Development of a Scale Measuring Genetic Variation Related to Expressive Control


  • This research and preparation of this article were supported by a National Institute of Mental Health National Research Council postdoctoral traineeship to Steven W. Gangestad, and by a grant from the University of Minnesota Academic Computing Services and Systems. We extend special thanks to David Lykken for providing data collected as part of the Minnesota Twin Study and to David Lykken and Niels Waller for providing data collected as part of the Minnesota Twin Registry. Correspondence concerning this article should be addressed to Steven W. Gangestad, Department of Psychology, University of New Mexico, Albuquerque, NM 87131, or Jeffry A. Simpson, Department of Psychology, Texas A&M University, College Station, TX 77843.


ABSTRACT 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