An actor's social position is defined by variables that determine the actor's opinions in a domain of issues. The variables may include socioeconomic characteristics (gender, ethnicity, education, income, occupation), material conditions (economy, demography, ecology), and cultural items (beliefs, norms, rules); the variables also may include opinions of significant others. The former set of variables describe exogenous effects on opinions and determine actors' initial opinions, as in Eq. (2.1). The latter set of variables describe endogenous effects on opinions, i.e., the response of actors to the opinions of others, as in Eq. (2.2). The different social positions of actors are based on individual differences in actors' profiles of exogenous status characteristics (X) or endogenous interpersonal influences (W).

Actors with identical status characteristics are not necessarily subject to identical interpersonal influences.