APA Dictionary of Psychology

a general socioeconomic class in the middle of a social hierarchy. In economic terms, it is sometimes held to consist of an upper middle socioeconomic class of professionals, administrators, and middle-level executives and a lower middle socioeconomic class of shopkeepers, artisans, clerical staff, and service workers. The latter, although still relatively materially privileged, are often not positioned as advantageously in the power structure of a society. Also called bourgeoisie. See social class; socioeconomic status.