operator that is relevant to reducing differences of this kind.