An item response theory analysis of self-report measures of adult attachment.

TLDR

Self‑report attachment measures are often scored by averaging or summing items, which can lead to erroneous inferences about attachment continuity and stability. The study aimed to assess scaling problems in four common self‑report attachment inventories using item response theory. Data from 1,085 participants were analyzed with Samejima’s graded response model. The analysis revealed that existing scales can be improved and that IRT can be used to develop new attachment scales with better psychometric properties.

Abstract

Self-report measures of adult attachment are typically scored in ways (e.g., averaging or summing items) that can lead to erroneous inferences about important theoretical issues, such as the degree of continuity in attachment security and the differential stability of insecure attachment patterns. To determine whether existing attachment scales suffer from scaling problems, the authors conducted an item response theory (IRT) analysis of 4 commonly used self-report inventories: Experiences in Close Relationships scales (K. A. Brennan, C. L. Clark, & P. R. Shaver, 1998), Adult Attachment Scales (N. L. Collins & S. J. Read, 1990), Relationship Styles Questionnaire (D. W. Griffin & K. Bartholomew, 1994) and J. Simpson's (1990) attachment scales. Data from 1,085 individuals were analyzed using F. Samejima's (1969) graded response model. The authors' findings indicate that commonly used attachment scales can be improved in a number of important ways. Accordingly, the authors show how IRT techniques can be used to develop new attachment scales with desirable psychometric properties.