Co-development of internalizing and externalizing behaviors during middle childhood and potential moderators of the process

Child internalizing and externalizing problems co-vary during development and lead to maladjustment outcomes, such as substance abuse, academic failure, antisocial behaviors and psychopathology. The proposed study aims to examine the co-development process of internalizing and externalizing problems during middle childhood and the potential moderators of this reciprocal relationship. Children and their families recruited in the Study of Early Childhood Care and Youth Development (SECCYD) constitute the sample of the current study. Participants in the study were recruited from nine states in the United States and followed from birth to adolescence. Though a few studies have examined the developmental trajectories of internalizing and externalizing problems over time, the findings are not consistent in terms of the directions of the relationship and very few have examined individual difference in the co-development process. To address this gap in knowledge, two moderating effects are examined, with one moderator being time-invariant, i.e., children's gender, and the other moderator being time-variant, i.e. parent-child conflicts. Longitudinal growth modeling and longitudinal difference score modeling are used to examine the dynamic relationship and the moderating effects. Comparisons of the two approaches are made with respect to the specific hypotheses of change tested by each model, model convergence, parameter and fit estimates, and the interpretation of the results.