Vansteelandt, K., Van Mechelen, I., & Nezlek, J. B. (2005). The Co-occurrence of emotions in daily life: A multilevel approach. Journal of Research in Personality, 9, 325-335.
Zelenski and Larsen (2000) argued that a dimensional model may apply to emotional traits whereas a discrete model may apply to emotional states. This implies that between-subjects correlations among emotions of the same valence should be positive whereas within-subject correlations among these emotions should be negative. Zelenski and Larsen found (partial) support for such a distinction; however, their study suffered from some methodological shortcomings in terms of the data collection and data analysis. The present study remedied these problems by assessing momentary emotions using Experience Sampling Methodology (ESM) and by analyzing the data using a multivariate random coefficient model that was able to estimate both between-subjects and within-subject correlations directly. The results suggest that a dimensional model applies to emotional traits. For emotional states, a discrete model applies to emotions of different valence whereas emotional blending occurs for emotions of the same valence.