Development and validation of the Companion Animals Self-Expansion Scale

Abstract Although many people experience a close and complex relationship with their companion animals, our understanding and measurement of this relationship has lagged far behind that of human-human relationships. Important advances in human-human relationship concepts and measurement have yet to be applied in the context of human-companion animal relationships, including the critically relevant concept of self-expansion (i.e. the process through which positive content is added to the self). The aim of this research was to develop and validate a new full and short-form measure of self-expansion within the human-companion animal relationship, the Companion Animals Self-Expansion Scale (CASES). The sample included in the exploratory factor analysis (EFA) phase consisted of 366 adult English-speaking companion animal owners, while the sample included in the confirmatory factor analysis (CFA) phase consisted of 368 adult English-speaking companion animal owners. All participants completed demographic questions and the CASES. Analyses revealed the full version of the CASES to be 15 items, six of which were retained for the short form of the scale based on their consistently high-factor loadings and theoretically relevant content. The CASES, as well as its short form, the CASES-SF, are both reliable and valid in measuring self-expansion within the human-companion animal relationship.