Development of self-conscious emotions such as embarrassment are thought to depend on the emergence of a sense of self as distinct from other. This longitudinal and cross-sectional study sought to replicate the association between a self-referential visual self-recognition task and embarrassment, and to extend the understanding of the interrelations between pronoun production and emergence of "other" in imitative pretend play tasks as indicators of self-development. Toddlers' embarrassment reactions (in response to an over-complimenting experimenter), self-recognition, and complexity in imitative pretend play were assessed in a laboratory setting when subjects were 19, 22, 25, and 28 months of age. Pronoun production was assessed through maternal reports when the subjects were 18 and 24 months old. Participating were 161 toddler twins who were part of an ongoing longitudinal study of emotional development. The cross-sectional sample size ranged from 51 to 64, while longitudinal sample size with listwise deletion across all four time points was 30. The findings provided very limited support for the hypothesis that the acquisition of a distinct sense of self is associated with embarrassment reactions as they were assessed. The findings did strongly suggest that development of complexity in pretend play, self-recognition, and embarrassment run largely parallel to each other, with different rates of change. Relations between pronoun production and embarrassment were mostly mixed: some associations supported and some contradicted the developmental priority of pronoun production as a measure of self-development over embarrassment. (KB)