This study assessed age and sex differences in the prevalence and incidence rates of syndromal social anxiety (SSA), as well as the predictive role of depressive symptoms and stressful life events on the development and persistence of SSA. A sample of 1,439 young people, between 11 and 14 years of age, was assessed twice within a 12-month interval. No age differences were found. Girls had a significantly higher prevalence of SSA than boys, but there was no sex difference for incidence rate. Depressive symptoms did not play a significant role in either the development or the persistence of SSA, whereas SSA predicted the development of depression. Stressful life events played a significant role in SSA's development but not in its persistence. (Contains 3 footnotes and 4 tables.)