In 1922 Walter Lippman , newspaper columnist, first posed the idea that the mass media shapes public perception with images. Lippman's notion, based on the public's limited first-hand knowledge of the real world, created the foundation for what has come to be known as agenda-setting. The agenda-setting theory maintains the media plays an influential part in how issues gain public attention. Conceptualized over time, agenda-setting is the dynamic process "in which changes in media coverage lead to or cause subsequent changes in problem awareness of issues" (Brosius & Kepplinger, 1990, p. 190; Lang & Lang, 1981). Bernard Cohen's statement in 1963 predicted "the press may not be successful much of the time in telling people what to think, but it is stunningly successful in telling its readers what to think about" (p.13). Whether social or political, local or national, public issues are generated by the media. Consumers not only learn about an issue "but also how much importance is attached to that issue from the amount of information in a news story and its position" (McCombs & Shaw, 1972, p. 176). McCombs and Shaw's study of mediated affects on the 1968 presidential campaign nullified previous assumptions that information and how it is presented has an attitudinal effect inducing behavior changes. Their groundbreaking efforts focused on issue awareness and relevance not behavior and attitude, concluding "the mass media exerted a significant influence on what voters considered to be the major issues of the campaign" (Infante, et al., 1997, p. 366).
Media drives agenda. Funkhouser (1973) focused his attention on the major issues for each year in the 1960s and further concluded that media agenda drives public agenda, and real-world indicators are less strongly associated with issue salience and media attention (Funkhouser, 1973; Dearing & Rogers, 1996). Triggering devices, surmise Cobb and Elder (1972), cue action during a point in time and propel an issue up the policy agenda. Examples of this phenomena are the War on Drugs campaign; the 1989 Exxon Valdez oil spill and accompanying environmental issues; and the 1984 Ethiopian famine where NBC broadcast the first pictures of starving children on the evening news triggering massive news coverage for the next 10 months (Dearing & Rogers, 1996). Ironically, during the time of the Ethiopian crisis, Brazil was simultaneously experiencing the worst drought in its history. While the United States and other international governments provided aid, musicians organized benefits raising tens of millions of dollars for food aid, and the news media scrambled to cover the Ethiopian famine, the Brazilians suffered without "international fanfare" (Dearing & Rogers, 1996, p. 70). Logistics proved to be the Brazilians' downfall because "feeding stations were spread across a vast territory, rather than being crowded together, as in Ethiopia," where children lay dying together in concentrated areas convenient for news cameras (Dearing & Rogers, 1996, p. 69). Without pictures there was no story (Boot, 1985).
Empirical research of agenda-setting theory and broadcast content shows issue status and increased public concern are particularly influenced by television's "visual realism and affective appeal" (Ibelema & Powell, 2001, p. 42). "People are more likely to believe what they see. And attractive people as reporters and anchors are much more on display on television than in newspapers" (p. 42).
Media influence. Gitlin (1980) suggests that mass media influence has become the principle distribution system of ideology. People are only familiar with their own "tiny regions of social life" (Gitlin, 1980, p. 1), and that the mass media brings simulated reality into their lives and people find themselves relying on those sources to provide a conceptualized image of the real world.
While agenda-setting theory has its critics, the...