Wisdom and intelligence are complex distinct constructs which share some characteristics. Measures of wisdom should be distinguished from the construct of intelligence, because, although intelligence helps us engage in our environment, wisdom assists us in dealing with life’s existential challenges. Yet, wisdom a master virtue, often lacks valid and reliable measures. This thesis investigated how wisdom and intelligence are influenced by age and gender, in two quantitative studies. Study One examined whether the structural validity of the popular 40-item five factor Self-Assessed Wisdom Scale (SAWS) would replicate in our sample. We also tested multigroup invariance, and SAWS Openness dimension as a wisdom precursor proposed by other models. Data from 709 respondents, aged 15–92 were randomly split into two. Confirmatory factor analysis (CFA) on Sample 1 showed that the SAWS factor structure did not fit the data. Exploratory factor analysis (EFA) on Sample 2 offered an alternative model, a 12-item four factor solution (SAWS-12), without a Humour facet. SAWS-12 demonstrated a good fit and measurement invariance (MI) across age groups and gender. In respect to findings relative to age, all adults were wiser than adolescents and young adults differed in wisdom from midlife adults. These two groups were similar to older persons. Despite women being wiser than men, the effect size was small. In Study Two, CFA cross-validated the SAWS-12 structure with 457 participants aged 16–87 and compared the measure with the Three-Dimensional Wisdom Scale-12 (3D-WS-12). SAWS-12 displayed good discriminant validity, but not 3D-WS-12, since 3D-WS-12 shared similar r = .34 with both SAWS-12 and crystallised intelligence (Gc). Again, women scored higher on SAWS-12, but there were no gender differences on 3D-WS-12. On both measures, wisdom–age trajectory was curvilinear with peak at midlife, corroborating current literature. Older adults’ mean wisdom scores did not differ from younger or midlife groups. Highest wisdom scorers were older on both wisdom measures, but better educated only on 3D-WS-12. On measures of Gc and fluid intelligence (Gf) there were no gender differences. While Gc linearly inclined with ageing, Gf’s inverse U–curve ageing trajectory was almost flat. Although intelligence failed to mediate the relationship between age and SAWS-12, Gc mediated 3D-WS-12 with age. Age and gender did not moderate the relationship between intelligence and wisdom. This thesis established new findings. We confirmed SAWS Openness facet is a basic component of wisdom, whereas the Humour factor is not. We demonstrated ceiling and cohort effects, opposing and challenging declining Gf with age reported in contemporary literature. SAWS-12 as a new measure of wisdom demonstrated excellent psychometrics superior to the 3D-WS-12, replicated in a new population across time, displayed convergent and discriminant validity, and MI across age groups and gender. This suggests SAWS-12 is a short, direct, reliable measure of wisdom, which offers distinct advantages to research where increments of time are the focus of the study, such as longitudinal studies, and for vulnerable population groups with short attentional spans
