Psychology’s Theory Crisis, and why formal modelling cannot solve it

In light of psychology’s ‘theory crisis’, multiple authors have argued that adopting formalization and/or formal modelling would constitute a useful or even necessary step towards stronger psychological theory. In this article, I instead argue that formal modelling cannot solve the core problem the psychological ‘theory crisis’ refers to, which are the currently high degrees of contrastive and holistic underdetermination of our theories by our data. I do so by first introducing underdetermination as an explanatory framework for determining the evidential import of research findings for theories, and showing how both broader theoretical considerations and informal assumptions are key to this process. Then, I derive the aforementioned core problem from the current ‘theory crisis’ literature and tentatively explore its possible solutions. Lastly, I show that formal modelling is neither a necessary nor sufficient solution for either contrastive or holistic underdetermination, and that its uncritical adoption might instead worsen the crisis.