ABSTRACT
Understanding the co-development of moral personality and beliefs about control over well-being is essential for clarifying how individuals sustain mental health. However, the theoretical linkage between moral personality and beliefs about the causation of well-being remains underexplored. Addressing this gap, the present study examined the reciprocal dynamics between honesty–humility and internal well-being locus of control (Internal WB-LOC). Drawing on four–wave longitudinal data from 1349 Chinese participants, we employed random intercept cross-lagged panel models to investigate these associations. Results demonstrated stable between–person effects, indicating that individuals with high levels of honesty–humility tend to exhibit greater Internal WB-LOC across time. Results also showed concurrent positive associations within individuals and cross-lagged effects, indicating that increases in levels of honesty–humility temporally precede increases in Internal WB-LOC, and vice versa. These findings integrate personality research with belief systems about well-being, suggesting a dynamic interplay in which internalised moral orientation and perceived agency over well-being are mutually reinforcing.