Part of being an adult is dealing with the responsibility and hassle of bills. Insurance, mortgages, and vehicle financing add to the daily stresses you face at work. Yet without that car you're paying for, you probably couldn't even get to your office, and your daily life would be greatly restricted. The invention of the automobile, itself a combination of numerous innovations by many different inventors, has forever changed the way people travel. In general, inventions—especially those destined to have a lasting impact on people's lifestyles—undergo a complex process of development, during which the original concept evolves and gives rise to many different incarnations. The psychology of invention is an important aspect of human creativity.
The term "psychology of invention" was coined by Jacques Hadamard, who used it in his 1945 book Psychology of Invention in the Mathematical Field. Cognition, the act or process of knowing, had previously been associated with language. But Hadamard insisted that when solving mathematical problems, he did not perceive his thoughts in words, but rather in images. He surveyed 100 leading physicists of his day and they reported similar mental processes. Using this evidence, he outlined a four-step process of problem-solving: preparation, incubation, illumination, and verification.
Hadamard's book renewed interest in cognitive psychology. Cognitive psychology as it pertains to inventing is a relatively young field of study, a specialty which has only emerged in the last three or four decades. It investigates the internal mental processes of thought, such as visual processing, memory, problem solving, and language. Its framework, called the Circle of Thought, consists of five basic functions of thinking: describe, elaborate, decide, plan, and act.