Gratitude questionnaire: psychometric properties in Portuguese adult samples and evidence of validity

Gratitude has been increasingly studied as a key psychological strength associated with subjective well-being, positive interpersonal relationships, and mental health. The assessment of gratitude through validated instruments is essential for both research and clinical practice. Although the Gratitude Questionnaire 6 items (GQ-6) is widely used in various cultural contexts, there is a need to evaluate its psychometric properties and cultural relevance in Portuguese-speaking populations, particularly among adults.

The present study aimed to examine the psychometric properties and validity evidence of the Portuguese version of the Gratitude Questionnaire, with a focus on its internal structure, score reliability, and evidence based on relations to other variables.

A final sample of 810 Portuguese adults (Mage = 43.79; SD = 23.69) completed the Portuguese version of the GQ-6. Exploratory factor analysis and confirmatory factor analysis were conducted to evaluate the instrument's internal structure. A subsample of 362 adults completed the revised 5-item version (GQ-5), along with measures of life satisfaction and loneliness, to assess evidence based on relations to other variables.

Findings supported a one-factor structure, with the 5-item version showing a better model fit than the original 6-item scale. The GQ-5 demonstrated significant positive correlations with life satisfaction and negative correlations with loneliness, supporting this source of validity evidence. The instrument also exhibited adequate internal consistency.

The Portuguese version of the GQ-5 is a psychometrically sound and culturally appropriate measure for assessing gratitude in adult populations.