Background. Psychological flexibility and psychological inflexibility comprise two sets of complementary psychological processes that together form the Hexaflex model of Acceptance and Commitment Therapy (Hayes, Luoma, Bond, Masuda, & Lillis, 2006). The Multidimensional Psychological Flexibility Inventory (MPFI; Rolffs, Rogge, & Wilson, 2018) is a comprehensive and psychometrically validated measure of both psychological flexibility and inflexibility.
Hypothesis/Research question. The current studies examined whether psychological flexibility and inflexibility, as assessed with the MPFI, predict eudaimonic and hedonic wellbeing.
Sample Characteristics and Sample Size. 315 and 345 undergraduate students completed Study 1 and Study 2, respectively.
Design. Participants completed the MPFI along with three measures of eudaimonic wellbeing (in Study 1) or three measures of hedonic wellbeing (in Study 2).
Results. In both studies, psychological flexibility and inflexibility scores significantly and independently predicted wellbeing. Moreover, in Study 2, the prediction of hedonic wellbeing by MPFI scores persisted when including two established predictors of wellbeing (meaning in life and psychological need satisfaction/frustration).
Scientific Contribution. These studies are the first to systematically assess the relationship between individual differences in psychological flexibility and inflexibility, on the one hand, and wellbeing, on the other. The domain of wellbeing studies may benefit from ongoing testing of the role played by psychological flexibility and inflexibility in peoples’ wellbeing.