From Intellectual Investment Trait Theory to Dynamic Intellectual Investment Trait and State Theory: Theory extension, methodological advancement, and empirical illustration

This paper introduces Dynamic Intellectual Investment Trait and State Theory, an extension of Intellectual Investment Trait Theory. Our theory extension (a) centers on dynamic within-person effects of cognitive performance states on intellectual investment personality states and vice versa (i.e., reciprocal effects), (b) integrates within-person dynamics and developmental trajectories in cognitive abilities and intellectual investment traits, and (c) is embedded in a continuous-time modeling framework. Aligning personality theories with statistical models, we discuss the most appropriate model for testing Dynamic Intellectual Investment Trait and State Theory: a continuous-time model that combines dynamics and trends. We apply the Continuous-time Latent Curve Model with Structured Residuals (CT-LCM-SR) in an empirical illustration involving 204 German adults who were assessed roughly 100 times on cognitive abilities (working memory) and intellectual investment personality (interest).