What are psychological constructs? On the nature and statistical modelling of emotions, intelligence, personality traits and mental disorders

Many scholars have raised two related questions: what are psychological constructs (PCs) such as cognitions, emotions, attitudes, personality characteristics and intelligence? And how are they best modelled statistically? This commentary provides (1) an overview of common theories and statistical models, (2) connects these two domains and (3) discusses how the recently proposed framework pragmatic nihilism fits in. For this overview, I use an inclusive definition of the term ‘psychological construct’ that also encompasses mental disorders. This is consistent with recent efforts such as the research domain criteria (RDoC) that aim to refine such constructs, and is relevant given many recent discussions on the nature of psychopathology