Thought, covert symbolic responses to stimuli that are either intrinsic (arising from within) or extrinsic (arising from the environment). Thought, or thinking, is considered to mediate between inner activity and external stimuli.
In everyday language, the word thinking covers several distinct psychological activities. It is sometimes a synonym for “tending to believe,” especially with less than full confidence (“I think that it will rain, but I am not sure”). At other times it denotes the degree of attentiveness (“I did it without thinking”) or whatever is in consciousness, especially if it refers to something outside the immediate environment (“It made me think of my grandmother”). Psychologists have concentrated on thinking as an intellectual exertion aimed at finding an answer to a question or the solution of a practical problem.
The psychology of thought processes concerns itself with activities similar to those usually attributed to the inventor, the mathematician, or the chess player, but psychologists have not settled on any single definition or characterization of thinking. For some it is a matter of modifying “cognitive structures” (i.e., perceptual representations of the world or parts of the world), while others regard it as internal problem-solving behaviour.
Yet another provisional conception of thinking applies the term to any sequence of covert symbolic responses (i.e., occurrences within the human organism that can serve to represent absent events). If such a sequence is aimed at the solution of a specific problem and fulfills the criteria for reasoning, it is called directed thinking. Reasoning is a process of piecing together the results of two or more distinct previous learning experiences to produce a new pattern of behaviour. Directed thinking contrasts with other symbolic sequences that have different functions, such as the simple recall (mnemonic thinking) of a chain of past events.
Historically, thinking was associated with conscious experiences, but, as the scientific study of behaviour (e.g., behaviourism) developed within psychology, the limitations of introspection as a source of data became apparent; thought processes have since been treated as intervening variables or constructs with properties that must be inferred from relations between two sets of observable events. These events are inputs (stimuli, present and past) and outputs (responses, including bodily movements and speech). For many psychologists such intervening variables serve as aids in making sense of the immensely complicated network of associations between stimulus conditions and responses, the analysis of which otherwise would be prohibitively cumbersome. Others are concerned, rather, with identifying cognitive (or mental) structures that consciously or unconsciously guide a human being’s observable behaviour. ...