“…The results of quantitative content validity also showed acceptable content validity of the MPFI-60 items. Confirmatory factor analysis, consistent with previous psychometric work (Landi, Pakenham, Giovannetti, et al, 2021 ; Lin et al, 2020 ; Rolffs et al, 2018 ; Seidler et al, 2020 ; Thomas et al, 2021 ) and the Hexaflex model (Hayes et al, 1999 , 2012 ), yielded a second-order factor structure consisting of six first-order factors for psychological flexibility (i.e., acceptance, present moment awareness, self as context, defusion, values, and committed action) and six first-order factors for psychological inflexibility (i.e., experiential avoidance, lack of contact with present moment, self as content, fusion, lack of contact with values, and inaction). The factor loading values of all indicators were above 0.5 (ranging from 0.51 to 0.89), so they all remained on the scale.…”