Motivation Science, Vol 12(1), Mar 2026, 1-15; doi:10.1037/mot0000372
This article traces the development of Julius Kuhl’s research program on motivation and personality over the past 50 years. Starting in the 1970s with a then innovative computational approach to achievement motivation, Kuhl shifted the focus from mental contents (expectancy, value) to the functional analysis of dynamic and content-free processes underlying motivation and personality, which led to the development of action control theory. His action-theoretical perspective and empirical work culminate in personality systems interactions (PSI) theory, which integrates insights from personality, motivation, emotion, cognitive, social, and clinical psychology, as well as neuroscience. PSI theory explains many aspects of human behavior and experience (e.g., action control and self-growth) in terms of the temporary and/or chronic activation of four cognitive macro systems (i.e., intention memory, extension memory, intuitive behavior control, object recognition), which is subject to (even subtle) changes in positive and negative affect. Therefore, affective shifting and the ability to self-regulate affect (action vs. state orientation) are central resources for personality functioning and an integral part of PSI theory. Insights from PSI theory have been widely applied in clinical, educational, counseling, and organizational psychology. (PsycInfo Database Record (c) 2026 APA, all rights reserved)