Investigated were school children's recognition of social class distinctions, cues they used, and the relationship of their ideas about social class to other beliefs and attitudes about the social world. An ethnically mixed group of 201 male and female subjects participated in the study. Five age groups were represented: second, fifth, and sixth graders, considered separately; a combined eighth/ninth-grade group; and college students. Subjects sorted photographs of people into categories along a poor-to-rich dimension, gave reasons for their categorizations, and participated in an interview eliciting a wider range of beliefs and attitudes. Substantial agreement across grade levels was found in judgments about who was rich or poor. Young children emphasized external aspects of class differences and had difficulty imagining role changes. Older children also used external features but added psychological explanations; they thought upward mobiliity would be difficult due to external and internal limits. By adolescence, subjects saw the world as less flexible and thought it unlikely that they would change their socioeconomic status. Young subjects thought that rich and poor could be friends; older children saw barriers to such friendships. Children's feelings appeared to be involved in decisions made about people in the photographs; data also revealed relationships among notions about social class, likeability, and attractiveness. (Examples of photographs used are appended.) (RH)