The Structure of Achievement and Behavior Across Middle Childhood

This research uses data from the National Longitudinal Survey of Youth (NLSY) to describe and model developmental trajectories across middle childhood. Our sample consists of approximately 1,000 children of NLSY women who were age 6-7 in either 1986 or 1988. Assessments of PIAT math and reading scores and the mother-reported Behavior Problem Index in 1986, 1988, 1990 and 1992 provide data for middle-child trajectories of children age 6-7 in 1986. Assessments in 1988, 1990, 1992 and 1994 provide data for children age 6-7 in 1988. We use the raw-score form of these data to estimate LISREL-based models of the autoregressive structure of these data. As with other samples, average math and reading achievement trajectories are parabolic for NLSY children, with scores increasing at a decreasing rate over this period. Average behavior-problem scores are basically flat. Behind these average shapes is extreme diversity in level, and in some cases, slopes of, individual trajectories, and a pronounced tendency for above average changes between two assessments to be followed by opposed-signed changes in the subsequent period. Estimates from our structural models showed great heterogeneity in the average level of achievement and behavior for all three outcomes and heterogeneous slopes for reading scores as well. Boys but not girls were found to have heterogeneous slopes for math and behavior problems, while girls but not boys showed a significantly higher degree of persistence if shocked off of their long run trajectories.