Mechanism and contextualism in psychology

Wilhelm Wundt’s Physiologische Psychologie and Völkerpsychologie

The founding of psychology as a scientific discipline is typically dated to the opening of the first laboratory devoted to psychological research by Wilhelm Wundt in 1879 (e.g., Beenfeldt, 2013). Wundt and the students in his Institut für Psychologie conducted research using psychophysical and chronometric methods established by Gustav Fechner (1868/1966), Franciscus Donders (1868/1969), and others. This laboratory approach of controlled experimentation is associated with Wundt through what he called physiologische psychologie (sometimes translated as physiological psychology and sometimes as individual psychology), with the name reflecting his adoption of the experimental method used in physiological studies (Draaisma & De Rijcke, 2001). Danziger (1990) indicates that Wundt’s original contribution was to take the existing methods of Fechner and Donders and provide them with a psychological context. He also credits Wundt with establishing the distinction between the experimenter, who designed and conducted the experiment (usually a graduate student), and the subjects who participated in it (often Wundt and other students). As Weimer and Palermo (1973) put it, Wundt “can profitably be considered as having founded a normal science research tradition” (p. 221). The best English language source of Wundt’s original work is Outlines of Psychology (Wundt, 1902), a translation of the fourth edition of his text Grundzüge der Physiologischen Psychologie (Wundt, 1874), for which the first edition was published in 1873.

Less widely known is that Wundt advocated another approach, introduced by philosopher Moritz Lazarus and linguist Heymann Steinthal, called Völkerpsychologie (Klautke, 2019). Völkerpsychologie is translated as folk psychology, cultural psychology, or people’s psychology, and is an approach based on studying historical events, development of language, and anthropology. Although Wundt (1863) did not develop his Völkerpsychologie until well after his initial contributions to experimental psychology, the basic idea was present in his earliest writings on psychology as a second, major division along with his experimental psychology (Ferrari et al., 2010). Wundt’s view was that laboratory, experimental psychology was appropriate for studying perceptual–motor processes (although he did not consider it a natural science), but more complex cognitive and social processes had to be studied by other methods. Wundt (1916) emphasized history, anthropology, and language, but advocated using those areas as a basis for psychological inquiry rather than replacing the traditional physiological measures. He saw experimental and cultural psychology as related, with the idea that a complete view of psychology required both. Völkerpsychologie “was an essential complement to laboratory investigations of consciousness; they were two equally important branches of the modern scientific (wissenschaftliche) psychology that Wundt promoted until the end of his long life” (Ferrari et al., 2010, p. 97).

In the translator’s preface to Wundt’s Völkerpsychologie, Schaub notes the recognition received by Wundt’s contributions to physiological psychology and areas of philosophy, and offers the following opinion regarding Völkerpsychologie:

One may hazard the prophecy, however, that the final verdict of history will ascribe to his latest studies, those in folk psychology, a significance not inferior to that which is now generally conceded to the writings of his earlier years. The Völkerpsychologie is a truly monumental work. (Schaub, 1916, p. vi)

Yet, this upswell of recognition within psychological science of the Völkerpsychologie side of Wundt’s work never occurred. Although Weimer and Palermo (1973) emphasized Wundt’s experimental psychology in their article on paradigms in psychology, they mention, “Remember that Wundt himself, in rejecting associationism for the higher mental processes such as language, had ruled this area of investigation out of experimental psychology, as fit for Volkerpsychologie only” (p. 223). However, even such mention was rare. Beenfeldt (2013) more recently emphasized, as have others, “This non-experimental side of Wundt’s work, however, was, in the context of scientific psychology, all but ignored even while the experimental side attracted both attention and emulation” (p. 28). The question is, Why did Wundt’s nonexperimental work have little influence on the field of psychology?

Philosophies of Mach and Avenarius

A superficial answer to this question is that many psychologists were intent on establishing psychology as a science and, therefore, did not want to accept any approach that was not modeled after the natural sciences (Danziger, 1979). Such a view was stated strongly by Sherif (1998) who expressed concern with the

impulse of psychologists to seek acceptance and prestige for their new discipline through imitating the more established scientific disciplines. Over time, those who became the most prominent psychologists were those who imitated them most blindly, grasping what brought prestige in their society even though it was more a caricature of the more established sciences. (p. 64)

Danziger (1979) provides a more sophisticated analysis of the philosophical views that led to an emphasis on experimentation in an article titled, “The Positivist Repudiation of Wundt,” but from an essentially dismissive perspective. He concludes that Wundt’s Völkerpsychologie was not widely accepted because Wundt had lost the philosophical battle:

Two models were proposed to establish the kind of discipline that psychology was to become. First, there was Wilhelm Wundt’s model of a psychology which had at most one foot in the camp of the natural sciences, and then there was the second model for which psychology was wholly a natural science. It was this second model which proved historically victorious. (p. 205)

The second model to which Danziger (1979) referred can be found in the philosophies of science from Ernst Mach (a scientist) and Richard Avenarius (a philosopher), whose views on science and psychological science influenced the psychologists who “repudiated” Wundt, including Hermann Ebbinghaus, Oswald Külpe, and Edward Bradford Titchener. Mach (1886/1914), the better known of the two, acknowledged personal experience as being of “high practical importance, not only for the individual, but for the entire species” (p. 23). He went on to state that in “cases, however, in which practical ends are not concerned, but where knowledge is an end in itself,” a focus on personal experience “may prove to be insufficient, obstructive, and untenable” (p. 23). In other words, Mach’s position with regard to dualism of the physical and the psychical was: “This dualism is to my mind artificial and unnecessary” (p. 41).

Mach (1886/1914) opposed what he called metaphysical explanations that are not grounded in experience (Guzzardi, 2021). He stressed that explanatory difficulties disappear:

when we look at the matter as it were in a mathematical light, and make it clear to ourselves that all that is valuable to us is the discovery of functional relations, and that what we want to know is merely the dependence of experiences on one another. (Mach, 1886/1914, p. 35)

For example, Guzzardi (2021) notes that Mach sees Fechner’s view of science as including a metaphysical substrate whereas his does not. Likewise, Mach (1886/1914) indicates that he does not use the phrase “the will” to mean “any special psychical or metaphysical agent, nor do I assume a specific psychical causality” (p. 171). By not invoking a metaphysical realm, Mach opposes Wundt’s incorporation of folk psychology. Mach goes on to say, “Rather, I am convinced, in company with the overwhelming majority of physiologists and modern psychologists, that the phenomena of volition must. . . be explained by means of the physical forces of the organism alone” (p. 71). These statements illustrate that Mach considered psychological science to be distinct from the everyday, personal experiences of persons.

Avenarius is less well-known than Mach, in part due to the complexity of Avenarius’s writings (Kodis, 1896; Mach, 1886/1914). Avenarius’s most influential works are Kritik der reinen Erfahrung (Critique of Pure Experience, 1890); see Carstanjen, 1897) and Der menschliche Weltbegriff (The Human Concept of the World, 1901; see Russo Krauss, 2019).

Avenarius called his philosophical view empiriocriticism, which Carstanjen (1897) notes:

takes up the position that everything is experience when it has been stated as experienced by an individual—though it may be that primarily it is only experience for this one individual in question. . . But then we investigate the difference between this concept of experience which is valid for the individual and the concept of experience which is universally valid. (p. 451)

Carstanjen (1897) goes on to say,

Empiriocriticism… approaches its task purely speculatively…, although it builds entirely upon the results of the natural sciences. This speculative character may be frankly conceded without fear of confusion with the speculative method of metaphysics. The speculation in the empiriocritical theory does not extend to the contents of knowledge and experience, but to their universal form. (p. 451)

Russo Krauss (2019) explains the implication as follows: “This means that psychology should not study the experience as it is lived in the first-person, but the experience as it is observed in the third-person” (p. 26).

Avenarius’s emphasis was on establishing functional relationships without an a priori assumption of causality or of a soul. Carstanjen (1897) remarks:

To Avenarius the important point was the methodological need, that just as we are able to think of the lower organised nervous systems as functioning without consciousness, so also we should be able to think of all human doing and striving, all action and thought, imagination, hope and love, without immediately invoking a spirit in explanation. (pp. 465–466)

In other words, a self-contained, natural science approach to psychology should be possible.

In his last book, Avenarius (1901) developed his argument around the fallacy he called “introjection.” Avenarius assumed that the natural world provides constituents of the “self” that are comparable to those of the environment. This allows “delimitation of the complex ‘self’ and the complex ‘environment’ to be carried out without necessarily involving the ‘dualism’ of ‘body’ and ‘soul’” (Wlassak, as cited in Mach, 1886/1914, p. 51). Again, according to Avenarius, psychology is explainable in terms of natural science, and it is a fallacy to invoke psychical concepts that go beyond it. Russo Krauss (2019) summarizes the critical point of Avenarius’s arguments as follows:

The real problem of introspection is… the impossibility for the single man [sic] to observe upon what his own experience depended. For this reason, the experiment is not just mere support for introspection, it is the only way we can observe this dependency, and therefore the first and foremost method of psychology. In the light of the above, we can affirm that Avenarius transformed a methodological innovation (the increasing use of experimental research) into a new epistemological foundation of psychology. (pp. 27–28)

Mach (1886/1914) pointed out that, in regard to Avenarius, “It is to our agreement in the conception of the relation between the physical and the psychical that I attach the greatest importance” (p. 50). Avenarius, in harmony with Mach, differentiates “physical” from “psychological” (and not “psychical”, unlike Wundt). Mach concludes his chapter on Avenarius with the opinion, “When I contemplate the close coincidence between general philosophical views [Avenarius] and the views of scientific specialists [Mach], I think I am justified in detecting here a hopeful presage of the mutual accommodation of the sciences to one another” (p. 56).

Ebbinghaus, Külpe, and Titchener

Danziger (1979) indicated that the psychologists who repudiated Wundt—Ebbinghaus, Külpe, Titchener, and others—and took a strong mechanistic, natural science approach were influenced by the philosophies of Mach and Avenarius. In 1885, Ebbinghaus made a compelling case that the method of natural science—experimentation and quantification—could be applied to the study of higher level psychological processes. Ebbinghaus’s (1885/1964) monograph, Über das Gedächtnis (Memory: A Contribution to Experimental Psychology) included many detailed memory experiments on himself as the subject, analyzed systematically and quantitatively. The first paragraph of the author’s preface makes it clear that he does not accept that the experimental method is restricted to basic perceptual and motor processes. He states:

In the realm of mental phenomena, experiment and measurement have hitherto been chiefly limited in application to sense perception and to the time relations of mental processes. By means of the following investigations, we have tried to go a step farther into the workings of the mind and to submit to an experimental and quantitative treatment the manifestations of memory. (p. xiii)

Woodworth (1909) stressed the importance of Ebbinghaus’s memory research, stating, “His demonstration that so central a process as memory could be studied by exact methods added greatly to the courage of the young science, and his work was the starting-point for a large and steadily increasing literature” (p. 254).

Russo Krauss (2019) summarizes Ebbinghaus’s general views of psychology presented in his 1902 book, Grundzüge der Psychologie (Principles of Psychology, Ebbinghaus, 1902), and how they are related to those of Mach and Avenarius. The best English language source of Ebbinghaus’s views is the “free translation” of his 1908 book, Abriss der Psychologie (Outline of Psychology; Ebbinghaus, 1908a), by Max Meier, published as Psychology: An Elementary Textbook (Ebbinghaus, 1908b). In it, Ebbinghaus (1908b) advocates a natural science approach to psychology, noting that an obstacle to it is people’s everyday experiences: “However difficult it may be to investigate the nature and causal connections of mental phenomena, everybody has a superficial knowledge of their external manifestations” (p. 4). He asks a question of what circumstances have made it possible to overcome such obstacles, to which he answers, “There are many; but in the end they all lead back to one: the rise and progress of natural science since the sixteenth century” (p. 6). Ebbinghaus emphasized that an important fruit of the first advancement of natural science was “the idea of the absolute and inevitable subjection to law of all mental processes, which I have just said forms the foundation of all serious psychological work” (p. 7). A sentence from Woodworth’s (1909) obituary for Ebbinghaus captures the main point: “He insisted that the problems and methods of psychology were of the same general sort as those of natural science” (p. 256). Rather than Ebbinghaus’s philosophy, experimental psychologists were more impressed with his research on memory, with Roediger (1985) emphasizing in a 100th anniversary review of Ebbinghaus’s Über das Gedächtnis that it “records some of the most remarkable research achievements in the history of psychology” (p. 519).

Among Wundt’s students Külpe and Titchener, Russo Krauss (2017, 2019) argues that Avenarius was much more influential than Mach on their philosophical development. The reason is that Avenarius was a colleague of Wundt’s at Leipzig whose philosophy of science initially aligned with the views of Wundt and his experimental work in psychology. However, Avenarius later split from Wundt, developing his philosophy in a direction that extended the naturalistic approach and experimental psychology much further than Wundt thought it should be, while Wundt was evolving an increasing role for Völkerpsychologie. Külpe and Titchener were well-versed in Avenarius’s philosophy and developed their philosophies of science and psychology from it. In their philosophies, the natural science approach to psychology was self-contained and did not need to be combined with the Völkerpsychologie to provide a complete view.

Külpe was Wundt’s Institute assistant from 1886–1894, at which time he was hired as a professor at the University of Würzburg. There, he established an influential psychology research group which became known as the Würzburg School. Before the move, in 1895, Külpe published the book, Grundriss der Psychologie (Outlines of Psychology; Külpe, 1895/1901). In the introduction, Külpe (1895/1901) provides a list of points under the heading “Meaning and Problem of Psychology,” the second of which is: “The facts with which science in general, apart from philosophy, has to deal we term facts of experience” (p. 1). His third point includes the statement, “there is no single fact of experience which cannot be made the subject of psychological investigation” (p. 2). Külpe continues, saying,

We must look for the distinctive character of psychological subject-matter not in the peculiar nature of a definite class of experiential facts, but rather in some property which attaches to all alike. This property is the dependency of facts of experience upon experiencing individuals. (p. 2)

Külpe (1895/1901) makes apparent in his fourth point that one implication of his view is that it is misleading to say that psychology is a science of “‘psychical’ facts, facts of ‘consciousness’” (p. 3). Later, he states, “The psychologist understands by a theory precisely what is meant by the term in natural science: the specification of the conditions of the appearance of a given phenomenon” (p. 6). After discussing the applicability of the experimental method to sensation, feelings, and bodily movements, Külpe continues:

But more than this: we have a number of ingenious devices for the experimental investigation of the connections of mental processes with one another. So that in principle there is no topic of psychological inquiry which cannot be approached by the experimental method. And experimental psychology is, therefore, fully within its rights when it claims to be the general psychology of which we propose to treat (I. II). (p. 13)

We intentionally left in the reference to section I. II in Külpe’s (1895/1901) chapter because he makes clear in it that he does not include social psychology in what he calls general psychology “because the mental processes dependent upon communities of men [people] are only realized in individuals and only expressed by individuals” (p. 7). Indeed, Külpe and his students are known for extending the use of introspective methods in experimental psychology to mental processes, including task set and problem solving. Külpe’s philosophical position and expansion of introspection to mental processes runs counter to Wundt’s view that only perceptual and motor processes could be investigated experimentally.

Külpe (1895/1901) noted that the view of psychology he advocated, which he called “experimental and psychophysical,” differed from a second view, which he called “descriptive and metaphysical” (p. 23). He was explicit that the experimental and psychophysical approach provides “the only practicable road towards a real explanation of the facts of mind” (p. 23). Külpe (1912) returned to discussing the alternative views in a later article, “Contribution to the History of the Concept of Reality.” In it, he mainly emphasizes that they are based on alternative views of reality. Fossa (2018) emphasizes, of Külpe’s (1912) distinction between views, “This distinction has constituted a difference… within psychology, specifically between the current scientist—mainstream research—and the cultural historical socioconstructivist perspective” (Fossa, 2018, p. 91). Külpe (1912) concludes his article stating, “The truth remains, as we have pointed out, that in all sciences of fact, psychology and the humanistic disciplines included, reality is postulated and determined” (p. 10), indicating that analysis of this remains a significant philosophical task.

Titchener attended the university at Leipzig for 2 years, from fall 1890 to fall 1892, working in Wundt’s Institute and obtaining his Ph.D. He had a close relationship with Külpe in the latter’s role as Institute assistant. Külpe taught courses in which Titchener was a student and oversaw most of the experimental research that the students were conducting at the Institute (Evans, 2023). Therefore, it is not too surprising that Titchener’s views on science were similar to Külpe’s, a point made by Tweney (1987): “Külpe’s use of experimental methods to approach problems like attention and imagery and his positivism differed radically from Wundt’s views, but were embraced by Titchener” (p. 38).

Titchener is also known for favoring a natural science approach to psychology that stressed laboratory experiments under controlled conditions, with his theoretical approach being what is called structuralism. But Tweney (1987) stresses, “Titchener was data-oriented rather than theory-oriented” (p. 39). Much of the research published from his lab focused on experimental studies of emotion and attention, in disagreement with Wundt.

Titchener’s (1929/1972) posthumous book, Systematic Psychology: Prolegomena, presents his philosophy of science and psychology most completely, in which he advocated an experimental approach. In it, he distinguished the worldviews of science, technology, and common sense (see Table 1). The aims, attitudes, and objects of psychological science differ from those of what Titchener called common sense psychology. Titchener describes common sense as “the very antipodes of science” (p. 48), for which logic is bound but not necessarily characteristic of scientific findings. Technology is intermediate: while it utilizes scientific facts, it is a distinct approach that is closer to common sense in aims and attitudes than those of science. Russo Krauss (2019) emphasizes that she placed Titchener at the end of her chapter discussing the philosophies of Ebbinghaus and Külpe “because his Systematic Psychology represents the culmination of the debate, insofar as it is the last contribute [contribution] to it and also a synthesis of the discussion” (p. 90).

OPEN IN VIEWER

Table 1.

Titchener’s schema of three categories of world experience.

	Science	Technology	Common sense
Object	Facts	Fact-values	Values
Attitude	Disinterested (Impersonal)	Interested (Personal)	Interested (Personal)
Aim	Understanding	Utilization	Utilization

Note. From Evans and MacLeod (1972, p. 272).

Danziger (1979, 1990) provides a rather negative view of Titchener’s depiction of science and technology. For example, he says that Titchener “denigrated the practice of his opponents as being not science but technology” (Danziger, 1990, p. 11), citing Titchener (1914). Yet, in a 1914 article, Titchener (1914) explicitly says that he “has no desire… to attempt any sort of disparagement of technology” (pp. 21–22), after which he makes his point that science and technology are different and should not be conflated.

Külpe’s and Titchener’s repudiation of Wundt seems quite reasonable when put in light of the philosophical lineage provided by Russo Krauss (2017, 2019). For example, Mach (1886/1914) describes his and Avenarius’s views as self-evident: “What Avenarius puts forward, and consequently what I also put forward, appears to me to contain scarcely anything that is not self-evident” (p. 56). Moreover, the research programs of Külpe and his students built on those propositions made contributions to the understanding of thought processes through their research on task set, or determining tendencies, prior to onset of stimuli to which a person responds and on directed thinking. Titchener (1908) remained closer to Wundt in his structuralism, but he made many advances in the study of attention, including identifying the law of prior entry, which has been confirmed and extended in the 21st century (Spence & Parise, 2010).

As noted, Mach pointed out the similarity of his views as a scientist with those of Avenarius, a philosopher. Moreover, Russo Krauss (2019) stated, regarding Avenarius, “his mature view on psychology can be considered more advanced than the Wundtian one” (p. 7). Contrast this statement with Danziger’s (1979) conclusion about Wundt that “it must be recognized that his system had been a failure, even on its own terms” (p. 225), which he enumerates in the sentences that follow it in his book. The emphasis on natural science and experimentation by Ebbinghaus, Külpe, and Titchener was based on thorough philosophical analyses of science and psychological science, inspired by Avenarius, and on empirical evidence that the experimental method could be extended to higher levels of cognition and behavior than Wundt thought possible. Contrary to the opinion expressed by Danziger and others, the natural science emphasis of Ebbinghaus, Külpe, and Titchener was logically and empirically defensible.

The behaviorist, gestaltist, and cognitivist schools

Beginning with John B. Watson’s (1913) behaviorist manifesto, “Psychology as the Behaviorist Views It,” psychology in the United States turned to an emphasis on various forms of behaviorism and neo-behaviorism. Among other things, copious research was conducted on rats, pigeons, and other non-humans, with an emphasis on experimental control and objective behavioral measures. Much of the research focused on learning theory. However, other research that was based for the most part on the natural science approach prospered in the period between behaviorism’s advent and the middle of the 20th century, as illustrated in the handbooks by Woodworth (1938), Stevens (1951), and Osgood (1953). In Europe, Max Wertheimer’s (1912) publication, “Experimentelle Studien über das Sehen von Bewegung” (“Experimental Studies of the Perception of Movement”) initiated the Gestalt School of psychology, which focused on perceptual experience and problem-solving (Köhler, 1917/2019; Wertheimer, 1945), countering the views of Külpe and Titchener and of the behaviorists. It originated in Germany but then moved to the U.S. in the 1930s when the Gestalt psychologists migrated there (Sokal, 1984).

Although Gestalt psychology was influential in many ways (Rock & Palmer, 1990), the theoretical views developed by researchers associated with Külpe and the Würzburg school in his later years and after his death seem to be more closely related to contemporary cognitive psychology. Karl Bühler extended the experimental methods of the school to include more complex questions and longer interval periods to answer, providing detailed analyses of the reported conscious experiences. In addition to his investigations of thinking, prior to emigrating to the U.S., Bühler studied language and motivation from a cognitive perspective. In a symposium in honor of Bühler shortly after his death, the social–personality psychologist Gardner Murphy remarked, “At Vienna during the 30 years in which he served the university, he was a landmark of concern with higher phenomena, especially those of a cognitive character” (as quoted in Bugental et al., 1966, pp. 193–194). Otto Selz (1924) is considered to be the progenitor of contemporary cognitive psychology. He made theoretical advances in the analysis of creative thinking that were precursors to the developments in the psychology of thinking and expertise that occurred in the “cognitive,” or information-processing, revolution that began in the 1950s (Proctor & Ridderinkhof, 2022; Simon, 1981).

What we are calling the mechanistic science approach, with emphasis on experimentation and causal explanations, has been even more successful since the cognitive revolution of the 1950s. Due in part to the interaction of psychologists with state-of-the-art technology being developed by engineers during World War II and shortly thereafter, various areas of psychology and other disciplines converged in adopting an information-processing approach, broadly defined (Posner, 1986). The developments are described in detail in other places (Proctor & Vu, 2010; Xiong & Proctor, 2018), so we will just emphasize key points here. The first point is that much of the impetus came from researchers engaged in engineering psychology, or human factors, that developed contemporaneously (Fitts, 1958). Various research topics in attention, response selection, and motor control were motivated in part by applied issues. A second point is that the developments were interdisciplinary. Many of the concepts used in psychology research came from systems theory and the realization that processes at various levels could be studied from an information-processing perspective (Posner, 1986). Ideas from communication engineering and computer science were incorporated into analysis of human perception, cognition, and action.

Another factor whose impact cannot be overstated is the widespread adoption of group experimental designs and statistics. Although Fisher (1925, 1935) and Neyman and Pearson (1928, 1933) had introduced the concepts earlier, psychologists began to apply them intensively in the 1950s. Specifically, the experimental design methods advocated by Fisher, along with null hypothesis significance testing to evaluate group mean differences, altered the nature of much experimental research that was conducted. The statistical methods also provided the decision–theoretic basis for applying probabilistic analyses to a wide range of psychological phenomena (Rosenblatt, 1958; Tanner & Swets, 1954). On most accounts, the human information-processing approach, broadly defined, would be considered successful, as it is still flourishing today.

Other attempts at unifying natural science with cultural–historical psychology

Wundt was unable to convince most researchers that laboratory experimental psychology should be combined with his Völkerpsychologie for a unified approach in psychology. Indeed, Ferrari et al. (2010) state, “Although Wundt and his colleagues in Leipzig devoted a great deal of attention to both of these areas, they failed to make dynamic links needed to unite the ‘two enterprises’” (p. 100). However, their article emphasizes that two similar attempts at a unified psychology were made by Lev Vygotsky and Albert Bandura.

Beginning early in his career, Vygotsky stated that consciousness should have a central role in psychological theory (Ferrari et al., 2010). According to Vygotsky (1997), “Scientific psychology must not ignore the facts of consciousness but materialize them, translate them into the objective language of the objectively existing… Consciousness is the problem of the structure of behavior” (p. 67). He emphasized historical experience, the experience of prior generations, and social experience, the experience of other people. Vygotsky (1997) identified a third type of experience, called doubled experience, which he illustrated as follows: “In the movements of the hands and the transformations of the material, labor repeats what was first, as it were, done in the worker’s imagination with models of these movements and this same material” (p. 68). Thus, “the new part of the formula of human behavior looks like this: historical experience, social experience, and doubled experience” (p. 69).

From this analysis, Vygotsky (1997) concluded:

Psychology must state and solve the problem of consciousness by saying that it is interaction, the mutual influence and stimulation of various systems of reflexes. Conscious is what is transmitted in the form of a stimulus to other systems and elicits a response in them. Consciousness is always an echo, a response apparatus. (p. 72)

He emphasized that one implication of this is that thought acts and consciousness of them need to be distinguished, relying on the investigations of Külpe and the Würzburg psychologists: “One of the conclusions of these investigations establishes the inobservability of the thought act itself, which escapes perception” (Vygotsky, 1997, p. 76). In other words, thought can be “imageless.” Vygotsky is also of the opinion that “the mechanism of social behavior and the mechanism of consciousness are one and the same. Speech is, on the one hand, the system of the ‘reflexes of social contact’ … and, on the other hand, the system of the reflexes of consciousness par excellence” (p. 77). This last quote conveys his view that social–cultural factors are foundational in psychology, similar to Wundt, with speech being the unique process of human consciousness.

Van der Veer and Zavershneva (2018) describe Vygotsky’s views as follows:

His fundamental claim was that human beings differ from other animals in that they acquire cultural means that radically restructure their behavior and cerebral organization. The most fundamental cultural means is language…, which makes it possible to transcend the here and now and to solve problems on a theoretical plane. Because language and cultural tools differ per culture Vygotsky believed it possible to find cross-cultural differences in intellectual development. (p. 101)

Ferrari et al. (2010) characterize Vygotsky’s writings in the 1930s, near the end of his life, as follows:

These writings show that Vygotsky had advanced beyond Wundt’s program for a complete psychology as a science of consciousness. Where Wundt merely claimed the priority of Völkerpsychologie in shaping individual consciousness, Vygotsky indicated how research might proceed in explaining how the collective becomes personal. (p. 107)

Albert Bandura was a social psychologist known for his early work on social learning theory (Bandura, 1977) and his research on self-efficacy and adolescent aggression (Bandura, 1997). In the mid-1980s, he developed what he called social cognitive theory, which was a more holistic theory of human cognition in which he emphasized perceived self-efficacy (Bandura, 1986). Ferrari et al. (2010) note, “As for Vygotsky, Bandura claims that reflective self-consciousness is the hallmark of human agency” (p. 109). Bandura specifically challenged the view that the science of consciousness can only be studied through subpersonal information-processing that does not include personal agency, in other words, he advocated studying consciousness through personal thought and experience. Ferrari et al. (2010) point out that,

Like Wundt and Vygotsky earlier, Bandura (2006) considers the evolution of the human capacity to use language to be critical in developing an encultured higher human consciousness that allows us to be true psychological agents within our social communities. True, the specifics of Bandura’s work are unique, but the spirit of the theory is very close to that of Vygotsky in that it emphasizes self-regulation and self-mastery. Like Vygotsky, Bandura is also interested in how people can take charge of their own behavior; however, Bandura adds an important notion that had not yet been introduced by Wundt or Vygotsky – that our own estimates of our capacities have a profound effect on our actual agency. (p. 111)

In his 2002 article, “Social Cognitive Theory in Cultural Context,” Bandura (2002) stated, “Among the mechanisms of human agency none is more central and pervasive than beliefs of personal efficacy” (p. 270), which relates to his prior work. A sentence later, he said, “Self-efficacy beliefs regulate human functioning through cognitive, motivational, affective, and decisional processes” (p. 270), that is, through fundamental psychological processes. Most important, Bandura (2002) emphasized that efficacy beliefs are not confined to the individual but are influenced by group actions through what he called collective efficacy: “Perceived collective efficacy enhances group functioning just as personal efficacy enhances individual functioning” (p. 271). Moreover, perceived collective and self-efficacy are not only influenced by the culture, but the actions taken in turn affect the culture. Ferrari et al. (2010) conclude:

And it is in this way that Bandura’s theory has become cultural–historical in the sense proposed by Wundt and Vygotsky, since both personal and collective agency shape the development of culture by influencing specific knowledge domains and, more generally, language, myths and customs. (pp. 109–110).

Bandura ends his 2006 article by advocating a unified psychology:

Psychology is the one discipline that uniquely encompasses the complex interplay among biological, intrapersonal, interpersonal, and sociostructural determinants of human functioning. As a core discipline, it is especially well suited to advance understanding of the integrated biopsychosocial nature of humans, and how they agentically manage and shape the everyday world around them. (Bandura, 2006, p. 177)

In concluding their article, Ferrari et al. (2010) argue that the fact that sociocultural psychology keeps recurring in the history of psychology suggests that there is “something essentially important about a cultural-historical approach to the science of consciousness. At the very least, such an approach broadens our understanding of conscious human experience beyond simple biological processing or individual learning and development” (p. 113).

The treatment of psychology

One cannot disagree that being familiar with alternative views of human experience and behavior broadens our understanding. A fundamental question, though, is which worldview is needed to continue developing psychology as a field of research. Wundt, Vygotsky, and Bandura argued that there is value in a contextualist worldview. In contrast, Mach, Avenarius, Ebbinghaus, Külpe, and Titchener concluded that a mechanistic worldview is needed to develop and continue psychology as a natural science. Our position is closest to theirs because the two approaches are grounded in distinct worldviews, as described through the historical context of psychology.

The quotes with which we began the chapter illustrate the dissimilar goals of those who subscribe to qualitative inquiry (like Willig, 2012/2023) rather than to psychological science as it is typically understood (like Steiner et al., 2012/2023): descriptions of experience as opposed to causal explanations. The goals are incommensurable and arise from the worldviews of contextualism and mechanism, respectively. As noted, these worldviews correspond, respectively, with contextualism and mechanism, two of four worldviews that the philosopher Stephen Pepper (1942) identified as being “relatively adequate.” (The other two, formism and organicism, are not considered here.) Pepper notes, “Mechanism has for several generations been particularly congenial to scientists” (p. 110). Although there have been debates as to how to define mechanism, the statement still seems to be true in the broad sense defined by Illari and Williamson (2012): “A mechanism for a phenomenon consists of entities and activities organized in such a way that they are responsible for the phenomenon” (p. 123).

Specifically, Pepper (1942) noted:

There is also a very strong tendency for mechanism and contextualism to combine… The two theories are in many ways complementary. Mechanism gives a basis and a substance to contextualistic analyses, and contextualism gives a life and reality to mechanistic syntheses… Yet, mixed, the two sets of categories do not work happily, and the damage they do to each other’s interpretations does not seem to me in any way to compensate for the added richness. (p. 147)

These characterizations are not only weaknesses but inevitable consequences of differences in the worldviews of contextualism and mechanism. Given the disparate goals of the different worldviews, we argue that the historical development of psychology supports the notion of treating psychology as a natural science through the mechanistic worldview.

If one accepts our conclusion that the mechanistic worldview followed by most psychological researchers is fundamental in the history of psychology, where does that leave us with respect to the question, Should psychology follow the methods and principles of the natural sciences? Clearly, we are of the view that experimentation is central to science in general and to psychology. Philosopher Michael Strevens (2020) poses two big questions in his book The Knowledge Machine, the first being How does science work and why is it so effective? His answer to the question is that science follows what he calls the iron rule: (a) strive to settle all arguments by empirical testing and (b) to conduct an empirical test to decide between a pair of hypotheses, perform an experiment or measurement, one of whose possible outcomes can be explained by one hypothesis (and accompanying cohort) but not the other (pp. 9, 96).

This iron rule fits most closely with how psychological research is conducted from the mechanistic worldview, and one could label it “natural science” in that regard. To our minds, evidence for the value of the products of this approach has been demonstrated outside the laboratory particularly in the area of human–machine and human–technology interactions. From the outset of the information-processing revolution in the late 1940s and 1950s, applications to the design of technology have been interwoven with basic research on the nature of human information processing. It is not only chance that the applied field of human factors engineering developed simultaneously with the basic research field of cognitive psychology. The basic research conducted from the mechanistic worldview has established methods, principles, and models that have informed design issues as new technologies developed from the mid-20th century to the present to enhance the usability and safety of the technologies.

Strevens’s (2020) second big question is Why did science arrive so late? By late, he is referring to its arrival in the 17th century. His answer is that the iron rule is “irrational.” More completely, “It seems to all the world, that there is something about the nature of science itself that the human race finds hard to take on board. That, I believe, is the answer: science is an alien thought form” (p. 4). Specifically, focus on a minute phenomenon or issue in empirical research, often for many years, does not seem rational.

Despite the many contributions of the mechanistic worldview to the field of psychology, by its nature it is not oriented to addressing the personal experiences of individuals in the physical world (Chemero & Turvey, 2007; Chong & Proctor, 2020). Whether the qualitative, descriptive research conducted from that worldview should be regarded as science is an open question. There is no doubt, though, that the type of knowledge gained from it is different from that obtained when taking a mechanistic worldview. We, as experimental cognitive psychologists, work with engineers and computer scientists on a variety of research problems related to human performance and usability of designs, but not with sociologists or anthropologists. Regardless of the terms used, mixing the concepts developed in one worldview with those in another worldview has not been deemed practical for psychology, regardless of which approach one adopts or whether one moves between worldviews. Thus, although history has shown many individuals who have advocated for different worldviews, our conclusion is that a causal, experimental goal is essential to the treatment of psychology as a natural science.