A growing number of school systems use self-report surveys to track students' social-emotional development as a tool to inform policy and practice. We use the first large-scale panel survey of social-emotional learning (SEL) to simulate how four constructs--growth mindset, self-efficacy, self-management, and social awareness--develop from Grade 4 to Grade 12 and how these trends vary by gender, socioeconomic status, and race/ethnicity among students participating in the survey for two consecutive years. With the exception of growth mindset, self-reports of these constructs do not increase monotonically as students move through school; self-efficacy, social awareness, and to a lesser degree self-management decrease after Grade 6. Female students report higher self-management and social awareness than males, but lower self-efficacy relative to males in middle and high school. Economically disadvantaged students and students of color report lower levels of each construct. These patterns highlight the need for policymakers to interpret changes in students' self-reports over time in light of normative trends in social-emotional development and illustrate how such self-reports may nonetheless be used to set priorities and target interventions and resources.