Relationship satisfaction: Establishing measurement and structural invariance across men with gay and straight identity

The Relationship Assessment Scale (RAS; Hendrick, 1988) is a widely employed, seven-item measure of relationship satisfaction. However, research on its measurement invariance across people differing in their sexual orientation identity has yet to be conducted. Consequently, it is still an open question whether the RAS can be used for comparative research across gay and straight people. This study starts filling this gap in examining RAS' measurement invariance across gay and straight men. To this end, we drew on a sample of 644 German men (half gay/straight), who responded to the German-version RAS (Hassebrauck, 1991), which has been extensively validated and found to be equivalent to its English counterpart. A stepwise multigroup confirmatory factor analysis was used to examine configural, metric, and scalar invariance as well as the structural invariance of latent factor variances and means across groups. Configural, metric, and partial scalar measurement invariance (by freeing one item intercept) could be established, indicating that the RAS enables comparative research targeting variances and means. Further, structural invariance testing revealed non-invariant variances but invariant latent means across groups, indicating that gay and straight men's reported relationship satisfaction is equally high albeit differently distributed.