Longitudinal dynamics of trait emotional intelligence: Measurement invariance, construct stability, and mean level change from late childhood to adolescence

Emotional intelligence (EI) encompasses abilities (ability EI; AEI) and self-perceptions (trait EI; TEI) related to the expression, understanding, and management of emotions. Research on its developmental dynamics remains heavily weighted by the AEI perspective, whereas TEI has received virtually no attention in the developmental literature. This is a major oversight, as the two EI components are conceptually distinct and contribute independently to the prediction of important outcomes. Using multi-wave data from the Canadian National Longitudinal Survey of Children and Youth, this project examined rank-order stability (Study 1) and mean-level change (Study 2) in TEI over a 6-year period from late childhood (age 10-11) to adolescence (age 16-17). Longitudinal measurement invariance of the TEI assessment was also tested (Study 1). Longitudinal mean and covariance structures models (Study 1) and latent growth curve models (Study 2) were fitted to the data from 773 children (51% girls) who completed the Emotional Quotient Inventory--Youth Version Brief form at four biannual waves. Principles from the self-concept literature were used to outline an integrative theoretical framework within which the developmental dynamics of TEI could be studied and understood. Study 1 found that three of the four TEI domains could be measured consistently and reliably over time, and that individual differences in these domains became progressively more stable with age. Contrary to the maturity principle guiding the development of AEI, Study 2 found that mean-level changes in TEI followed a curvilinear trajectory characterizing the development of self-concepts: EI self-perceptions declined between late childhood and early adolescence and then increased later in adolescence. These findings provide, for the first time, important validity evidence for the TEI construct as developmentally distinct from AEI and developmentally similar to self-concept. From an applied standpoint, this implies that enhancing EI abilities alone may not necessarily result in concomitant increases in EI self-concepts, and vice versa. Instead, both AEI and TEI may need to be targeted to maximize the effectiveness of intervention efforts. From a theoretical standpoint, the conceptual link between TEI and self-concept theories suggests that other properties of self-concepts might also generalize to TEI -- an important avenue for future research.