What does the Acceptance and Action Questionnaire (AAQ-II) really measure?

Area of Science:

• Psychology
• Clinical Psychology
• Psychometrics

Background:

• The Acceptance and Action Questionnaire-II (AAQ-II) is widely used to measure psychological flexibility.
• Its validity in distinguishing psychological flexibility from psychological well-being outcomes is under examination.
• The measure's centrality in validating the ACT model necessitates rigorous psychometric evaluation.

Purpose of the Study:

• To assess the AAQ-II's ability to discriminate between experiential avoidance/psychological flexibility and psychological well-being.
• To identify underlying factors within an item pool including AAQ-II and custom-designed items.
• To determine the factor loadings of AAQ-II items.

Main Methods:

• Exploratory factor analysis was employed.
• An item pool comprised AAQ-II items and newly developed items measuring distress and acceptance/non-acceptance.
• Factor loadings were analyzed to understand item relationships.

Main Results:

• AAQ-II items demonstrated stronger associations with distress than with acceptance/non-acceptance.
• Minimal loadings were observed for items related to functional outcomes.
• The factor structure indicated a potential conflation of constructs.

Conclusions:

• The AAQ-II's discriminant validity may be compromised, as it appears more closely aligned with distress than acceptance.
• Findings raise questions about the AAQ-II's utility in its current form for measuring psychological flexibility.
• Implications for the use of the AAQ-II in clinical practice and research, particularly within the ACT framework, warrant careful consideration.