Using signature strengths for a good day: Need-based pathways to daily hedonic, eudaimonic, and social well-being.

Using one's signature strengths is a robust predictor of well-being, yet the psychological mechanisms underlying this association remain insufficiently understood. Drawing on self-determination theory's dual-process model, the present study examined whether basic psychological need satisfaction and need frustration serve as parallel mediators of the relationship between daily signature strengths use (SSU) and three dimensions of well-being, namely hedonic, eudaimonic, and social well-being. A sample of 224 Chinese college students completed daily assessments for 14 consecutive days (N = 2491 daily observations). Multilevel structural equation modeling with the 1-1-1 mediation framework revealed a striking level-dependent asymmetry: At the within-person level, need satisfaction, but not need frustration, mediated the daily SSU-well-being relationship across all three outcomes, whereas at the between-person level, need satisfaction mediated the associations with all three outcomes and need frustration mediated those with hedonic and eudaimonic well-being only; the need satisfaction pathway was consistently stronger. Exploratory dimension-specific analyses suggested a tentative pattern involving competence frustration at the between-person level, although this finding was based on a single-item measure. These findings support the proposed role of need satisfaction as an important mechanism linking daily strengths use to multidimensional well-being.