The psychosocial maturity scale (PSM) described in several earlier papers is a self-report questionnaire. It is vulnerable, as are other questionnaires of this type, to respondents' wishes to present themselves in a socially desirable light. In this study, scores on two social desirability scales are examined in relation to PSM. Correlations between the two variables are very modest, and the trend in the direction mean scores from grade 5 to grade 11 is different for social desirability and PSM; mean scores on the former variable decline, whereas mean scores on the latter increase markedly. These findings indicate that the PSM scale measures a set of attitudes which are distinct from the disposition to "fake good." (Author)