Twelve hundred and twenty-five elementary school children in Israel from five schools responded to a questionnaire assessing self-esteem, locus-of-control, and classroom social climate. Data obtained from the measures for each of these dependent variables were compared on three independent variables of school grade (4 through 8), socioeconomic status (lower and middle-class) and sex. A positive trend appeared in the data for self-esteem, an even more striking positive development emerged in the findings for locus-of-control, but a negative development with age was found in the pupils' perception of their classroom social climate. Thus, affective personality variables and children's perception of the school social environment were found to follow divergent patterns of development. Particularly striking was the fact that middle-class children were generally higher on personality measures than were lower-class children but the latter group had a more positive perception of the classroom climate than did the former group.