Foundations of classification and category-based induction in the social and behavioral sciences (2015-2018)

In 2015, the Academy of Finland decided to fund my three-year project on the philosophy of classification. In this project, my focus is especially on the social and behavioral sciences. A central tenet of my research was that the philosophical discussions associating scientific concepts (too) tightly with philosophical theories of natural kinds had resulted in an unfortunate disconnect between many philosophical views on scientific concept formation and category-based inference on the one hand, and actual scientific practices and methodological reflection, on the other.


What kinds of things are there in the world? How should scientific concepts and classifications be formulated, so that they reliably support prediction, explanation, and manipulation of phenomena? In philosophy, ontological and epistemological questions pertaining to categories, classifications, and category-based inductive inference have mainly been addressed in the literature on natural kinds. Since the 1990s the natural kinds approach to scientific concepts has been applied also to the social and behavioral sciences. However, social-science classifications have properties that make it questionable whether they can be treated as natural kinds:

  1. The grounds of inductive success in the social sciences differ from the natural sciences: Phenomena are local, mutable, not directly sustained by laws of nature, and often depend on collectively shared beliefs.
  2. As illustrated by the case examples studied in the project (addiction research; psychology of decision-making and its policy- applications), there are intricate dependencies between classifications, policy, and everyday thought. Classifications are often normatively and politically loaded, and the knowledge encapsulated in them often feeds back into our self-understanding and behavior, hence making the studied social categories unstable.
  3. There are few overarching theories in the social and behavioral sciences. Instead, research is organized around shared targets and concepts, which act as nodes bringing together various theoretical perspectives.

By building on recent philosophy-of-science discussions on mechanisms, interfield integration, and boundary concepts, my project improves on the natural kinds approach in three ways:

  1. I connect Richard Boyd’s mechanistic theory of kinds with recent accounts of explanation and causality to develop a mechanistic extrapolation theory of category-based induction.
  2. My new mechanisms-based theory of classification provides a rigorous account of social construction and performativity of classifications.
  3. I argue that not all scientific concepts are causally grounded. Understanding theoretical integration in interdisciplinary research requires paying attention to framework concepts (e.g. RATIONALITY, AGGRESSION), which mediate between research fields. Together these contributions result in a novel, scientifically applicable account of the foundations and the inferential functioning of social-science concepts and classifications.

Relevant publications

Reijula, Samuli (forthcoming 2021) Social categories in the making: construction or recruitment? , Synthese. [pdf, open access]

Reijula, Samuli (2021) Hacking, Ian (1936-), Routledge Encyclopedia of Philosophy. [link] [pdf]

Pöyhönen, Samuli (2016). Memory as a cognitive kind. Brains, remembering dyads and exograms, in C. Kendig (ed.), Natural Kinds and Classification in Scientific Practice. London: Pickering & Chatto, 145–156. [link] [pdf]

Ylikoski, Petri & Samuli Pöyhönen (2015). Addiction-as-kind hypothesis. International Journal of Alcohol and Drug Research, 4(1): 21–25. [link] [pdf]

Pöyhönen Samuli (2014). Natural kinds and concept eliminativism, in V. Karakostas and D. Dieks (eds.), EPSA11 Perspectives and Foundational Problems in Philosophy of Science, The European Philosophy of Science Association Proceedings 2, 167-179. [pdf]

Pöyhönen, Samuli. (2014). Intentional concepts in cognitive neuroscience, Philosophical Explorations, 17: 93–109 [link] [pdf] Kuorikoski, Jaakko & Samuli Pöyhönen (2012). Looping kinds and social mechanisms, Sociological Theory, 30:3, 187–205. [link] [pdf]

Rusanen, Anna-Mari & Samuli Pöyhönen (2012). Concepts in change, Science & Education, 22, 6, 1389-1403. [link] [pdf]

Pöyhönen, Samuli. (2012) Carving the mind by its joints – Natural kinds and social construction in psychiatry, in Milkowski, Martin, and Konrad Talmont-Kaminsky (eds.) Regarding Mind, Naturally. Cambridge Scholars Publishing, [pdf]