Although emotional expressivity figures prominently in several theories of psychological and physical functioning, limitations of currently available measurement techniques impede precise and economical testing of these theories. The 17-item Emotional Expressivity Scale (EES) was designed as a self-report measure of the extent to which people outwardly display their emotions. Reliability studies showed the EES to be an internally consistent and stable individual-difference measure. Validational studies established initial convergent and discriminant validities, a moderate relationship between self-rated and other-rated expression, and correspondence between self-report and laboratory-measured expressiveness using both college student and community populations. The potential for the EES to promote and integrate findings across diverse areas of research is discussed.