The Stability of Self Scale has been used to infer the stability of self-concept from responses collected on a single occasion. Using the large, nationally representative Youth in Transition data for 10th grade boys in public high schools in 1966, Stability of Self responses were related to the variability in self-esteem responses collected in 4 consecutive years. Data were from 2,213 10th graders, 1,886 11th graders, 1,799 12th graders, and 1,505 high school graduates. Within-subject variability of self-esteem responses was unrelated to Stability of Self responses, and the correlations among esteem ratings were very similar for students having high, medium, and low Stability of Self responses. Consistent with other research considering short-term stability of esteem, this investigation indicates that stability of esteem cannot be accurately inferred from Stability of Self responses collected on a single occasion. Four tables present study data. Two figures illustrate the study, and an appendix shows the wording of items on the Stability of Self Scale and the Self-Esteem Scale. Thirty references are included. (Author/SLD)