Tracing the Trajectory of Charles Manson's Interpersonal Dynamics: A Longitudinal Moment-to-Moment Analysis Using Continuous Assessment of Interpersonal Dynamics (CAID).

Charles Manson, notorious for his involvement in the gruesome Tate-LaBianca murders of 1969, remains a polarizing figure. His case has divided not only the public but also clinicians and researchers, resulting in a wide array of diagnoses from personality disorders to schizophrenia. To shed light on this longstanding debate, this study employs a novel approach to systematically assess moment-to-moment dyadic interpersonal exchanges between Manson and several interviewers over a 21-year span. Utilizing Continuous Assessment of Interpersonal Dynamics (CAID), we analyzed seven video-recorded interviews of Manson from 1972 to 1993. Unified Structural Equation Modeling revealed a consistent pattern of dominant and cold interpersonal behavior. Manson demonstrated high agency (dominance) and low communion (warmth) across all interactions but also the capacity for strategic interpersonal behaviors and goal-directed communication, contrasting with disorganized patterns typically associated with schizophrenia. Simulation Modeling Analysis revealed a progressive intensification and rigidity of dominant-cold interpersonal patterns over time. Our findings suggest that Manson's interpersonal style aligns more with severe personality pathology, particularly features of malignant narcissism, rather than a primary psychotic disorder. The study offers a new methodology to investigate complex cases of severe psychopathology and highlights the potential of assessing momentary interpersonal processes in forensic and clinical settings.