Behaviorism was the dominant paradigm in American psychology throughout the first half of the 20th century. However, the modern field of psychology largely came to be dominated by cognitive psychology. Noam Chomsky’s 1959 review of B. F. Skinner’s Verbal Behavior challenged the behaviorist approaches to studies of behavior and language dominant at the time and contributed to the cognitive revolution in psychology. Chomsky was highly critical of what he considered arbitrary notions of ‘stimulus’, ‘response’ and ‘reinforcement’ which Skinner borrowed from animal experiments in the laboratory. Chomsky argued that Skinner’s notions could only be applied to complex human behavior, such as language acquisition, in a vague and superficial manner. Chomsky emphasized that research and analysis must not ignore the contribution of the child in the acquisition of language and proposed that humans are born with a natural ability to acquire language. Work most associated with psychologist Albert Bandura, who initiated and studied social learning theory, showed that children could learn aggression from a role model through observational learning, without any change in overt behavior, and so must be accounted for by internal processes.
With the rise of computer science and artificial intelligence, analogies were drawn between information processing by humans and information processing by machines. This, combined with the assumptions that mental representations exist and that mental states and operations could be inferred through scientific experimentation in the laboratory, led to the rise of cognitivism as a popular model of the mind. Research in cognition was also backed by the aim to gain a better understanding of weapons operation since World War II.
Cognitive psychology differs from other psychological perspectives in two key ways. First, it accepts the use of the scientific method, and generally rejects introspection as a method of investigation, unlike symbol-driven approaches such as Freudian psychodynamics. Second, it explicitly acknowledges the existence of internal mental states—such as belief, desire and motivation—whereas behaviorism does not. In fact, like Freud and depth psychologists, cognitive psychologists are even interested in unconscious phenomena, including repression; but cognitive psychologists prefer to explore these phenomena in terms of operationally-defined components, such as subliminal processing and implicit memory, that are amenable to experimental investigation. Moreover, cognitive psychologists have questioned the very existence of some of these components. For example, American psychologist Elizabeth Loftus has used empirical methods to demonstrate ways in which apparent memories can be brought to light via fabrication rather than through the elimination of repression.
Preceding the cognitive revolution by several decades, Hermann Ebbinghaus had pioneered the experimental study of memory, arguing that higher mental processes are not hidden from view, but instead could be studied using experimentation. Links between psychological activity and brain and nervous system function also became understood, partly due to the experimental work of people such as English neuroscientist Charles Sherrington and Canadian psychologist Donald Hebb, and partly due to studies of people with brain injury. These mind-body links are explored at length by cognitive neuropsychologists. With the development of technologies for measuring brain function, neuropsychology and cognitive neuroscience have become increasingly active areas of contemporary psychology. Cognitive psychology has been subsumed along with other disciplines, such as philosophy of mind, computer science, and neuroscience, under the umbrella discipline of cognitive science.
