The Object Attachment Security Measure: Assessing Convergent and Divergent Validity, Confirmatory Factor Analysis, and Measurement Invariance Across Age, Gender, and Hoarding Severity.

Past research shows strong links between object attachment and hoarding but has relied on poorly validated measures of object attachment. The Object Attachment Security Measure (OASM; David & Norberg, 2022b) was developed to address this limitation. This study evaluates the construct validity and measurement invariance of the OASM across age groups, genders, and hoarding severity. Participants were 777 individuals recruited via Prolific. Confirmatory factor analysis confirmed the correlated two-factor structure with two subscales: secure object attachment (SOA) and insecure object attachment (IOA). Measurement invariance testing showed strict invariance across age, gender, and hoarding severity. SOA and IOA had moderate to strong correlations with hoarding, and weaker associations with other psychopathology. IOA showed stronger correlations with hoarding than SOA, and the relationship between SOA and hoarding was no longer significant after accounting for IOA. These findings support the construct validity of OASM and reaffirm the central role of insecure object attachment in hoarding.