Date of Award


Degree Name

Master of Arts



First Advisor

Drake, Chad


The model of psychological flexibility and inflexibility presented within an Acceptance and Commitment Therapy (ACT) framework is one that is multifaceted and complex. Until recent years, however, measurement of the construct of psychological flexibility has largely been conducted in a unidimensional manner across research and clinical contexts. The emergence of the Multidimensional Psychological Flexibility Inventory (MPFI; Rolffs et al., 2016) has remedied this situation by providing the first assessment of its kind to simultaneously capture each dimension of the full psychological flexibility model in a theoretically consistent manner. The current study intends to provide independent validation of the MPFI’s psychometric properties and to further solidify the measure’s utility in more comprehensively measuring ACT constructs for research and clinical contexts. The study will examine the MPFI’s convergence with related measures, its predictive validity with pertinent outcomes, and its utility in relation to the current standard of psychological flexibility measurement.




This thesis is only available for download to the SIUC community. Current SIUC affiliates may also access this paper off campus by searching Dissertations & Theses @ Southern Illinois University Carbondale from ProQuest. Others should contact the interlibrary loan department of your local library or contact ProQuest's Dissertation Express service.