The present paper outlines the relevance of the states of cheerfulness, seriousness, and bad mood for research on the emotion of exhilaration. Definitions of the concepts are undertaken and the construction strategy for the State-Trait-Cheerfulness-Inventory (STCI) is outlined. The pilot version with 40 items was administered to altogether more than 800 subjects. Empirical analyses of the concepts included the study of the homogeneity of the items in both inter- and intraindividual variation, the identification of sub-clusters, and the demonstrations of the sensitivity of items for mood alterations. The standard state form with 10 items per scale, i.e. the STCI-S was developed based on the data of a construction sample (N = 595) utilizing five criteria for the selection of items. The internal consistency of the scales proved to be satisfactory in various independent subject samples and the expected scale intercorrelations emerged. The factor structure of the items appeared to be highly generalizable across different sources of variation, gender, nationality (U.S.A. vs Germany), and time spans covered. A joint factor analysis of the state and trait items yielded factors of cheerfulness, seriousness, and bad mood both as traits and states with the homologous concepts correlating positively. Convergence of states and traits was also obtained for peer-evaluation data. Finally, the possible range of variation in the three scales across different (experimentally manipulated or naturally occurring) conditions was explored. (C) 1997 Elsevier Science Ltd.