The presence of homophily is frequently found as a core feature of social networks. The principle that “similarity breeds connection” results in personal networks skewed towards homogeneity along numerous demographic and interpersonal lines (McPherson, Smith-Lovin, & Cook, 2001).

Festinger argues that homophily is a direct result of social influence: beliefs are only coherent through a process of social comparison and therefore people “tend to move into groups which, in their own judgment, hold opinions which agree with their own” (Festinger, 1954). The problem of embeddedness  – that people’s attempts at purposive action are embedded in concrete, ongoing systems of social relations – is inherent in this argument.

Reviewing the literature on social comparison, Festinger finds that individuals’ beliefs are malleable to social influence because the beliefs of others serve as guideposts in forming one’s own opinion. Foreshadowing Sunstein’s ‘law of group polarization’ (Sunstein, 1999), Festinger argues that this process of forming beliefs through social comparison is a primary driver of what he calls “social quiescence” (Festinger, 1954). This in turn serves as a driver for homophily, as people self-select out of groups unable to reach social quiescence, instead selecting into groups that more appropriately “satisfy their drive for self evaluation.”

Within the political domain, Lazarsfeld pioneered an understanding of public opinion as a process of social influence: a process driven significantly by personal conversations and everyday talk. While earlier understandings took media to be the primary source of political information and influence (Lippmann, 1922), Lazarsfeld suggests a “two-step flow” of communication: ideas and opinions may originate in media, but they flow first to opinion leaders.

What we call public opinion is then formed in a second step when these leaders disseminate information along lines of social influence. Importantly, opinion leaders generally exert greater social power than media, due to the many “psychological advantages” personal contacts have in exerting political influence (Lazarsfeld, Berelson, & Gaudet, 1948). These advantages include trust, conflict avoidance, and “persuasion without conviction,” e.g., the ability to actually take someone to the polls.

Perhaps most interesting for deliberative theory, however, is Lazarsfeld’s argument that “the weight of personal contacts upon opinion lies, paradoxically, in their greater casualness and non-purposiveness in political matters” (Lazarsfeld et al., 1948). In purposive political talk, individuals engage critically and intentionally, mentally prepared with “armor against influence.” Everyday talk, on the hand, catches us unprepared.

The passive exposure that comes from casual conversations presents a pervasive opportunity for powerful personal influence. We again see this argument manifest in Mutz and Mondak’s study of the workplace as a site for cross-cutting political dialogue. Workplaces may have a smaller proportion of political conversations than other settings, but the sheer volume of casual conversations makes workplaces as a key setting for political contact (Mutz, 2002).

Such public-minded talk ceased to be the sole purview of the Greek agorá long ago: when democracy is a way of living, as Dewey writes, even the most seemingly mundane sites of human interaction become critical elements of the deliberative system.