Expectation states theory is a well-established, ongoing research program investigating various aspects of group interaction. The focus is on small, task-oriented groups; the central interest is in both the processes through which group members assign levels of task competence to each other and the consequences this assignment has for their interaction. Originating as a single theory developed by Joseph Berger (1958), expectation states theory has grown to include various branches sharing a core of basic concepts, definitions, and propositions about group interaction processes, as well as methodological and metatheoretical assumptions. Thus, the program in fact contains not just one theory but several. (Unless otherwise specified, the expression "expectation states theory" refers here to the entire program rather than to any particular theory within it.) Expectation states theory has received strong support from extensive empirical research.

Two key concepts in the program are "status characteristics" and...