Abstract
Psychological flexibility and inflexibility are core processes in the Acceptance and Commitment Therapy (ACT) model and are consistently associated with well-being and emotional distress. However, the validity of widely used measures, particularly the Acceptance and Action Questionnaire – II (AAQ-II), has been questioned due to potential overlap with indicators of distress and neuroticism. This study examined the psychometric properties of the Acceptance and Action Questionnaire – III (AAQ-III) and the PsyFlex in a general population sample from Colombia (
N
= 785) using network psychometrics. We estimated the dimensionality of each scale via Exploratory Graph Analysis (EGA) and evaluated replicability via bootstrap EGA (bootEGA). Discriminant validity was examined using a joint EGA that included the AAQ-III, PsyFlex, and measures of emotional distress (DASS-21) and neuroticism (BFI-2-Neuroticism). Convergent validity was assessed through correlations with the Multidimensional Psychological Flexibility Inventory – Short Form. EGA identified unidimensional structures for both instruments, and bootEGA confirmed perfect structural consistency and item stability. The joint EGA yielded five distinct communities, with the AAQ-III and PsyFlex forming separate communities from emotional symptoms and neuroticism, providing structural evidence consistent with the discriminant validity of both measures. Both instruments showed the expected patterns of correlations with flexibility and inflexibility processes. These findings provide initial validation evidence that the Spanish versions of the AAQ-III and PsyFlex are psychometrically sound measures of psychological inflexibility and flexibility.