Towards a dynamic, idiographic approach to describing, explaining, and enhancing the development of SEL

Human development involves intraindividual changes across the life span. Developmental changes may involve instances of change common to all individuals (nomothetic change), change common to only some groups of individuals (differential change), and change specific to an individual (idiographic change). All three types of change must be measured to obtain a holistic and integrated understanding of any facet of human development. To date, most studies of the development of social and emotional learning (SEL) skills have focused on assessing nomothetic and differential change. The analysis of data derived from this research is variable-focused, and longitudinal studies with such a focus typically do not have enough time points to model intraindividual trajectories with sufficient power. Such trajectories require analysis wherein each individual is compared to themselves across time (ipsative analyses). Change-sensitive measures used within intensive longitudinal designs and analyses are suitable for ipsative analyses of participants and enable direct comparisons of whether intraindividual trajectories are reflected in group data. We discuss research findings reflecting that meaningful idiographic changes are not reflected in group data. We also argue that future studies of SEL should integrate idiographic data with differential and nomothetic data in the service of understanding the holistic development of SEL.