OBJECTIVE: The current study aimed to determine the changes in psychological function that come with age. The basis to assess psychological function was a hierarchical model of temperament, personality and character, previously developed by the authors.METHODS: 734 general population subjects completed the TEMPS-A, the TCI and the NEO-PI-3. Data were analysed with ANCOVA models.RESULTS: The top superfactors showed no age change, however, age-related changes were identified in the higher and lower modules. There was a pattern of differences between the two genders in all levels of the model.CONCLUSIONS: While there is stability with the two top factors of personality, there are age-related changes in lower-level modules probably indicating maturation, adaptation or changes in orientation through the adult life span. Gender differences in all levels including the two top superfactors, higher and lower modules reflect and explain differences in multiple aspects of internal experience, interaction and behaviour in the two genders. The results are clinically essential for incorporating age and gender-related differences of experience and behaviour in understanding temperamental implications in affective disorders also impacting their clinical course and management. Key Points Based on the complex hierarchical temperament model four stages of maturation of human psychological function can be postulated. There is a very specific trait core of human mental function, which differs between genders and seems to be responsible for the longitudinal stability of the person's internal experience with the passing of the years. The findings are clinically essential for incorporating age and gender-related differences of experience and behaviour in understanding temperamental implications in affective disorders also impacting their clinical course and management.