Interaction is not interaction: An interview with Fred Hasselman

I had the opportunity to interview Fred Hasselman, the main architect of casnet: An R toolbox for studying Complex Adaptive Systems and NETworks. We spoke of how compatible the complex systems perspective is with some methods widely used in social sciences.

A few notes:

  • Multilevel models (and what you put in those) come in many varietiesand some are useful
  • Interaction is not interaction
    • Interaction (1): Two variables are intertwined – or “coupled” – in such a way, that they cannot be separated without severing the phenomena arising from their interplay.
    • Interaction (2): A multiplicative, instead of additive, relationship in a linear regression model, where you can partial out variance and get nice beta weights for each variable to determine their individual impacts.
    • The two meanings presented above are logically inconsistent: See #36 in Scott Lilienfield’s “Fifty psychological and psychiatric terms to avoid
  • Interdependence means you can’t use the regular statistics which social scientists know and love.
    • … because you lose additivity.
  • “Don’t infer causality, observe it.”
    • When the system you’re looking at is an individual instead of e.g. the society, you’re in the quite happy position, that lab studies are possible (if you’re smart about them).
  • An excellent paper from Merljin Olthof: Complexity in psychological self-ratings: implications for research and practice
  • Additional resources:
    • A symposium we held on complexity in behavioural science, evidence and policy.
    • A workshop by Fred Hasselman (scroll to the end for an extensive reading list).
    • University of Helsinki course by Matti: CARMA – Critical Appraisal of Research Methods and Analysis.

Because every post needs an image, here’s Julia Rohrer‘s (2017) Theory of Regulation of Empty Theories (TROETE)