The overall aim of the present study was to further the understanding and measurement of eudaimonic well-being (EWB) or "functioning well" across different demographic and cultural groups by implementing modern psychometric techniques. This was done by exploring in three manuscripts the cross-cultural psychometric properties of measurement instruments that operationalise three prominent theories associated with EWB. The first manuscript applied Rasch modelling to explore the psychometric properties of the Meaning in Life Questionnaire (MLQ) among adults from South Africa, Australia, and New Zealand (N = 601). The findings revealed that using less response categories and removal of the reversed-phrased item in the scale may improve the scale's functioning. The Presence subscale exhibited differential item functioning on several items for the country variable. It was found that the Presence subscale was insensitive at high levels of presence of meaning while the majority of the respondents fell in that range. Reasons for, as well as the far-reaching implications of this finding, were contemplated. The second manuscript explored the suitability of applying a bifactor model to English, Afrikaans, and Setswana versions of the Mental Health Continuum Short Form (MHC-SF) among South African university students (N = 1060). A bifactor model consistently displayed superior fit, and it was shown that the scale total score can be used as a reliable indication of overall positive mental health, but that it is not appropriate to interpret subscale scores. The findings highlighted the lack of focus on contribution towards a greater good beyond the self in the present scale, indicating the necessity of more attention to this important aspect of functioning well in future research. The scale exhibited configural, partial metric, and partial scalar invariance across the three samples and the average scale total score did not differ practically significantly across the groups. The third manuscript explored the factorial validity of English, Afrikaans, and Setswana versions of the Basic Psychological Needs Scale (BPNS) among South African university students (N = 1056). After incorporating a negative-worded method effect and removing several problematic items, the fit of the intended three-factor model was good for the Afrikaans version, marginal for the English version, and poor for the Setswana version of the scale. The resulting factors' reliabilities were low. Configural, metric, and partial scalar invariance were established between the English and Afrikaans versions. These findings not only highlighted problems with the particular scale, but also raised questions about the universality assumption of the basic psychological needs theory. The study also emphasised the linguistic and cultural complexities involved in working within diverse and multicultural communities. Overall, significant conclusions regarding the theory and measurement of EWB crystallised. The study showed that caution should be applied when transferring theories and their operationalisations from one context or culture to another and that measurement within diverse multicultural communities poses certain complexities and challenges. In addition, it was found that the nuances of positive traits and experiences at high levels may not be well understood. The findings suggested that a strong general factor of well-being exists, while, at the same time, unique subdimensions can be distinguished and interpreted, given that they are measured comprehensively. General pointers that will enhance the construction of measurement instruments of EWB in diverse contexts flowed from the study. For example, the crucial importance of proper attention to the substantive phase of scale development where the construct is clearly conceptualised along the full spectrum of the latent trait continuum was highlighted, as well as the importance of using reversed-phrased items in an appropriate manner. This study furthered the science of EWB on theoretical and measurement levels, which can, in turn, be applied to develop culture-sensitive interventions that truly enhance the lives of people

PhD (Psychology), North-West University, Potchefstroom Campus, 2016

Doctoral