The founding of the first laboratory in experimental psychology has generally been credited (but not without some debate; see Green, 2000) to German physician and physiologist Wilhelm Wundt (1832–1920). Wundt received his MD degree from the University of Heidelberg in 1855. The natural sciences had become legitimized as a proper field of study and were allied with medical training in the universities.
Research laboratories for scientific investigations were an accepted part of the university structure, and careers in scientific research were made possible Ben-David, 1971). Wundt, trained in physiology as part of his medical education, pursued independent research as a student and chose physiology, not medicine, for his career (Bringmann, Balance, & Evans, 1975). As a lecturer at the University of Heidelberg, Wundt offered courses privately for a fee, conducted research, and became an assistant to Helmholtz. In 1862, he offered his first course in “psychology as a natural science” (Bringmann et al., 1975) at Heidelberg, and in 1873–1874, the first edition of his book, Grundzüge der physiologischen Psychologie (Principles of Physiological Psychology) called for the recognition of psychology as a discipline independent of philosophy and physiology (Blumenthal, 1985a; Fancher, 1996; but see Danziger, 1990).In 1875, at the age of 42, Wundt accepted a position as professor of philosophy at the University of Leipzig, where he established the first experimental research program in psychology. Chairs in science carried more prestige than those in
philosophy, but the limited number of chairs available in science at the time made one in philosophy attractive to Wundt (Ben-David & Collins, 1966). Thus, psychology, like other sciences before it, began as part of the curriculum in philosophy; the acceptance of research laboratories as part of the university establishment permitted the founding of a laboratory in conjunction with Wundt’s research. Wundt had been engaged in psychological research for some time. As early as 1857, he constructed an apparatus in his home to measure reaction time and began accumulating a collection of instruments (kymographs, chronoscopes, tachistoscopes, and devices to measure responses) that were eventually employed in his laboratory (Blumenthal, 1985a). Upon his arrival at Leipzig, a space in a former university refectory building was assigned to Wundt to permit him to store his apparatus and to conduct demonstrations
associated with his lectures. In 1879, Wundt and students Max Friedrich and American G. Stanley Hall began a program of independent research (Boring, 1965; Bringmann,
Bringmann, & Ungerer, 1980) that initiated psychology as “the organized and self-conscious activity of a community of investigators” (Danziger, 1990). In 1881, the first issue of Wundt’s journal, Philosophische Studien, appeared featuring
Friedrich’s dissertation research, and by 1883, the laboratory had acquired the status and budget of a research institute within the university (Boring, 1965; Bringmann et al., 1980;Danziger, 1990). Experimental psychology as practiced by Wundt and his students at Leipzig employed the methods of physiology to study the contents and processes of individual human consciousness. Among the studies pursued in Wundt’s laboratory were psychophysical experiments to analyze and measure sensations, reaction-time experiments to measure the duration of mental processes, and experiments on attention, memory, and the association of ideas (Cattell, 1888). Wundt
extended Donders’s subtractive procedure to the measurement of other mental processes, including association and judgment. His American student, James McKeen Cattell (1860–1944), elaborated on Donders’ method in his research investigations at Leipzig between 1883 and 1886 and measured the speed of verbal associations. In a particularly innovative set of experiments, he varied the number of letters, numbers, words, or sentences a stimulus card contained and exposed the card to observers very briefly (.01 sec) to measure the number of items that could be contained in consciousness at one time; the result was an estimate of the span of attention, or span of apprehension (Ladd, 1888). Early reports of experiments were enthusiastic in detailing the empirical results that the laboratory could provide but that were
beyond the reach of the older philosophical psychology. Reports that the time taken to name a short word was .05 seconds less than the time taken to name a letter of the alphabet (Jastrow, 1886), or that the time taken to name colors or pictures was “about twice as long as the corresponding times for recognizing and naming letters or words” (Cattell, 1947b), exemplify this fascination with quantifying dimensions of mental processes. Intrigued by the individual differences in performance that he observed, Cattell would later explore the range of individual differences in a program of mental testing at Columbia University (Cattell, 1947c;Wundt, 1974; Fancher, 1996; Sokal, 1987). In addition to the psychophysical and reaction time measures that he employed, Wundt’s physiological psychology made use of reports of conscious experience. He distinguished between Selbstbeobachtung (self-observation), the introspection of the philosophers, and innere Wahrnehmung (internal perception); the basis of conscious experience. Selfobservation, as traditionally employed, could not meet the standard of scientific observation. To make a scientific introspection
possible required careful control over the stimulus that was to produce the mental event to be observed and as short an interval as possible between the observation of the event and its recall and report. This was to be achieved by the experiment conducted in the laboratory under carefully controlled conditions; experimentelle. Selbstbeobachtung was the form of introspection raised to scientific status by experimental procedures (although terminology when translated from the German can be problematic; compare Blumenthal, 1985a, p. 28 and Danziger, 1980, p. 244). In any case, to ensure that this observational procedure could be a rigorous scientific
method to assess mental events and did not lapse into the older philosophical reflection,Wundt established rules or guidelines by which introspection might achieve scientific validity:
(1) The observer, if at all possible, must be in a position to determine when the process is to be introduced.
(2) He must be in a state of ‘strained attention’.
(3) The observation must be capable of being repeated several times;
(4) The conditions of the experiment must be such as to be capable
of variation of the strength and quality of the stimuli (R. I. Watson & Evans, 1991).
By knowing when a process is to be introduced (a stimulus presented), an observer may concentrate (strainedattention) on the observation to be made and, to ensure reliability, be able to repeat the process. Varying conditions allowed the observer to identify changes in consciousness as a function of changes in the conditions of the experiment. Replicating conditions enhanced the reliability of the observations
to approach those of the observation of external events. These tight restrictions meant, with minor exceptions, that “the introspective reports from his laboratory are
very largely limited to judgments of size, intensity, and duration of physical stimuli, supplemented at times by judgments of their simultaneity and succession” (Danziger, 1980). Confidence in the results of introspection depended upon confidence in the skill and experience of the observer who, as the source of the data, was the critical component in psychological experiments. In Wundt’s laboratories, the observer possessed psychological authority and expertise. Experimental control over the introspective process was obtained not only by the rules for the conduct of an experiment but also by the use of observers whose habits of attentiveness and
quickness of observation and reporting provided reliable data (Danziger, 1980). Published reports of experiments conducted in German and American laboratories identified each of the observers and their level of experience in introspection
(e.g., Geissler, 1909; cf. Bazerman, 1987). The experimenter played a secondary role in manipulating the apparatus, presenting stimuli, and recording responses. The division of labor between experimenters and observers, who were colleagues and collaborators, was primarily one of convenience; roles were routinely exchanged, with few exceptions: Wundt, for example, served as an observer in some of the Leipzig
experiments but never as experimenter. However, the published reports of experiments by Oswald Külpe (1862–1915), a former student of Wundt, failed to identify the observers in experiments that used introspection in his laboratory at the University of Würzburg. Külpe’s experiments were designed to explore the thought processes
involved in making inferences and judgments. The Würzburg method of introspection, “systematic introspection” (Danziger, 1980; 1990) or “systematic introspectionism”
(Blumenthal, 1985b, p. 64), was a form of self-reflection that required thinking about a problem to solve and then retrospectively recounting the thought processes that led to its solution. In these experiments, the experimenter would interrupt
the observer’s introspective report with questions designed to probe the content of consciousness. This procedure,which shifted the power and authority in the experimental situation from the observer to the experimenter, represented a departure from the careful experimental control over introspection exercised in Wundt’s laboratory. Wundt vigorously opposed the Würzburg method as unreliable(Blumenthal, 1985a; Leahey, 1981), particularly as it was applied to those higher mental processes that Wundt believed to be beyond the reach of introspection and, indeed, of any laboratory method. Others pointed out that the “demand characteristics” inherent in this interrogation procedure(Müller, 1911; cited in Kusch, 1995) were likely to bias an observer’s responses. The status of introspection as a laboratory method would concern psychology well into the twentieth century.
Wundt argued that experimental self-observation could reveal the existence of mental processes such as apperception (an active attentional process that organized perceptions), volition (will or effort), and emotion, but he strongly believed that these higher mental processes could not be studied using the experimental method. The only methods appropriate for the study of these hidden, higher cognitive processes
were naturalistic observation and history. Wundt’s physiological psychology was one of “outer phenomena,” sensation,perceptions, and movement, his Völkerpsychologie,”
the study of language, religion, myth, and culture, was one of “inner phenomena” (Leahey, 1981). Wundt’s Völkerpsychologie encompasses 10 volumes. Because so many American students studied at Leipzig (Benjamin, Durkin, Link, Vesta, & Acord, 1992), Wundt assumed a position of particular significance in the accounts of the origins of the new psychology. Nevertheless, pioneers in the new discipline at other German universities attracted their share of students from the United States and from other
countries. The development of psychology, even in its early stages, was not the work of a single individual. Much of the development of psychology consisted of attempting to study in the laboratory those psychological processes that Wundt had declared beyond the reach of experiment.
Friday, July 25, 2008
BEYOND THE FIRST LABORATORY: EVOLUTION
Psychology in Germany One of Wundt’s contemporaries who believed that higher mental processes could be the object of experimental investigation was Hermann Ebbinghaus (1850–1909). Inspired by the psychophysics of G. T. Fechner and philosopher J. F.
Herbart’s attempt to apply mathematics to mental representations, Ebbinghaus used precise quantitative methods to investigate memory (Murray, 1976). He served as both the experimenter and the subject of his investigations. In order to have relatively homogeneous material to learn and to reduce the impact of any previous semantic associations, such as occurred in his early experiments in learning and remembering
poetry, Ebbinghaus developed the “nonsense syllable,” largely pronounceable consonant-vowel-consonant combinations. He created syllable lists of various lengths that he learned and then later relearned after different lengths of time. The percentage of time saved in relearning the lists became known as the “savings method” of memory (Murray, 1976; Hoffman, Bringmann, Bamberg, & Klein, 1987). Ebbinghaus found that the amount of time spent in relearning lists was greater for longer lists and for longer retention intervals. The graph of his results became the standard curve of forgetting, still reproduced in textbooks as a classic result. The curve showed that recall of learned lists was perhaps 85% after one hour, approximately 50% after one day, and as little as 15% after about six days. These findings stimulated a long tradition of memory research (e.g., Postman, 1968). After publication of his monograph Über das Gedächtnis (On Memory), Ebbinghaus established laboratories at several universities and attracted some American students, but his time was increasingly devoted to a editing a journal and writing (Fuchs, 1997). Leadership of memory research fell to Georg Elias Müller (1850–1931) at Göttingen University. Müller, a dedicated experimentalist, invented the memory drum, a mechanical device for presenting one verbal stimulus at a time, used in conjunction with experiments on serial list learning and list retention. The memory drum, modified subsequently by Müller for research in paired associate learning (Haupt, 1998), became a standard piece of laboratory equipment for studies of verbal learning and memory until replaced by the computer. Müller’s research reports on his studies of memory extended from 1893 to 1917 and included “the theoretical contributions of retroactive inhibition, perseveration, and consolidation” (Murray & Bandomir, 2000). Müller initiated what later was termed the interference theory of forgetting, a position that argues that forgetting is a function of the interference among competing memories at the time that a particular memory is being retrieved and not a function of a decay or loss of memory traces (Murray, 1988). The topic was not addressed directly by Ebbinghaus, but the rapid forgetting that his retention curve recorded has been interpreted as offering evidence of the role of interference in memory (Murray, 1988; Underwood, 1957). Müller’s experimental interests were not limited to memory research. He built on the contributions of Fechner, Ewald Hering, and Mary Whiton Calkins in becoming a leader in the development of the methodology of psychophysics, conducting studies on color vision and investigating paired-associate
verbal learning (Blumenthal, 1985b; Murray, 1976). His laboratory was well supplied with experimental apparatus (Haupt, 1998) and attracted a number of psychologists to
pursue research with him. Müller’s laboratory seems to have been especially hospitable to women interested in psychology; among those studying at Göttingen were, for example, Americans Mary Whiton Calkins, Eleanor Gamble, and Lillien Jane Martin. Other laboratories and universities were less open in this regard (Furumoto, 1987; Scarborough & Furumoto, 1987).
Herbart’s attempt to apply mathematics to mental representations, Ebbinghaus used precise quantitative methods to investigate memory (Murray, 1976). He served as both the experimenter and the subject of his investigations. In order to have relatively homogeneous material to learn and to reduce the impact of any previous semantic associations, such as occurred in his early experiments in learning and remembering
poetry, Ebbinghaus developed the “nonsense syllable,” largely pronounceable consonant-vowel-consonant combinations. He created syllable lists of various lengths that he learned and then later relearned after different lengths of time. The percentage of time saved in relearning the lists became known as the “savings method” of memory (Murray, 1976; Hoffman, Bringmann, Bamberg, & Klein, 1987). Ebbinghaus found that the amount of time spent in relearning lists was greater for longer lists and for longer retention intervals. The graph of his results became the standard curve of forgetting, still reproduced in textbooks as a classic result. The curve showed that recall of learned lists was perhaps 85% after one hour, approximately 50% after one day, and as little as 15% after about six days. These findings stimulated a long tradition of memory research (e.g., Postman, 1968). After publication of his monograph Über das Gedächtnis (On Memory), Ebbinghaus established laboratories at several universities and attracted some American students, but his time was increasingly devoted to a editing a journal and writing (Fuchs, 1997). Leadership of memory research fell to Georg Elias Müller (1850–1931) at Göttingen University. Müller, a dedicated experimentalist, invented the memory drum, a mechanical device for presenting one verbal stimulus at a time, used in conjunction with experiments on serial list learning and list retention. The memory drum, modified subsequently by Müller for research in paired associate learning (Haupt, 1998), became a standard piece of laboratory equipment for studies of verbal learning and memory until replaced by the computer. Müller’s research reports on his studies of memory extended from 1893 to 1917 and included “the theoretical contributions of retroactive inhibition, perseveration, and consolidation” (Murray & Bandomir, 2000). Müller initiated what later was termed the interference theory of forgetting, a position that argues that forgetting is a function of the interference among competing memories at the time that a particular memory is being retrieved and not a function of a decay or loss of memory traces (Murray, 1988). The topic was not addressed directly by Ebbinghaus, but the rapid forgetting that his retention curve recorded has been interpreted as offering evidence of the role of interference in memory (Murray, 1988; Underwood, 1957). Müller’s experimental interests were not limited to memory research. He built on the contributions of Fechner, Ewald Hering, and Mary Whiton Calkins in becoming a leader in the development of the methodology of psychophysics, conducting studies on color vision and investigating paired-associate
verbal learning (Blumenthal, 1985b; Murray, 1976). His laboratory was well supplied with experimental apparatus (Haupt, 1998) and attracted a number of psychologists to
pursue research with him. Müller’s laboratory seems to have been especially hospitable to women interested in psychology; among those studying at Göttingen were, for example, Americans Mary Whiton Calkins, Eleanor Gamble, and Lillien Jane Martin. Other laboratories and universities were less open in this regard (Furumoto, 1987; Scarborough & Furumoto, 1987).
Psychology in America
The results of German investigations in sensory physiology and their significance for the philosophy of mind did not go unnoticed by Americans in the period after the Civil War. William James, abroad for his health and to further his medical studies, wrote to a friend: “It seems to me that perhaps the time has come for psychology to begin to be a science—some measurements have already been made in the region lying between the physical changes in the nerves and the appearance of consciousness at (in the shape of sense perceptions) and more may come of it. Helmholtz and a man named
Wundt at Heidelberg are working at it” (James, 1920). In antebellum America, the dominant philosophical tradition was derived from England and Scotland, as exemplified in John Locke’s Essay on Human Understanding and the texts of the scottish commonsense realists, Thomas Reid, Dugald Stewart, and Thomas Brown (Evans, 1984, Fay, 1939; Fuchs, 2000a, Roback, 1952) with only modest representation of German (Hickok, 1854; Rauch, 1840) and French (Cousine, 1864) philosophy. British philosophy was empirical, gathering information about mind and mental processes from introspective observation, observation of the behavior of others, and observations of individuals recorded in medical treatises, court proceedings, literature, and poetry. The data were classified under general faculties or categories of mind, such as the intellect and the sensibilities (cognitive and conative, emotional, or motivational states) and the many possible subdivisions, such as memory and reasoning, instincts, and desires (Fuchs, 2000a, 2000b). Results from the investigations in psychophysics, sensory physiology, and the early experiments in psychology were incorporated into later textbooks of intellectual and mental philosophy (e.g., Porter, 1868; McCosh, 1886, 1887). Adding the empirical data to the theological concerns for “soul” did not change the traditional philosophical position of these texts. Even a textbook by G. T. Ladd (1842–1921) that represented the new psychology did not escape fully the theological concerns of the “old psychology” (Ladd, 1888; Evans, 1984; E. Mills, 1969). Americans traveled abroad for advanced education at British and continental universities after the Civil War; painters, writers, and scientists went in large numbers. With the postwar establishment of the new land-grant universities,
professional opportunities arose for faculty members, especially in the sciences, for education not yet available in the United States. With the zeal of converts and crusaders, the first generation of North American psychologists returned from their study abroad to stimulate the development of graduate education within established American colleges and universities and the newer land-grant universities (Kohler,
1990). They wrote textbooks to incorporate the results of the continental laboratories, developed courses for undergraduate and graduate students, created laboratories for teaching and research, and founded journals for the publication of
research from the newly established laboratories. The laboratories came to be the locus of education in psychology in universities and colleges (Calkins, 1910; Sanford, 1910) and came to symbolize psychology as science, while psychology,lodged within departments of philosophy, became the introductory course required for further study in philosophy (Fuchs, 2000b).
Wundt at Heidelberg are working at it” (James, 1920). In antebellum America, the dominant philosophical tradition was derived from England and Scotland, as exemplified in John Locke’s Essay on Human Understanding and the texts of the scottish commonsense realists, Thomas Reid, Dugald Stewart, and Thomas Brown (Evans, 1984, Fay, 1939; Fuchs, 2000a, Roback, 1952) with only modest representation of German (Hickok, 1854; Rauch, 1840) and French (Cousine, 1864) philosophy. British philosophy was empirical, gathering information about mind and mental processes from introspective observation, observation of the behavior of others, and observations of individuals recorded in medical treatises, court proceedings, literature, and poetry. The data were classified under general faculties or categories of mind, such as the intellect and the sensibilities (cognitive and conative, emotional, or motivational states) and the many possible subdivisions, such as memory and reasoning, instincts, and desires (Fuchs, 2000a, 2000b). Results from the investigations in psychophysics, sensory physiology, and the early experiments in psychology were incorporated into later textbooks of intellectual and mental philosophy (e.g., Porter, 1868; McCosh, 1886, 1887). Adding the empirical data to the theological concerns for “soul” did not change the traditional philosophical position of these texts. Even a textbook by G. T. Ladd (1842–1921) that represented the new psychology did not escape fully the theological concerns of the “old psychology” (Ladd, 1888; Evans, 1984; E. Mills, 1969). Americans traveled abroad for advanced education at British and continental universities after the Civil War; painters, writers, and scientists went in large numbers. With the postwar establishment of the new land-grant universities,
professional opportunities arose for faculty members, especially in the sciences, for education not yet available in the United States. With the zeal of converts and crusaders, the first generation of North American psychologists returned from their study abroad to stimulate the development of graduate education within established American colleges and universities and the newer land-grant universities (Kohler,
1990). They wrote textbooks to incorporate the results of the continental laboratories, developed courses for undergraduate and graduate students, created laboratories for teaching and research, and founded journals for the publication of
research from the newly established laboratories. The laboratories came to be the locus of education in psychology in universities and colleges (Calkins, 1910; Sanford, 1910) and came to symbolize psychology as science, while psychology,lodged within departments of philosophy, became the introductory course required for further study in philosophy (Fuchs, 2000b).
William James and Evolutionary Theory
The essential break with the mental philosophical past was achieved by William James, whose Principles of Psychology (James, 1890) represented the first of the modern textbooks (Evans, 1981). James was a transitional figure, with one foot in philosophy and the other in the empiricism of the new science. His text, while still too philosophical for some of his more empirical colleagues (see, e.g., Evans, 1981; Ross,1972), nevertheless effectively cut the discipline’s past ties to theology. James was attracted to the new psychology by the possibility of using science to pursue philosophical issues more deeply (Croce, 1999) and called for psychology to be a natural science (James, 1892a). He recognized that while psychology was not yet an established science, it constituted the hope of a science (James,1892b). His textbooks (James,1890, 1892b) attracted recruits to psychology’s banner to attempt to realize that hope. William James had been appointed an instructor at Harvard in physiology in 1872; like Wundt, James had earned an MD degree and, again like Wundt, had no real interest in practicing medicine. In 1875, he offered a graduate course at Harvard on the Relations between Psychology and Physiology” and, again like Wundt, had rooms assigned to him to use for experimental demonstrations to augment his teaching. James, however, was never very enthusiastic about laboratory work; he once declared the psychophysics could never have arisen in a country in which the natives could be bored (Boring, 1950). As a text for his course in psychology, James adopted Principles of Psychology (1855) by Herbert Spencer (1820–1903). A course featuring discussion of evolutionary theory was a novelty, since the older, pre–Civil War
mental philosophy texts ignored evolutionary theory, while textbooks written after the war wrestled uncomfortably and unsuccessfully with integrating evolutionary theory with theological concerns. The theory of evolution by natural selection proposed by Charles Darwin (1809–1882) had an enormous influence on American psychology. In his book On the Origin of Species (1859), Darwin presented evidence to support his theory of evolution and proposed natural selection as the mechanism
responsible. To account for the evolution of intelligent behaviors, Darwin appealed to two mechanisms, sexual selection (the evolution of traits that facilitate mating
success) and, more tentatively, as a second mechanism, the inheritance of acquired characteristics (Darwin, 1871). Jean-Baptiste de Lamarck (1744–1829) had proposed that learned changes in behavior that occur during an animal’s lifetime can be passed down to that individual’s offspring through biological inheritance. This view was shared by Herbert Spencer, who, unlike Darwin, viewed the evolutionary process as a linear progression from “lower” to “higher” forms (Spencer, 1855). Spencer coined the phrase “survival of the fittest” to suggest that those individuals who were best
adjusted to their environments would survive. Learned behaviors that facilitated this adjustment to the environment would then be passed to subsequent generations. Adjustment was to the individual’s survival what adaptation was to the survival of the species (Boakes, 1984; Buxton, 1985a;1985b). The absence of evidence for Lamarck’s theory led to its abandonment, and evolutionary theory was left with natural selection as the only mechanism of evolutionary change. Nevertheless, Spencer’s focus on adaptability during an individual’s lifetime (learning) and Darwin’s emphasis on individual development during childhood, differences among
individuals, the relation between structure and function, and the continuity between animals and humans contributed substantially to the expansion of the topics that psychologists pursued in the name of psychological science.
mental philosophy texts ignored evolutionary theory, while textbooks written after the war wrestled uncomfortably and unsuccessfully with integrating evolutionary theory with theological concerns. The theory of evolution by natural selection proposed by Charles Darwin (1809–1882) had an enormous influence on American psychology. In his book On the Origin of Species (1859), Darwin presented evidence to support his theory of evolution and proposed natural selection as the mechanism
responsible. To account for the evolution of intelligent behaviors, Darwin appealed to two mechanisms, sexual selection (the evolution of traits that facilitate mating
success) and, more tentatively, as a second mechanism, the inheritance of acquired characteristics (Darwin, 1871). Jean-Baptiste de Lamarck (1744–1829) had proposed that learned changes in behavior that occur during an animal’s lifetime can be passed down to that individual’s offspring through biological inheritance. This view was shared by Herbert Spencer, who, unlike Darwin, viewed the evolutionary process as a linear progression from “lower” to “higher” forms (Spencer, 1855). Spencer coined the phrase “survival of the fittest” to suggest that those individuals who were best
adjusted to their environments would survive. Learned behaviors that facilitated this adjustment to the environment would then be passed to subsequent generations. Adjustment was to the individual’s survival what adaptation was to the survival of the species (Boakes, 1984; Buxton, 1985a;1985b). The absence of evidence for Lamarck’s theory led to its abandonment, and evolutionary theory was left with natural selection as the only mechanism of evolutionary change. Nevertheless, Spencer’s focus on adaptability during an individual’s lifetime (learning) and Darwin’s emphasis on individual development during childhood, differences among
individuals, the relation between structure and function, and the continuity between animals and humans contributed substantially to the expansion of the topics that psychologists pursued in the name of psychological science.
Friday, July 18, 2008
Origin Of Scientific Psychology
Historical accounts of the development of scientific psychology place the origins of the discipline in Germany at about the middle of the nineteenth century. The ferment produced by British and continental philosophies of mind and the advances of research in sensory physiology provided the immediate context for the beginning of the new psychology. The pursuit of knowledge about mind and its processes has a history that is embedded in the history of philosophy. The late-eighteenth-century declaration that a true scientific study of the mind was not possible posed a challenge that was answered in the nineteenth century when the possibility of a scientific study of mind emerged within philosophy by the adoption of the experimental methods employed to study the physiology of the senses. The synergy of these nineteenthcentury developments gave impetus to the “new psychology” whose history embodies continued efforts to develop and maintain psychology as a scientific discipline and to extend the methods of science to an ever-widening field of inquiry within the discipline.
The Philosophical Context
Christian Wolff (1679–1754) first popularized the term psychology to designate the study of mind. Wolff divided the discipline between empirical and rational psychology. The data of mind that resulted from observing ourselves and others constituted empirical psychology; rational psychology referred to the interpretation of the data of empirical psychology through the use of reason and logic. These psychologies were characterized as using knowledge acquired through experience (empirical psychology) or using knowledge that the mind possesses independent of experience (rational psychology) (Murray, 1988). Immanuel Kant (1724–1804) denied the validity of any rational psychology because, he argued, rational mental processes must be activated by mental content derived from experience; therefore, the study of mind must be confined to questions appropriate to an empirical psychology (Leary, 1978). An empirical psychology of mental content could not, Kant contended, become a proper natural science because mental events cannot be quantified (i.e., measured or weighed), and thus its data are neither capable of being described mathematically nor subject to experimental manipulation. Finally, Kant asserted, the method of observing the mind—introspection—distorts the events observed by observing them. However, Kant suggested, psychology might improve its status as an empirical science by adopting the methods of anthropology to observe the activities of human beings in realistic settings. This study (Leary, 1978), supplemented by drawing upon literature, history, and biography as sources of information about the manifestation of mind in human activity, would base psychology upon objective observations of public events and avoid the limitations of an empirical psychology based solely on internal observation of private events. Responses to Kant were not long in coming. Jakob Friederich Fries (1773–1843) raised the status of introspection by arguing that it was not inherently more problematic than observing external phenomena; if introspection was unreliable, at least it was not any more so than any other kind of observation. At the same time, Johann Friederich Herbart (1776–1841) offered a system of psychology that was both empirical and mathematical. If psychology needed to be mathematical to be a true science, Herbart proposed that numbers could be assigned to mental events of different intensities and a mathematical description of the relationship among them could be formulated. Herbart could assign numbers to describe experiences of different intensities, but he could not actually measure the subjective intensities in accord with an objective standard. Eduard Friederich Beneke (1798–1854) argued that it was premature to apply mathematics to relationships among mental events absent more accurate empirical observations and reliable means of measurement; psychology could hope to become an experimental discipline by testing “empirical results and theoretical hypotheses under controlled conditions and with the systematic variation of variables”. Kant’s suggestion that psychology should utilize observations of human beings in their social environment, the rescue by Fries of introspection as a method for observing internal events, Herbart’s suggestion that psychological phenomena could, in principle, be described mathematically, and Beneke’s suggestion that psychological experiments were possible contributed to the inception of scientific psychology. By suggesting that a science of psychology was not possible, Kant stimulated both counterarguments and the search for the means to make psychology a scientific discipline of equal rank with the natural sciences. It remained for others to attempt to establish introspection as a scientific method, to devise the conditions and methods of an experiment in psychology, and to quantify psychological phenomena and formulate theoretical and mathematical descriptions of the relationships among them.
The Scientific Context
The emerging natural sciences of the eighteenth and nineteenth centuries became increasingly specialized as knowledge increased and as opportunities for specialized teaching and research came into being in the German universities (Ben-David, 1971). The study of physiology emerged as a discipline separate from anatomy as the nineteenth century began. Studying intact physiological systems, in vivo or in vitro, accelerated the understanding of the functional characteristics of those systems and built on the knowledge gained from the study of anatomy via dissection. The methods and subject matter of physiology, especially sensory physiology, helped to provide the scientific basis for psychology.
Sensory Physiology
Johannes Müller (1801–1858), the “Father of Physiology,” produced the classic systematic handbook (Handbuch der Physiologie des Menschen, 1833–1840) that set forth what was then known about human physiology and offered observations and hypotheses for further research. Among the formulations that Müller provided in the Handbuch was the law of specific nerve energies, which stated that the mind is not directly aware of objects as such but can only be aware of the stimulation in the brain conveyed by sensory nerves. The perceived qualities of stimulation depend upon the sense organ stimulated, the nerve that carries the excitation from the sense organ, and the part of the brain that receives the stimulation. Müller’s pupil, Hermann von Helmholtz (1821–1894), extended the law of specific nerve energies by theorizing that qualities of stimuli within a sensory modality are encoded in the same way that they are encoded among modalities. That is, distinguishing red from green, or a low pitch from a high one, depended upon specialized receptors in the eye or ear, distinct nerve connections within the visual or auditory system, and specific locations within the visual or auditory areas of the brain that receive the stimulation. The testing of the theory depended upon an individual’s report of the sensory experience (“I see red”), the nature of the stimulus to which the individual responded (a specific wavelength of the energy spectrum), and knowledge of the physiological organization
of the sensory systems. Relating the experience to the stimulus was a matter of experimental research that could be carried out with intact human beings; detecting the activity of nerves and the location of the brain to which stimulation was transmitted was possible then only with in vitro preparations of animals. Relating subjective, psychological experience to specific external stimulation was one step in suggesting how psychology might become a science.
of the sensory systems. Relating the experience to the stimulus was a matter of experimental research that could be carried out with intact human beings; detecting the activity of nerves and the location of the brain to which stimulation was transmitted was possible then only with in vitro preparations of animals. Relating subjective, psychological experience to specific external stimulation was one step in suggesting how psychology might become a science.
Psychophysics
Experiments on the sense of touch were carried out by the physiologist E. H. Weber (1795–1878), who distinguished among the feelings of pressure, temperature, and the location of stimulation on the skin. In conducting experiments in which he stimulated his own skin, Weber explored skin sensitivity and demonstrated that “on the tip of the forefinger and lips two fine compass points could be felt as two when they were less than one-twentieth of an inch apart, but if they were nearer they seemed to be one”. Not only could touch sensitivity be measured at different points on the skin, but relative sensitivity at a single point could also be measured. Placing a standard weight at a given spot on the skin and then asking for a second weight to be judged “heavier” or “lighter” showed that the amount of weight that could be judged heavier or lighter than the standard varied as a proportion of the magnitude of the standard weight. Thus, the minimal detectable difference between two weights was relative to the weights involved; for heavy weights, differences could have to be large, but smaller differences could be detected when the weights involved were light. G. T. Fechner (1801–1887), a physicist, saw in Weber’s results the possibility of relating mental events to physical events; subjective judgments about physical magnitudes could be compared to the actual physical magnitudes. Fechner had believed since his student days “that the phenomena of mind and body run in parallel” (Marshall, 1982, p. 67). His solution to the problem of relating these two aspects of the world was to make “the relative increase of bodily energy the measure of the increase of the corresponding mental intensity”. Although Fechner conceived of the possibility independently of Weber’s results, he came to realize that his speculations about arithmetic and logarithmic relations between physical and subjective magnitudes were in fact demonstrated by Weber’s observations (Adler, 1966; Marshall, 1982). Weber’s results showed that sensory judgments of magnitude formed ratios that were sufficiently regular to assume the status of a law. Fechner designated as Weber’s law the mathematical equation that stated that the increase in perceived intensity of a stimulus (the “just noticeable difference”) was, as Weber had demonstrated, a constant proportion of the intensity of the stimulus to be increased. The regularity in ratios across a wide range of intensities led Fechner to rewrite the law in terms of a logarithmic progression, with the strength ofa sensation equal to the logarithm of the intensity of a stimulus multiplied by a constant established experimentally for the sensory system under study. “Weber’s law” now typically refers to the “simple statement that the just noticeable difference in a stimulus bears a constant ratio to the stimulus”, while “Fechner’s law” typically refers to the logarithmic relationship that Fechner formulated. Fechner called the new science that he established psychophysics and developed laboratory procedures that became part of the laboratory experiments of the new psychology as well as of the physiological research on the special senses. The measurements of the smallest detectable intensity (absolute threshold) and the smallest detectable difference in intensities between stimuli (difference threshold) for the different senses were pursued by the several methods that Fechner had devised for the purpose (see, e.g., Woodworth,1938). Resolving differences in results obtained for different methods, testing psychophysical laws over a wide range of stimulus intensities, and developing scales of psychological measurement offered significant research challenges for psychological laboratories well into the twentieth century (Stevens, 1951; Woodworth, 1938).
Mental Chronometry
Johannes Müller had speculated in his Handbuch that the speed of transmission of a nerve impulse was greater than the speed of light. Helmholtz tested that hypothesis by measuring the time to react (“reaction time”) to stimuli applied to motor nerves of different lengths in a frog and found the time to be much slower than the speed of light (Boring, 1950; Hall, 1901). He extended this research to sensory nerves by measuring the time to respond by a human to a touch on the toe and a touch on the thigh and demonstrated that he time to respond was slower for the impulse that had longer to travel. Helmholtz extended the use of time to measure a sensory-motor response to include spoken responses to words, providing a measure of the time necessary to associate words or ideas. The determination of reaction times to measure the speed of mental processes was investigated by the Dutch physiologist F. C.Donders (1818–1889). Donders began with the time to make a motor response to a stimulus (simple reaction time) and then added more stimuli, each with a different response. By subtracting simple reaction time from the time taken to make the correct response to one of several stimuli, Donders believed that he had measured the time required to make a choice (Boring, 1950;Woodworth, 1938). He then recognized that his experimental procedure required not only that an observer choose a response from among the several responses possible but also that an observer detect which stimulus had been presented from among the several possible stimuli (discrimination reaction time). Using the subtractive method that he devised, Donders estimated the time for a simple reaction, the time taken to discriminate one stimulus from others, and the time taken to choose a response. The possibility of measuring the time required by mental processes appeared to have been realized, and the reaction-time experiment as well as the subtractive procedure became part of the science of psychology (for modern adaptations, see Posner & Raichle, 1994; Sternberg, 1969).
Goals & The Self.......
Another point made by the notion of hierarchical organization concerns the fact that goals are not equivalent in their importance.The higher you go into the organization, the more fundamental to the overriding sense of self are the qualities encountered. Thus, goal qualities at higher levels would appear to be intrinsically more important than those at lower levels. Goals at a given level are not necessarily equivalent to one another in importance, however. In a hierarchical system there are at least two ways in which importance accrues to a goal. The more directly an action contributes to attainment of some highly valued goal at a more abstract level, the more important is that action. Second, an act that contributes to the attainment of several goals at once is thereby more important than an act that contributes to the attainment of only one goal. Relative importance of goals returns us again to the concept of self. In contemporary theory the self-concept has several aspects. One is the structure of knowledge about your personal history; another is knowledge about who you are now. Another is the self-guides or images of potential selves that are used to guide movement from the present into the future. As stated earlier, a broad implication of this view is that the self—indeed, personality—consists partly of a person’s goals.
What is Color
In 1666, English scientist Sir Isaac Newton discovered that when pure white light is passed through a prism, it separates into all of the visible colors. Newton also found that each color is comprised of a single wavelength and cannot be separated any further into other colors. Further experiments demonstrated that light could be combined to form other colors. For example, red light mixed with yellow light creates an orange color. A color resulting from a mix of two other colors is known as a metamer. Some colors, such as yellow and purple, cancel each other out when mixed and result in a white light. These competing colors are known as complements.
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