What is the history of psychology?
Psychology can be assessed from points of view that regard it as a folk, cultural, or religious process; as a philosophical approach; as a scientific method; as an academic discipline; or as a set of postmodern assumptions.
From the folk process point of view, peoples have formed their own cultures and religions from the beginning of human history. These different cultures and religions have unique values and norms within which the person is considered and evaluated. Out of these norms come the everyday beliefs and expectations that members of the group will hold about themselves, other people, and the world. Thus, in every culture there is an implicit theory of psychology. Since this process is always operative, it has always been a factor in how specific thinkers such as philosophers, scientists, and psychologists, as well as laypeople, have been able to think about the human person. The folk process remains an especially important factor in some areas of psychology, such as humanistic psychology and clinical psychology.
Philosophy began to emerge about the year 600 BCE. At that time, Thales, a Greek thinker, began to consider systematically the nature of the world. His view that the world’s basic element is water demanded that the philosopher give up the folk process, or “common sense,” and argue for a conclusion based on rational premises. This new way of thinking led to a much broader set of possibilities in the understanding of the world and the human being. In terms of psychology, philosophers would concentrate on topics such as the relationship between the mind and the body and the process of acquiring knowledge, especially about what is outside the body. In the last decade of the twentieth century, cognitive psychology was strongly influenced by philosophic thinking.
By the end of the Middle Ages and the beginning of the Renaissance, another way of thinking and solving problems began to emerge. As a result of dissatisfaction with both religious and philosophic answers to understanding the world and its place in the cosmos, as well as knowledge about the nature of the human being, a process of systematic and repeated observation and rigorous thinking began to emerge. This new process, which has been labeled a part of modern thinking, has become the scientific method, requiring another separation from the folk process. For instance, when the Polish astronomer Nicolaus Copernicus and the Italian mathematician and astronomer Galileo Galilei argued from their observations that the earth revolved around the sun rather than the opposite, “common-sense” view, they offended both religious authorities and philosophers, but they opened the door to a new way of solving problems and understanding the world and human beings. This new way was named science.
Thanks to both philosophy and science, by the middle to end of the nineteenth century various scholarly areas had emerged, each with a unique use of methodology and subject matter. One of these disciplines was psychology. In 1879, Wilhelm Wundt, a German philosopher and physiologist, set up what is generally considered the first laboratory in experimental psychology. From that point, psychology began to be recognized as a discipline by scholars in the Western world.
Through an interaction with disciplines such as anthropology and linguistics, which were thriving on relativistic assumptions, and a philosophy of language that limited meaning to the particular and situational case, a psychological point of view developed in the mid- to late twentieth century called social constructionism. Although promoted by those who identify with the discipline of psychology, social constructionism is at odds with the assumptions of the modern period, including many of those that go with science, and is, therefore, labeled postmodern. Such an approach seeks only to describe and interpret rather than to explain, as is the aim in science. Parallel developments such as deconstruction in the field of literary criticism were taking place at the same time.
Over the years, philosophers asked questions about the world and how humans come to have knowledge of it, provided assumptions that would limit or promote certain kinds of explanations, and attempted to summarize the knowledge that was available to an educated person.
Those thinkers who considered the nature of reality and the world between the years ca. 624 to 370 BCE were called pre-Socratics. One of them, Heraclitus, opposed Thales’s idea of water as the basic element with his idea that fire was the basic element, and therefore the world and everything in it was in a state of flux and constant change. Empedocles went a step further to propose that there were four basic elements: earth, air, fire, and water. This scheme, when applied by physicians such as the Greek Hippocrates and the Greco-Roman Galen led to the notion of the four humors and a prototheory of personality that has been influential for almost two thousand years.
From his understanding of the thinking of Socrates and Pythagoras, Plato constructed a systematic view of the human as a dualistic creature having a body that is material and a soul that is spiritual. This doctrine had significant consequences for religion, for philosophy, and for psychology. Plato also saw knowledge as acquired by the soul through the process of recollection of the form, which exists in an ideal and abstract state. Plato’s student Aristotle systematized the study of logic, promoted the use of observation as a means of acquiring knowledge, and presented a different view of the human as one whose senses were reliable sources of information and whose soul, while capable of reasoning, was the form that kept the body (and the person) in existence.
The philosophers who came during the medieval period generally split into two camps: those who followed Plato and those who followed Aristotle. Just prior to the medieval period, Saint Augustine, bishop of Hippo (now part of Algeria), had combined Neoplatonism, Christianity, and Stoicism (to the extent of believing that following the natural law was virtuous). The Neoaristotelian tradition was typified by Thomas Aquinas, an Italian Dominican priest, who integrated Aristotelian thought with Christianity and who promoted the use of reason in the obtaining of knowledge. Although not anticipated by Thomas, this Aquinas point of view would ease the way for what would become scientific thinking.
René Descartes, a French Renaissance philosopher, created a dualistic system called interactionism, where the soul, which was spiritual, interacted with the body, which was material. Both the notion of interaction and its site, the pineal gland, were so open to debate that the theory led to two different traditions: a rationalist tradition and an empiricist tradition. The rationalist tradition was led by German thinkers such as Gottfried Wilhelm Leibniz, who was also an inventor of the calculus; Immanuel Kant, who taught that the mind had an innate categorizing ability; and Johann Friedrich Herbart, who held that, if expressed in mathematical terms, psychology could become a science. All the rationalists opted for the notion of “an active mind,” and Herbart’s thinking was very influential for those, such as Wundt, who would view psychology as a scientific discipline. The empiricist tradition was stronger in France and England. Several decisive representatives of empiricism were Englishmen John Locke, David Hume, and John Stuart Mill. Empiricism postulated that all knowledge came through the senses and that the ideas that made up the mind were structured on the percepts of the senses. Eventually, in Mill’s thinking, the ideas of the mind were held together through the laws of association.
Another tradition developed past the midpoint of this period was positivism. Positivism, as developed by Frenchman August Compte, argued that the only knowledge that one can be sure of is information that is publicly observable. This would strongly influence both the subject matter and the methodology of science in general and psychology in particular.
In the beginning of the twentieth century, Englishman Bertrand Russell introduced symbolic logic, and his student Ludwig Wittgenstein created a philosophy of language. Both of these developments were necessary precursors of the late twentieth century interest in the nature of mind, in which many disciplines came together to form cognitive science. Wittgenstein’s work would open the door for social constructionism.
The development of the scientific method was only one of the factors that was associated with the change from the Middle Ages to the Renaissance. Developments in anatomy, physiology, astronomy, and other fields from the middle of the sixteenth century to the beginning of the twentieth century have had a major impact on the understanding of science and have paved the way for psychology as a science. The work of Copernicus and Galileo, in freeing astronomy from folk and religious belief, was a start. In the field of anatomy Flemish scientist Andreas Vesalius published in 1543 the first accurate woodcuts showing the anatomy of the human body. This was a decisive break with the tradition of Galen. By 1628, Englishman William Harvey had described accurately the circulation of blood.
In the meantime, Englishman Francis Bacon, a contemporary of Galileo, offered a view of science that favored inductive reasoning on the basis of a series of observations. This was another break with the tradition of relying on the classical authorities. In 1687, the Principia was published by Englishman Isaac Newton, who laid the foundation for the calculus, enhanced the understanding of color and light, grasped the notion of universal gravitation, and produced laws (natural law) of planetary motion.
Soon Swiss mathematicians, members of the Bernoulli family and Leonhard Euler, were refining the differential and integral calculus that was invented independently of Newton by the philosopher Leibniz.
In 1751, a Scot, Robert Whytt, working on frogs, noted the importance of the spinal cord for reflex action. Localization of function in the nervous system was beginning.
By 1754, Swedish botanist Carolus Linnaeus had produced a system of classification for plants, animals, and minerals that made observation and discussion in science simpler.
German anatomist Franz Gall maintained that “faculties” of the brain were discernible by observing the contours of the skull: Phrenology was another step in localization but a false one that violated scientific axioms. It spread rapidly, especially in the United States, as a form of folk psychology and diagnosis.
In 1795, an assistant at the Royal Observatory in Greenwich, England, was found to be recording times of stellar transit consistently later than his supervisor. German astronomer Friedrich Wilhelm Bessel recognized that this was involuntary and might be calibrated as a personal equation. This recognition of reaction time foreshadowed many studies in the laboratories of psychology.
Italian physician and physicist Luigi Galvani in 1791 stimulated movement in a frog’s leg with electricity, demonstrating that electrical stimulation had a role in neural research. Englishman Charles Bell, in 1811, and Frenchman François Magendi, in 1822, demonstrated differential functions of the dorsal (sensory) and ventral (motor) roots of the spinal cord. Again, localization of function was promoted. In 1824–1825, Pierre Flourens introduced the technique of ablation studies for brain tissue.
The field of physiology came together in the Handbuch der Physiologie des Menschen für Vorlesungen(1833–1840; manual of physiology), published by German Johannes Müller. Müller’s law of specific nerve energies, which claimed that there was a specific pathway and type of signal for each kind of sensation, was a significant contribution.
German Ernst Weber expanded the study of touch and kinesthesis and created the Weber fraction and the two-point threshold. Gustav Theodor Fechner expanded Weber’s work into Weber’s Law and provided a rationale and methodology for early psychology with his development of psychophysical methods.
Frenchman Paul Broca made use of the clinical method of studying brain lesions. With this methodology, the language area was localized in the third frontal convolution of the cortex.
German Hermann von Helmholtz, a student of Müller who argued against his teacher’s support for vitalism, applied the law of conservation of energy to living creatures, measured rate of nerve conduction, and wrote esteemed handbooks on the physics and physiology of vision and audition. An opposing theorist, German Ewald Hering, a nativist, created the opponent process theory of color vision.
In 1870, Germans Gustav Fritsch and Eduard Hitzig introduced electrical stimulation of the brain, which demonstrated the motor areas of the brain.
From the middle to the latter part of the nineteenth century, Englishman Francis Galton, a cousin of Charles Darwin who was also interested in evolution, promoted mental testing and the study of individual differences. He also stimulated the work of Englishman mathematician Karl Pearson, who invented the statistics to support such studies and much of psychology.
By 1902, an American, Shepard Ivory Franz, combined the ablation technique with training procedures to investigate the function of the frontal lobes in cats. His work led to the work of the great American neuropsychologist Karl Lashley, who led the quest to find the neural basis for memory in his 1950 work In Search of the Engram. Two of Lashley’s students, Canadian Donald O. Hebb, with his work on cell assemblies and phase sequences, and American Roger Sperry, with his work on split-brain preparations in the 1960s, would do much to promote neuropsychology and prepare for cognitive science.
In 1879, Wilhelm Wundt, a student of Helmholtz, brought together his two disciplines of physiology and philosophy by creating a laboratory for experimental psychology at the University of Leipzig in Germany. His laboratory attracted many of the individuals who would become leaders in the new science of psychology. Among these were German Oswald Külpe, Englishman Edward Titchener, and American James McKeen Cattell.
Meanwhile, in the United States, William James, a scientist and philosopher who was familiar with European scholarly trends, published the defining American work on psychology, The Principles of Psychology (1890). This became the dominant text in the English-speaking world and attracted many more Americans to the study of psychology. Both Wundt and James were instrumental in separating psychology from other disciplines both in methodology and in subject matter. Both saw psychology as an introspective science that was to study adult human consciousness. Introspection required that the investigator focus on her or his own experience or awareness, that is, what the individual is thinking and feeling at any one moment.
There were very quickly a number of individuals who either agreed partly or disagreed wholly with Wundt and James. Some of these individuals argued their points persuasively and a number of schools or points of view coalesced around them during the last decade of the nineteenth century and the first several decades of the twentieth century.
Coming from the German rationalist tradition of philosophy, Wundt took as his goal the understanding of consciousness using the method of introspection. Wundt’s point of view has become known as voluntarism. Wundt stressed the role of will, choice, and purpose, all of which he saw present in attention and volition.
Wundt’s student Titchener created a somewhat similar school of thought when, in 1892, he came to Cornell University in Ithaca, New York. Titchener also wanted to study consciousness using the introspective method. He differed from Wundt in that his preferred philosophy was English empiricism, and this led him to a different understanding of consciousness. His approach was to discover the elements of consciousness, and this approach was called structuralism. His successful program led to a strong interest in experimentation, especially on sensation and perception, in American psychology. He trained a large number of Americans in the almost four decades that he taught at Cornell.
American psychologists were not wholly devoted to either Wundt’s or Titchener’s approach to psychology even if they had received their PhDs with them. Instead, they often were motivated by their appreciation for the work of Charles Darwin, who had published his theory of evolution in his famous On the Origin of Species by Means of Natural Selection (1859). Darwin’s writing had been popularized in the English-speaking world by the English writer and speaker Herbert Spencer, who promoted the idea of social Darwinism, that is, that processes of competition among groups of humans would weed out the unfit and thus help to perfect the human race. Following Spencer, many psychologists in the United States saw adaptation as a fundamental concern for their academic field. Among these was philosopher and psychologist John Dewey, whose 1896 article, “The Reflex Arc Concept in Psychology,” was seen as the formal beginning of the school of functionalism.
One student of both Wundt and James who was very influential in early functionalism was American G. Stanley Hall, who founded the American Journal of Psychology in 1887 and who founded Clark University and its psychology department in 1888. He was a leading proponent for developmental psychology, the founder of the American Psychological Association (in 1892), and an untiring organizer.
Very influential in the promotion of applied psychology was a Prussian student of Wundt who had followed James in the laboratories of Harvard University, Hugo Münsterberg, who arrived at Harvard University in 1892.
Two major branches of the school of functionalism were associated with the University of Chicago and Columbia University. There were three leaders at the University of Chicago. Dewey served from 1894 to 1904, when he moved to Teacher’s College at Columbia University. He was succeeded by James Rowland Angell, who served for twenty-five years and who was followed by his student, Harvey Carr, who specialized in the adaptive acts of learning and perception.
At Columbia University, the first significant leader was James McKeen Cattell, who accepted a professorship in 1891 and who stayed for twenty-six years. In addition, very influential was a student of Cattell, Robert S. Woodworth. Woodworth wrote extensively on many topics in psychology, including physiological psychology, the history of psychology, motivation, and experimental psychology. He wrote the significant Experimental Psychology in 1938. The third major influence at Columbia was the very productive Edward L. Thorndike. Thorndike was active at Columbia from 1899 until 1940. He wrote on animal learning, developing a theory called connectionism that accounted for learning in an animal or human on the basis of a strengthening of a connection between a stimulus and a response. Besides learning theory, Thorndike also wrote on verbal behavior, educational practices, intelligence testing, and the measurement of other types of psychological and sociological phenomena. As a school of thought, functionalism came to represent the interests of a great number of American psychologists who were involved in areas that called for practical intervention such as testing, clinical, social, and developmental psychology.
The reaction to Wundtian psychology took a different direction in Europe. Influenced by a group of teachers who adopted a more holistic view of human functioning, a system known as Gestalt psychology started in Germany in 1910. Among the teachers was Franz Clemens Brentano. Brentano, trained in Aristotelian philosophy, promoted an “act psychology,” which stated that the study of the mind had to do with mental acts (such as willing or perceiving), not the study of consciousness divisible into elements. One of Brentano’s students at the University of Vienna was Austrian Christian von Ehrenfels, who was himself licensed to teach at Vienna in 1888. Ehrenfels wrote a paper, “Über Gestaltqualitäten” (1890; on Gestalt qualities), that would be the formative document in the thinking of all future Gestalt psychologists. This paper asserted that the significant aspect in any perception was the pattern created by the individual elements and not the individual elements themselves, as with the melody rather than the individual notes of the melody. Foremost among the Gestalt psychologists was Czech-born Max Wertheimer, who received his PhD in 1904 from the University of Würzbürg. In 1910, Wertheimer involved the two other founders of Gestalt psychology in a study of apparent movement that became known as the phi phenomenon. These two were German Kurt Koffka and Estonian Wolfgang Köhler. Both had just received their PhDs at the University of Berlin under the direction of German Carl Stumpf, who was himself a student of Brentano and whose lifework was devoted to the study of music, space perception, and audition. His work would lead to the phenomenological approach that was common to Gestalt psychology. In the 1930s, with the coming to power of National Socialism in Germany, the three main Gestalt psychologists—Wertheimer, Koffka, and Köhler—emigrated to the United States, where they found behaviorism’s associationism and elementism as unacceptable as it was in both Wundtian psychology and psychoanalysis.
William McDougall was born in England, educated in England and at the University of Göttingen in Germany, and began his teaching at Oxford University in England. In 1920, he came to the United States, where he developed his brand of psychology called hormic psychology, from the Greek word horme, which means “urge.” He called himself a behaviorist, but one who viewed behavior as instinctually directed and at the same time as purposeful. McDougall was widely admired but seemed out of step with the dominant behaviorism of his time. His views are much more congenial with the cognitive psychology of the late twentieth century.
Basing part of his rationale on the work of Russian reflexologist Ivan Petrovich Pavlov, who discovered the principles of conditioning while doing work on the digestive system of dogs, American John Broadus Watson promoted a radical behaviorism that rejected introspection as a method and suggested that the study of animal behavior was the equivalent of the study of human behavior. His lectures at Columbia University, which were published in the Psychological Review in 1913 under the title “Psychology as the Behaviorist Views It,” are seen as the beginning of behaviorism. They certainly separated behaviorism from both structuralism and functionalism.
In 1900, Mary W. Calkins, an American student of James, began her defense of a self psychology. Despite the functionalist interest in adaptation and the behaviorist rejection of introspection, Calkins would continue to assert that the self was an existential reality; that is, it was knowable in one’s own awareness. After her death in 1930, the self came to be considered a conceptualization. Gordon Allport, an American who studied extensively in Europe, became the leading self psychologist for another thirty years. In Allport’s later years, clinicians such as Carl R. Rogers, who developed client-centered therapy (later known as person-centered therapy), would keep the idea of self and its centrality alive in psychology until the cognitive revolution of the 1960s and 1970s allowed the self to become a popular integrating construct again.
Austrian physician Sigmund Freud published Studien über Hysterie (1895; Studies in Hysteria, 1950) and began the school of therapy known as psychoanalysis. Psychoanalysis soon became a general theory of personality. Freud’s possessiveness about the theory led to the ouster from his inner circle of two theorists who would go on to create their own approaches to psychoanalysis. The first was Austrian Alfred Adler in 1911. Adler’s point of view would become known as individual psychology. The second, in 1913, was Swiss Carl Jung, who questioned the sexual basis of the motivating energy proposed by Freud. Jung’s point of view has become known as analytical psychology. By the 1930s, Freud’s classic psychology of the unconscious had shifted to a greater appreciation of the conscious. Thus, Freud’s daughter, Anna Freud, following the interests of her father, published Das Ich und die Abwehrmechanismen (1936; The Ego and the Mechanisms of Defense, 1937). Classic psychoanalysis had changed into ego psychology. The best-known representative of the new ego psychology was the child analyst and writer Erik H. Erikson . Erikson, who was born in Germany and who had been analyzed by Anna, came to the United States in 1933. His Childhood and Society (1950) made connections to and enriched developmental psychology, especially in terms of his reworking of Freud’s five developmental stages into the “eight ages of man.”
Frenchman Alfred Binet published the first individual test of intelligence in 1905. Lewis Madison Terman, an American student of G. Stanley Hall, published his revision of Binet’s test, called the Stanford Binet, in the United States in 1912. An industry was born. The test was reissued in 1916, 1937, 1960, 1986, and 2003. Group tests of intelligence were developed for the military during both World War I and World War II. The needs of the military also promoted another applied psychology: clinical psychology. In World War II, short-term psychotherapy was found to be useful in returning combatants to active service. Many academic psychologists were pressed into training programs to become psychotherapists. By the time the war ended, a number of psychologists viewed themselves as clinicians and returned to redirect graduate programs in psychology toward clinical psychology. By the late 1940s testing, diagnosis, and clinical practice were well established.
In 1924, a group of philosophers in Vienna, Austria, known as the Vienna Circle, revised and refined positivism into logical positivism, and in 1927, Percy Williams Bridgman, an American physicist, proposed operationism, in which every theoretical construct would be defined by the operations that were used to measure it. These developments allowed experimenters to deal positivistically with abstract variables and led to a more sophisticated behaviorism labeled neobehaviorism. Americans Edward C. Tolman, Clark L. Hull, and B. F. Skinner were notable representatives of neobehaviorism, which specialized in the study of learning and motivation, mostly with nonhuman species. Skinner differed from the others in that he favored induction and description as the basis for his studies. Neobehaviorism was superseded by changes that brought about the cognitive revolution in the 1960s and 1970s. Its heritage remains in psychology in the area of methodology.
In addition, by the 1950s, a rift that had begun in the days of Titchener between those who saw themselves as pure scientific psychologists as opposed to those who practiced an applied psychology was reconceptualized as a conflict between the academic psychologists who maintained a behavioristic approach and the clinicians who were heavily influenced by psychoanalysis and were beginning to appreciate Rogers’s person-centered approach. This struggle was exacerbated by the growing number of practitioners, who began to outnumber the academic psychologists. One result of this disciplinary conflict was the foundation of a separate organization for the academics, the American Psychological Society, formed in 1988.
The emergence of the computer both as a tool and as a model of the human mind had a major effect on psychology. Neuroscience, philosophy, anthropology, linguistics, artificial intelligence, and psychology came together in the 1960s to form the basis for a new discipline: cognitive science. The new technology and the opportunity to work with people and ideas from other disciplines freed psychology to reinvestigate questions of mental functioning and consciousness.
In 1954, American Abraham Maslow published the influential Motivation and Personality, which began humanistic psychology, a movement seen by Maslow as an antidote to the dehumanizing assumptions of both behaviorism and psychoanalysis. By 1961, there was the Journal of Humanistic Psychology and, by 1962, the American Association of Humanistic Psychologists. Rogers, with his person-centered therapy, added to the attractiveness of the movement for American psychologists. Its emphasis on admitting the whole person to psychology gained more general acceptance and, together with the cognitive revolution, promoted a more humanistic and cognitively oriented general psychology.
Developmental psychology, building on the work of Swiss Jean Piaget from the 1920s through the 1960s, and cognitive psychology, stimulated by the early 1960s work of Americans George A. Miller and Jerome Bruner, began once again to study consciousness and its development, but this time from infancy through adulthood. A student of Miller, German-born Ulric Neisser built on this and his earlier work, Cognitive Psychology (1967), to bring to the 1980s and 1990s an integrative approach to consciousness, concept formation, perception, and selfhood. In general, the period was one of eclecticism and was labeled neofunctionalism by one historian.
Another trend that impacted psychology was postmodern thought. Although present in philosophy and anthropology through the twentieth century, it became obvious in psychology only in the 1970s, where it was known as social constructionism. Since the 1970s, it has made its presence obvious in the subfield called cultural psychology and in social psychology. When applied to personality development, the concept of narrative as an inborn mechanism has become a focus for those who wish to describe the process of self-development.
Notable milestones in genetics and neuroscience during the 2000s and 2010s provided the basis for ongoing research into human development and pathology. In April 2003, the Human Genome Project reported that it had produced a finished version of the human genome sequence, with 99 percent of genome sequenced, an accuracy rate of less than one error per ten thousand nucleotide base pairs, and less than four hundred sequence gaps. In 2013, the Obama administration announced the formation of Brain Research through Advancing Innovative Neurotechnologies, also called the BRAIN Initiative or Brain Activity Map Project. The initiative's goal is to map every neuron in the human brain over a ten-year period. In April 2014, the first installment of the National Institute of Mental Health–funded BrainSpan Atlas of the Developing Human Brain project, produced by Seattle's Allen Institute for Brain Science, was reported online by Nature. The project intends to profile gene activity over the course of the brain's development and thereby help researchers understand the genesis of brain-based disorders such as schizophrenia and autism.Bibliography
Allen Institute for Brain Science. BrainSpan Atlas of the Developing Human Brain. Allen Inst. for Brain Science, 2004–2014. Web. 27 June 2014.
Brett, George Sidney. A History of Psychology. London: Routledge, 2014. Digital file.
Gardner, Howard. The Mind’s New Science: A History of the Cognitive Revolution. New York: Basic, 1998. Print.
Hergenhahn, B. R. An Introduction to the History of Psychology. 6th ed. Belmont: Wadsworth, 2009. Print.
Hilgard, Ernest Ropiequet. Psychology in America: A Historical Survey. New York: Harcourt, 1987. Print.
Hunt, Morton. The Story of Psychology. 2d ed. New York: Doubleday, 2007. Print.
Koch, Sigmund, and David Leary, eds. A Century of Psychology as Science. Washington, DC: American Psychological Association, 1992. Print.
Russell, Bertrand. A History of Western Philosophy. New York: Simon, 1945. Print.
Stevenson, Leslie, and David L. Haberman. Ten Theories of Human Nature. 5th ed. New York: Oxford UP, 2009. Print.
Stroebe, Wolfgang, and Arie W. Kruglanski. Handbook of the History of Social Psychology. New York: Psychology, 2012. Digital file.