Structure, stability, and mean-level change in adolescent HEXACO personality traits using the HEXACO-SPI

We used a new English version of the HEXACO-Simplified Personality Inventory (HEXACO-SPI) to examine (1) its dimensional structure and (2) the developmental stability and mean-level changes in its personality traits among adolescents. Our results showed that the HEXACO-SPI factor scales were consistent with the a priori hypothesized six-factor structure of HEXACO personality and that the HEXACO-SPI domain scales demonstrated sufficiently high levels of internal reliability, differentiation, and invariance across time. Stability was shown for all domain scales, but especially when considering 1-year estimates (versus 3 or 4-year estimates). Mean-level decreases were observed in Honesty-Humility, Extraversion, Agreeableness, and Conscientiousness, with stability in Emotionality and Openness to Experience. Our findings inform research on HEXACO personality in adolescence, including stability and change.