Psychology finds its initial roots in the philosophy of the ancient Greeks, many of whom attempted to divide the conscious mind, defining things like morality and purpose. Though their studies were perhaps to esoteric and religion-centric to be considered even psuedoscience, it was questions like theirs that would eventually seek scientific answers through psychology. However, until the 19th century, psychology was considered to merely be a branch of philosophy.
The roots of change can be seen as early as 1550, where a document now known as the “Ebers papyrus” contained a short, semi-mystical description of clinical depression. Though fraught with pre-scientific spells and the like, this represents a definitive step toward modern psychological thought. Some forty years after this, German-born Rudolph Goclenius is believed to have coined the term “psychology” itself, combining the Greek word root for “soul” with a suffix meant to imply “study thereof.” That this “study of the soul” would someday be an area grappling entirely with non-divine issues is a rather ironic twist in history.
By 1879, things had changed significantly, as evidenced by the founding of Wilhelm Wundt’s founding of a laboratory for the express purpose of studying mental states and behavior. Barely 10 years later, in 1890, William James published his landmark work, Principles of Psychology, effectively setting the terms for psychological discussion for years to come. Wundt’s adherents went on to advance the cause of structuralism, examining the structure of mental processes, whilst James’ students lived by the creed of fundamentalism, breaking processes into their component parts. Though practices like introspection were prevalent at this point, these early psychologists showed a major departure from those of previous generations: no aspect of metaphysics or religion found its way into their analysis; their work was, for all intents and purposes, scientific. Also, the American Psychological Association was formed in 1892.
Another major player of the 1890s era was Sigmund Freud, who’s sexually-driven analysis of the so-called unconscious mind was at the core of his field, known as psychoanalysis. Working primarily for rich patients using questionable methods such as hypnotism and introspection, Freud nonetheless went on to have massive impact on the scientific community as a whole, and to this very day, psychoanalysis remains a viable approach to psychology.
Perhaps in response to the still lax laws of science practiced in some areas of psychology, behaviorism rose to popularity, championed by the likes of John B. Watson, Edward Thorndike, and B. F. Skinner. These men did away with notions of internal processes like belief and goals, instead believing that the root of all human action was in stimulus-response mechanisms initiated by environmental variables that then acted upon subconscious reflexes in the mind. In his 1913 paper, Psychology as the Behaviorist Views It, Watson went on to make statements such as that behaviorism “Is a purely objective experimental branch of natural science.” The statement that “The behaviorist. . . recognizes no dividing line between man and brute” is perhaps the branch’s most controversial, but it is also perhaps its most well defended.
From within behaviorism came conditioning models of human behavior which, aside from being remarkably successful, also were able to enhance the branch’s strength throughout much of the early part of the 20th century.
In many ways, 1957 was the final year of behaviorism’s undisputed reign as the most popular and accepted branch of psychology. In it, Noam Chomsky published a book known as Verbal Behavior which used the observation that children were able to create sentences outside the realm of what strictly behaviorist-based learning theories allowed them. Along with similarly timed by Albert Bandura, this book demonstrated the need for the study of long-forgotten internalized representations.
As a result, various new forms of psychology arose, and together with surviving aspects of the older schools of thought, these have gone on to define modern psychology as a varied and productive field. Some of these newer ways of thinking include the following.
Cognitive psychology was formed partially in response to the rise of computerized thinking, and certainly due to the relative fall of behaviorism, and it attempted to account for the previously ignored mental states and representations scientifically. Through the hard work and dedication of scientists like Charles Sherrington and Donald Hebb, as well as numerous studies into the functioning of brain-damaged individuals, cognitive science has further branched into neuropsychology and cognitive neuroscience. These schools of thought primarily seek to explain and quantify links between the brain and nervous system and human behavior, and utilize experimentation heavily.
Carl Jung went on to infuse traditional Freudian psychoanalysis with his own brand of spirituality, and went on to create a particularly popular branch of pseudoscience. This is another ironic twist, in that Freud himself believed religion to be no more than a mass delusion.
Also, humanists like Abraham Maslow and Carl Rogers, and the Gestalt theorist Fritz Perls have carved out unique sectors of psychology set up primarily around an almost existentialist and phenomenological view of psychology. Their views on a hierarchy of human needs, client-centered therapy, and human experience may well not be the most scientific, however, leading to a strange sort of full-circle motion in psychology.
These varied fields have each contributed to the vast array of psychological knowledge available today, and each continues to influence science as science still attempts to quantify and explain the inner workings of the human mind.