Consistent with a Diathesis × Stress model, it was hypothesized that anxious solitude (individual vulnerability) and the middle school transition (environmental stress) would jointly predict peer exclusion and victimization trajectories. Youth (N = 688) were followed from 3rd through 7th grade, with the middle school transition in 6th grade.…

This study uses intraindividual variability and change methods to test theoretical accounts of self-concept and its change across time and context and to test the developmental implications of this variability. The 5-year longitudinal study of 541 youths in a rural Pennsylvania community from 3rd through 7th grade included twice-yearly assessments…