Components of Connection: Development and Validation of the Romantic Chemistry (RoCh) Scale in Single and Partnered Community Samples

Romantic chemistry is a widely referenced yet poorly assessed construct in psychology research. We aimed to develop and psychometrically validate the Romantic Chemistry (RoCh) scale, a measure designed to assess the perceived reciprocal connection between current or potential romantic partners—a construct that may have implications for relationship maintenance and overall well-being. Across four studies with single and partnered individuals and romantic couples, we used a hybrid bottom-up and theory-guided approach grounded in the Interpersonal Chemistry Model to generate, refine, and validate scale items. In Studies 1a (n = 200) and 1b (n = 201), lay definitions and theory-driven content informed an initial item pool. Study 2 (n = 1,094) applied exploratory factor analysis and item response theory to refine the scale and examine its dimensional structure. Study 3 (n = 1,113) confirmed a multidimensional structure comprising five components—compatibility, comfortability, unique connection, positive interaction, and sexual attraction—and demonstrated strong internal consistency, convergent and discriminant validity, incremental validity beyond related constructs, and measurement invariance across relationship status, gender, and sexual orientation. Short-form versions of the RoCh scale had good psychometric properties. Study 4 evaluated the scale among married couples (n = 134 couples), establishing dyadic measurement invariance and convergence between partners’ reports. Romantic chemistry emerged as a shared, couple-level construct associated with relationship outcomes, such as commitment and sexual frequency. Findings support the RoCh scale as a reliable and valid measure of romantic chemistry, a construct whose role in fostering high-quality relationships warrants further investigation.