Demarcating disciplines
It is easy to distinguish disciplines if they are very different, as is the case for political science and physics. But if you think about different fields within a narrow domain, such as brain and cognitive sciences, it becomes much harder to set the boundaries. Is clinical psychology distinct from cognitive psychology? How does cognitive psychology related to behavioural science? Is cognitive neuroscience a field in itself?
The demarcation of disciplines is constantly renegotiated by scientists, as they label their work as being of a new kind or join forces with others who have successfully raised a banner to describe their research programme. Indeed, attempts to define what a discipline often yield rather political descriptions. For example, Turner (2000) writes:
"Disciplines are kinds of collectivities that include a large proportion of persons holding degrees with the same differentiating specialization name, which are organized in part into degree-granting units that in part give degree-granting positions and powers to persons holding these degrees; persons holding degrees of this particular specialized kind are employed in positions that give degree-granting powers to them, such that there is an actual exchange of students between different degree-granting institutions offering degrees in what is understood to be the same specialization."
In this view, an interdisciplinary student could in principle identify distinct disciplines by checking whether they have their own degree and are "understood as their own specialisation". This formulation, however, still leaves wiggle room to those seeking to separate or merge particular specialisations.
To further complicate matters, disciplines can move closer to each other via both methodological and conceptual developments, which are two dimensions of science that are in perpetual motion. For example, the introduction of functional magnetic resonance imaging brought neuroscience closer to psychology, while theoretical work on decision-making brought together microeconomics and cognitive psychology. Leydesdorff & Schank (2008) have attempted to visualize relative vicinities of disciplines (or research fields) via journal maps.
Heuristics for identifying disciplines
If defining disciplines cannot be done analytically, perhaps there are some heuristics that can help. If in doubt, ask yourself the following questions:
- Finish the sentence "the aim of this field is to understand how..." for both potentially different disciplines. Do they lead to clearly different answers? Then their problem space is different, which is a hallmark of a discipline.
- Which experimental approaches are common in the potentially different disciplines? Disciplines are often organised around a particular set of methods or paradigms and these limit their explanatory scope. So if you find that the potentially different disciplines have different methodological approaches, that strengthens the case for them being indeed distinct.
- Do the potentially different disciplines have different interpretative frameworks? For example, systems neuroscience and 4E cognition can interpret experimental results in different ways. This makes them eligible candidates for distinct disciplines.
None of the answers to these questions are definitive. Yet thinking about them (and discussing them) can help clarify whether there's enough distance between any two approaches to call them disciplines and to warrant interdisciplinary integration.
References
Leydesdorff, L., & Schank, T. (2008). Dynamic animations of journal maps: Indicators of structural changes and interdisciplinary developments. Journal of the American Society for Information Science and Technology, 59(11), 1810-1818.
Turner, S. (2000). What are disciplines? And how is interdisciplinarity different? Practising interdisciplinarity, 46-65.