Objectives: The aim of this study was to test Lyubomirsky et al’s (2005) theory of “sustainable happiness” by using volitional intentional activities to predict increases in subjective well-being (SWB), and additionally, considering whether certain personalities, motivation or goal behaviour contributed to changes in happiness.
Method: 78 participants were tested over 9 weeks (6 weeks first semester, 3 weeks second semester). Participants took part in both the experimental condition where they were instructed to set goals, and the placebo group where were allocated set activities to complete each week. Personality was measured using the NEO Five Factor Inventory (NEO-FFI; Costa & McCrae, 1992). SWB levels were measured each week using the Satisfaction with Life Scales (SWLS; Diener et al. 1985), Subjective Happiness Scales (SHS; Lyubomirsky & Lepper, 1999) and the Positive Affect Negative Affect Scales (PANAS; Watson et al, 1988). The analysis of data included correlations, analysis of variances and regressions.
Results: Overall SWB increased and negative affect decreased during the experimental conditions. There were no effects for positive affect. Personality had modest influences on SWB, with conscientiousness showing to influence SWB indirectly by predicting the number of goals achieved. SWB increases did not persist throughout the washout period.
Conclusions: Lyubomirsky et al’s (2005) theory of sustainable happiness was partially supported as the results showed increases in SWB. Personality and other individual behaviours had small influences on intentional activities and SWB. Future research is advised to modify the model by improving the individual behaviour measurements and perhaps testing the model on participants who have SWB levels below average. Furthermore there is the suggestion that individuals should gain a better understanding of themselves to ensure their personalities are concordant with their goals, in order to produce a greater effect of increased SWB.||en