Development of a scale measuring genetic variation related to expressive control

It has been theorized that a substantial genetic component underlies the Self-Monitoring Scale. The identity of this component, however, is not yet known. In order to identify and better understand it, a more precise measure of the component is required. The present research attempted to (a) identify an axis of the self-monitoring two-factor space with maximum genetic variance; and (b) bootstrap a scale more highly correlated with this genetic maximum than is the Self-Monitoring Scale using twins. Evaluation of the new scale against criteria of validity indicates that scale construction was reasonably successful. The new measure had a cross-validated monozygotic twin intraclass correlation of .76 and a dizygotic twin intraclass correlation of .16. This work yields a new research tool and suggests a new approach to personality assessment. Correlates of the new measure as well as theoretical and methodological issues relevant to the measurement of a latent genetic entity are discussed.