This study compared the effects of four experimental treatments on levels of expectancy or aspiration of 80 disadvantaged and non-disadvantaged boys and girls. Levels of expectancy were more discrepant from previous performance in conditions perceived as chance regulated, and in those outcomes actually controlled by chance. More unusual shifts in expectancy, down after success, were made under chance conditions. Disadvantaged girls perceived themselves as most powerless in influencing their own reinforcements, whereas the disadvantaged boys had a less external or chance of orientation. (Author/DM)