The paper reports findings of a three year longitudinal study of high school student social and political attitudes. The hypothesis was that openness of social studies classroom climate would be related to change in social and political attitudes toward school and, to a lesser extent, to change in general social and political attitudes. Attitude data were collected each spring from students in ten midwestern high schools from March 1974 to April 1976. The four basic attitudes were trust, integration, confidence, and interest. Classroom climate was assessed through student perceptions of three characteristics: frequency of controversial issues exposure, range of viewpoints encouraged, and openness of student opinion expression. Each climate variable was found to be related directly to each school-related variable for the three-year period, with more open perceived classroom climate associated with more positive school attitudes of trust, integration, confidence, and interest. Overall across-time attitude trends show a decrease in political confidence, possibly an effect of the Watergate scandal. Implications of the study are that controversial issues should be included in social studies curricula, and that teacher objectivity enhances positive student attitudes. (Author/AV)