The field of psychology first emerged as a branch of philosophy, and it continued to remain so until the middle of the 19th century (cf. Fuchs & Evans, 2013, pp. 4–5). Psychology has since drastically gained in importance as the scientific discipline that inquires human behaviour and thought, and yet, institutions and scholars are not in agreement on whether and how psychology should be categorized as a scientific discipline. Such can be seen on how some universities lead their institute of psychology under the umbrella of the natural sciences (e.g., HU Berlin), while others lead it under the faculty of philosophy and humanities (e.g., University of Zurich). In the following essay, I argue that while the discipline of psychology as a whole should be categorized as a social science, its subfields such as experimental psychology, cognitive neuroscience and clinical psychology should be judged independently. Key arguments of select scholars on what broadly defines the natural and social sciences and in what way psychology fits either of the two are discussed.
History, Present, and Future
In his letter to Raumer dated back to 1816, Hegel wrote: “The concrete [universal] divides into natural philosophy, which gives only part of the whole, and the philosophy of spirit, which comprises — beyond psychology along with anthropology and the teaching of law [Recht] and duties — aesthetics and the philosophy of religion” (p. 341). Since then, psychology has long emancipated itself from the philosophy of spirit, first launching with the aim of becoming an independent scientific discipline. However, this happened not without resistance, Kant being one of various well-respected scholars reluctant to accept this change in affairs:
An empirical psychology of mental content could not … 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.” (Fuchs & Evans, 2013, p.3)
After Wilhelm Wundt’s opening of what is known as the first experimental psychology laboratory in 1879, psychology slowly strengthened its status as an experimental scientific discipline (Fuchs & Evans, 2013, p. 1). While an array of events contributed to this, I would like to mention two in particular: First of all, Wundt, among other things, focused on measuring reaction time as an indicator for the duration of mental processes, demonstrating that introspection was not the only tool fit for studying aspects of human psychology — time, no matter whether on a millisecond timescale, was accepted to be a quantifiable measure through timekeeping (“History of timekeeping devices”, in Wikipedia, n.d.). Secondly, with the addition of Galton’s and Pearson’s statistical methods towards the end of the 19th century, which were explicitly created for analytical purposes such as comparing groups of individuals (Fuchs & Evans, 2013, pp. 10–11), Kant’s originally valid points of criticism — failure to mathematically describe, quantify and experimentally manipulate — were now negligible. Nevertheless, psychology lacking objectivity due to the observer distorting the observation proved to be a more persistent notion — in fact, until today, it is believed to be one of the key distinctions between the social and natural sciences. Accordingly, many scholars have made arguments in regard to this distinction, of which I would like to discuss two, the first being posited by Jerome Kagan:
Most natural scientists hold a condescending view toward social scientists whose evidence is based on human judgments, for example, judges’ ratings of the meaning of a behaviour or a verbal report. But, as noted earlier, particle physicists often rely on the consensual judgments of experts poring over the evidence produced by a linear accelerator. Thus, the nineteenth-century distinction between objectively and subjectively based evidence has become somewhat fuzzier in modern physics laboratories. Each recording device, whether a human or a machine, registers different information, and the evidence from either device often requires consensual agreement among experts to determine meaning and validity. (Kagan, 2009, p. 82)
So, even if an “objective” entity (e.g., a machine) gathers the data, any one of the steps that follow will inevitably involve human beings, since evaluated data still needs to be interpreted, for which — to my knowledge — there exists no machine yet. Needless to say, it is those same human beings doing the interpreting which inevitably come with flawed human judgment, which in turn makes up the “subjectivity” the natural sciences seek to avoid.
There is an important premise that needs to be pointed out here: In his essay Die Logik der Sozialwissenschaften, the academic and philosopher Karl Popper argues why it is misled to assume that objectivity of science relies on the objectivity of the operating scientist. In the eleventh of the text’s 27 theses, he mentions that the natural scientist is just as partial in favouring his own ideas and theories as all other human beings: Some of the most excellent contemporary physicists have founded schools of thought that are explicitly geared towards opposing any new ideas. Popper follows up with what is his twelfth thesis, where he notes that what is considered scientific objectivity lies solely in the tradition of criticism, and that it is this tradition which allows for the prevailing dogma to be criticized against all resistance. In other words, the objectivity of science is not an individual matter, but rather a matter of mutual criticism — the act of scientists distributing the work, keeping each other on their toes, ultimately working together and against each other at the same time (“Die Logik der Sozialwissenschaften”, 2017, p. 221).
However, for the sake of argument, let’s consider Popper’s claim inadmissible, and assume that objectivity of measurement is indeed only founded in the operating scientist, respectively the tool at hand — this would require for the discipline of psychology to be in possession of a tool that is the equivalent of the linear accelerator from physics, like Kagan mentions. We are in luck: Roughly two decades ago, around the turn of the millennium, the methods of neuroimaging achieved a massive breakthrough. Functional magnetic resonance imaging (fMRI) provided a novel way of capturing changes in blood flow in the brain, and so cognitive abilities could be directly observed from a perspective never seen before: Instead of having to heavily rely on surface-level phenomena such as visible emotion or physical response, there was now a refined way of gathering data on what happens beneath the surface during those same processes (“Functional magnetic resonance imaging”, in Wikipedia, n.d.). Not only did these methods prove to be useful in various disciplines like psychology and medicine, but with its biophysical basis, experts from the natural sciences — especially physicists — were now much needed in associated scientific projects and studies, leading up to much interdisciplinary collaboration.
Besides further blurring the line between psychology as a social science and the “higher” standards of natural sciences, this recent development underlines another point: Psychology can hardly be seen as a unified, homogenous field anymore. As an academic discipline, it encompasses a vast range of subfields, from neurocognitive psychology and psychophysics to social psychology and media psychology. As human behaviour and thought by definition is embedded in anything that involves humans, psychology as an applied practice also picks up on many facets of human society such as delinquency (criminal psychology), work (industrial and organizational psychology) and mental health (clinical psychology and psychotherapy). This begs the question: Is it even warranted to judge psychology as an entire discipline anymore?
On this note, I would like to go into two more scholars’ views. Professor Billman-Mahecha, a scholar of psychology, argues that “methods do not serve to unify the psychological discipline”. According to her, methodological questions seem to have become a matter of identity, holding more weight than the underlying theoretical positions and the kind of questions that are inquired in the field. In the 20th century, a divide was sparked, a tug of war between natural sciences and humanities, objectivity and subjectivity, nomothetic and idiographic, and most recently, quantitative and qualitative. She notes that while psychology has developed a few notable methods of its own such as test theory in psychometrics, most of them have been adopted and adapted from other fields, concluding that the further methodological development of psychology will not contribute to its unity in any way (Billmann-Mahecha, n.d., p. 124). Thus, the answer in how the field should be categorized must lie elsewhere.
Fortunately, in the same text previously cited in this essay, Popper also dissolves some of this tension, providing a convincing argument as to why it makes sense to categorize psychology as a social science: Human thinking and behaviour largely depends on social context — for example, a) imitation, b) language, and c) family are all social categories, as they rely on a) another being providing a basis for imitation, b) another being being there to converse with and c) a group of beings existing for them to be able to stand in relation to each other. According to Popper, it is clear that the psychology of learning and thinking, but also psychoanalysis, would be impossible without any one of the aforementioned: For example, a readily available opposite is vastly important to learning and thinking (e.g., Dautenhahn & Nehaniv, 2007), and psychoanalysis necessitates the client expressing their thoughts in language. This means that psychology presupposes societal terms, and it logically follows that it is impossible for psychology to completely explain society and its phenomena on its own. Now, what represents the study of society are the social sciences, but as we just established, psychology cannot be seen as the fundamental science of it — the social sciences do not rely on psychology. On the other hand, however, psychology does depend on the social sciences: The social categories that it presupposes are founded in concepts of the social sciences, and so the social sciences must be fundamental to psychology.
Consequently, I propose that in universities and academia, institutes of psychology and the field as a whole should be led under the umbrella of the social sciences. In light of the vast range of psychology subfields and the ongoing methodological divide, each subfield in question should however be judged on its respective employed methods and theoretical foundations: For example, while the cognitive neurosciences — with methods such as fMRI — adhere to the principles and standards of the natural sciences, social psychology with its use of qualitative tools and strong societal orientation is more in tune with the study of the social sciences.
Both the history and present of psychology are characterized by a lack of clear belonging and unity. The field started out as a branch of philosophy and weathered the storm of criticism from scholars such as Darwin, finding ways of quantifying as well as experimentally manipulating human thought and behaviour. As it evolved into an independent experimental discipline, the standard of objectivity remained hard to live up to, but Popper’s questioning of the concept of objectivity as well as recent methodological advances in neuroimaging methods increasingly blur the line — what is left is the question of what the underlying difference between the natural and social sciences as a whole really is. While psychology ended up being a multi-faceted study encompassing many applied and theoretical branches, its foundation presupposes concepts from the social sciences, while the social sciences do not presuppose concepts from psychology. Thus, psychology can indeed be categorized as part of the social sciences, although this does not necessarily warrant categorizing all of its subfields as social sciences. Lastly, it is likely that the existing divide in the theoretical framework and methodology within the field will persist, which is something to keep in mind for further works on this matter.