Are the dimensions of meaning in life distinct? A bifactor model of comprehension, purpose, and mattering with four samples

In recent years, the tripartite conceptualization of meaning in life (MIL) including (a) coherence/comprehension, (b) purpose, and (c) significance/mattering has received growing scholarly consensus and some support from factor analytic findings. However, a considerable body of studies has shown that the three MIL dimensions are highly correlated, suggesting the potential for MIL's unidimensionality. Therefore, the purpose of this study was to investigate whether a bifactor model, compared to other plausible models, best explained the relations among three MIL dimensions, namely, comprehension, purpose, and mattering. Using four different samples (4,041_T1 and 2,717_T2 midlife adults, 610 adults, 956 college students, and 346 patients with chronic illnesses), results indicated that the bifactor model best fit the data, compared to the unidimensional model and the correlated three-factor model. The bifactor model provided evidence for an overarching MIL factor. Ancillary bifactor indices favored the unidimensionality of MIL. The findings provide conceptual, measurement, and practical implications for MIL researchers and practitioners. (PsycInfo Database Record (c) 2025 APA, all rights reserved).