DOI resolved by resea

Inclusion of Other in the Self Scale and the structure of interpersonal closeness.

In 2 studies, the Inclusion of Other in the Self (IOS) Scale, a single-item, pictorial measure of closeness, demonstrated alternate-form and test-retest reliability; convergent validity wit…

Arthur Aron, Elaine N. Aron, Danny Smollan
https://resea.org/10.1037/0022-3514.63.4.596

Abstract

In 2 studies, the Inclusion of Other in the Self (IOS) Scale, a single-item, pictorial measure of closeness, demonstrated alternate-form and test-retest reliability; convergent validity with the Relationship Closeness Inventory (Berscheid, Snyder, & Omoto, 1989), the Sternberg (1988) Intimacy Scale, and other measures; discriminant validity; minimal social desirability correlations; and predictive validity for whether romantic relationships were intact 3 months later