History of Psychology
History of Psychology
Plato's (c. 428-347 B.C.) emphasis on individual differences is evidenced in his belief that humans differ in the powers they possess. Some are notable for intellectual abilities, others for their courage, and others for their motivation. Plato, who devoted his life to the study of ideas, argued that reason is the highest of human powers and that individuals so possessed should be the leaders of society. On the other hand, those possessed of great courage should serve as warriors. In his ideal world, which he called a republic, individual capacities would determine the role a person plays in society.
For Plato, the source of those individual differences is the human soul whose makeup is determined at birth. Galen (c. 129-199 A.D.), a Greek physician, was also interested in the differences among humans. Borrowing from some of the work of the physician Hippocrates, Galen proposed that behaviors were caused by an overabundance of a particular kind of bodily fluid. He decided that depressed people have too much "black bile", whereas apathetic people have too much "phlegm". These pronouncements about human behavior and ability were not the result of experimental investigations, nor were they derived by any kind of systematic observations. They were arrived at by the use of reason, logic, and common sense, a philosophical approach to knowledge known as rationalism.
Galen's views persisted until the sixteenth century. Although ultimately discredited, his theory is of historical importance because it illustrates a recognition of psychological differences among people, and it explains those differences in terms of natural, rather that supernatural, causes.
Gradually replacing the philosophy of Plato was a belief that knowledge should be acquired through observation and experimentation, a philosophy that marked the beginning of the scientific method. Psychology, as an experimental science, grew from both the post-Renaissance developments in philosophy and the development of physiological studies of the nervous system and sensory mechanisms.
A new world view emerged, initially due to the work of Galileo (1564-1642). Galileo conceived of the universe as being composed of matter in motion, where one object would come into contact with a second object, and cause a movement or change in the second object. This view of the world was known as mechanism, and it meant that by conceiving of the universe as a giant machine, lawful explanations of the universe would be possible. According to this view, the universe, like any machine, must operate in an orderly way. Thus, its operation can be understood by discovering the laws that govern it. This order and lawfulness meant that actions in the universe could be predicted by understanding the casual relationships within the world.
Because humans are part of the universe, could they also be viewed as machines? According to René Descartes (1596-1650), the answer was yes. Descartes extended the mechanistic view to human behavior, and viewed both the body and part of the mind as machines, capable of interacting with-and influencing-one another. This idea provided an excellent explanation for both involuntary (reflexive) and voluntary behavior. By adding human actions to the mechanistic world view, Descartes was arguing that human behavior is lawful and its causes can be understood.
Descartes was interested in the nature of the human mind and proposed that it consisted of two kinds of ideas: innate ideas, such as "self" and "God", and derived ideas, which are acquired through experience and reflection. A viewpoint opposing Descartes' doctrine of innate ideas was the philosophy of empiricism, which held that knowledge should be acquired by careful observation. The empiricists were a group of philosophers that spanned a period of over 200 years, beginning with John Locke (1632-1704). Locke rejected the concept of innate ideas, forcefully arguing that all ideas are derived from experience. Locke described how knowledge would be written on the mind, which could be represented as a blank slate. Thus, according to Locke and others, all knowledge is learned. Although not experimental in nature, their work dealt with many of the basic questions in human perception, learning, and thinking, by investigating the sensory mechanisms.
In the same time period, advances in physiology unlocked some of the mysteries of brain functions, and the manner in which the nervous system transmits information. Researchers discovered that specific regions of the brain have specific functions. Paul Broca (1824-1880) used the clinical autopsy method to examine the brains of individuals who had lost the ability to speak. Broca found localized damage, lesions, in the third convolution of the frontal lobes, an area believed to be responsible for production of speech. Later, researchers demonstrated that certain motor and perceptual functions could be produced from mild electrical stimulation to particular areas of animal brains.
Wilhelm Wundt (1832-1920) is generally honored as the founder of scientific psychology. Wundt wrote his first book on psychology, dealing with sensory perceptions, in 1862. It was based largely on his training as a physiologists and would be characteristic of much of his work. In 1879, Wundt founded the first research laboratory in psychology at the University of Leipzig.
The initial goal of psychology was to understand the nature of human consciousness. To understand this, Wundt used the method of introspection, in which a person experiences something and then describes the personal nature of the experience. This technique can be used quite rigorously when stimulus presentation are controlled, so that introspective accounts can be compared across many experiences. Researchers were to report their experiences in terms of specific sensations and feelings, which were then developed into the basic building blocks of the conscious mind. The main goal of Wundt's psychology was to first discover these building blocks, and then discover how they combined to form the more complex elements of mental processes.
The research in Wundt's lab consisted of studies in the fields of sensation and perception: investigating color vision and the passage of time, as well as research into other mental processes such as emotion. One famous study in Wundt's lab was in the field of reaction time. Wundt hypothesized that by measuring the difference between the speed of a simple mental event and a complex mental event, it was possible to calculate the amount of time mental processing required.
Other psychology laboratories soon emerged, including that of Herman Ebbinghaus (1850-1909), whose memory studies are still being referenced. These laboratories challenged many of Wundt's views on psychology, such as his insistence that consciousness could be broken into elemental parts and his reliance on introspection. One German branch of psychology that was opposed to Wundt's ideas was Gestalt psychology which originated with Max Wertheimer (1880-1943), Kurt Koffka (1886-1941), and Wolfgang Köhler (1887-1967). They argured with the atomistic approach to human consciousness, and instead claimed that "the whole is different from the sum of its parts." For instance, a picture with all of the color information inverted is still recognizable as having the same pattern, even though the elements comprising the picture are completely different in the two versions. Gestalt psychology made substantial contributions to the areas of perception and learning before many in the field moved from Germany to the United States during the mid-1930s. Even though Gestalt psychology never became part of the mainstream, it had a great influence on the beginnings of American psychology. Much of the modern work with Gestalt theories are now associated with the cognitive approach.
One of the representatives of Wundt's psychology that came to America was the British student E. B. Titchener (1867-1927). Titchener's psychology, which became known as structuralism, closely follows the atomistic portion of Wundt's psychology by studying the elemental structures of consciousness. However, instead of explaining them by hypothetical mental processes as Wundt had, Titchener focused on research that was purely descriptive. His books on experimental psychology (Titchener, 1901-1905) became very influential in the training of the first generation of American psychologists.
Other groups in America entirely broke away from the teachings of Wundt. Many of these groups used ideas developed by Charles Darwin (1809-1882) to formulate theories to explain variations between members of a species. Darwin's theory of evolution that linked humans with the rest of the animal kingdom began the idea of comparative psychology, and the idea of interpolating human behavior from the study of animals. Another important contribution by Darwin to the emerging American psychology was that of natural selection. Specifically, how the implication of the selection of characteristics that were most valuable to the organism could be used to examine the adaptive significance of consciousness.
Functionalism Under the influences of Darwin, many American psychologists began examining consciousness to understand how it helps the organism function, rather than its structures. One American psychologist who believed in the adaptive significance of consciousness was William James (1842-1910). James believed that mental processes had evolved in a similar manner to other traits, and his interest was in understanding the role consciousness played in helping an organism adapt to its environment. James's emphasis on understanding the functions of consciousness led to the founding of a new system of psychology known as functionalism, which is mainly an American system of psychology. Most of James's ideas were examined in The Principles of Psychology (1890), which is one of the most important works in the history of psychology.
Behaviorism The third type of psychology that evolved during this time period contested with both structuralism and functionalism. Behaviorism, as the new system was called, was revolutionary in both the nature of material it studied, as well as the methods used in study. The founder of this branch of psychology was John B. Watson (1878-1958) who believed that psychology would never fully develop until "it need no longer delude itself unto thinking that it is making mental states the object of observation." Watson called for a radical change in the focus of psychology: studying behavior instead of consciousness. Because consciousness was not directly observable, it was difficult to measure and therefore had no place in the domain of science. Behavior represented actions that were subject to direct observation, and psychology could then be based on discovering the causes of behavior and the investigation of relations between stimuli and response.
Watson also tried to minimize the importance of studying heredity that had been placed into the field of psychology by functionalism. He denied the existence of instints, or inherited traits. This viewpoint led him to decide that a person's achievements are limited solely by the restrictions placed by the environment on the person's abilities. This radical change gave psychology a means to improve the human condition in particular, and society in general, and made Watson a popular figure in American culture.
Watson's scientific psychology could not have an imprecise means of
experimentation, such as introspection, so Watson encouraged a number
of new techniques:
nallen@tjhsst.edu
