The two-step flow of communication hypothesis was first formulated by Paul F. Lazarsfeld and his colleagues in their classical study on the 1940 American presidential election (1944). It states that there is usually no direct influence of the mass media on the general public. Rather, “ideas often flow from radio and print to the opinion leaders and from them to the less active sections of the population” (Lazarsfeld et al. 1944, 151). This assumption, challenging the popular idea of strong direct media effects on the public, turned out to be one of the most influential ideas in communication research from the 1940s to at least the 1960s. While recent research has contradicted the original hypothesis in its rigid form, many of its underlying ideas have stimulated fruitful further research. This holds especially true for the concept of opinion leadership and the analysis of social networks.
In The people’s choice, Lazarsfeld and colleagues found that 17 percent of the voters had changed their voting intentions during the campaign. Two thirds of all voters mentioned radio and newspaper as a “helpful source” for making their voting decisions. From today’s point of view, these results seem to indicate relatively strong media effects. Nevertheless, the authors had expected to find much stronger effects – as had been found by several earlier studies. Consequently, they tried to explain why mass media may be less powerful than commonly assumed. In doing so, they found two explanations. First, voters prefer to be exposed to media content that confirms their own political ideas. Therefore, their opinions are rather reinforced than changed by the media. Second, the flow of ideas from the mass media to the general public is not direct but rather involves two steps: a first step from the media to so-called opinion leaders, and a second step from them to so-called followers. Opinion leaders can be found on every level of society and do not differ much in their characteristics from other people. But they are more often exposed to mass media and more often try to convince others of their political ideas. However, because the study was not designed to examine the flow of communication more closely, it remained unclear whether there really was a two-step flow.
In the Rovere study, Merton (1949) suggested that opinion leadership is not a general characteristic of a person but rather limited to specific issues. He developed several typologies, e.g., the distinction between local and cosmopolitan opinion leaders. Both differ in their media consumption as well as in their areas of influence. In the Decatur study, Katz and Lazarsfeld (1955) further developed this idea. They distinguished opinion leadership in four areas of decision-making: marketing, fashion, public affairs, and movie-going. Generally, the results confirmed the assumptions of the two earlier studies: opinion leadership was more or less restricted to one of the four areas, and opinion leaders were more often exposed to mass media than followers. Respondents who changed their opinions or behavior reported more often that they had been convinced by interpersonal communication than by the mass media. In the drug study, Menzel and Katz (1955) established the method of network analysis by asking doctors to name the three colleagues they most often met, talked to, and got advice from. By mapping all contacts in a social network, authors identified opinion leaders and followers. Again, the study confirmed most results of earlier research. On the other hand, the idea of a two-step flow of communication was not clearly supported. Opinion leaders frequently mentioned other opinion leaders as sources of information. This finding suggested that the flow of communication might be rather multistep than two-step.
Taken the assumptions of the early studies together, the two-step flow of communication model consists of at least five more or less explicitly stated hypotheses. (1) Most people are not directly exposed to the mass media. They are rather informed via interpersonal communication by so-called opinion leaders. (2) Opinion leaders are much more exposed to mass media and much more engaged in active communication than the general public is. (3) Opinion leaders not only inform the followers, but also transmit the content of the mass media to them. Otherwise, instead of a two-step flow of communication, there was concurring information by interpersonal and mass communication. (4) The general public is not only informed but also influenced by opinion leaders. The information given by opinion leaders leads to changes in opinions or behavior. (5) Opinion leaders are no passive gatekeepers of media information. They transmit media content biased through their own opinions. Otherwise, the two-step flow of communication hypothesis would not be challenging the idea of strong media effects. Just the opposite was the case: conveying media information to those who are not exposed to media themselves means increasing media effects.
In recent research these hypotheses have often been disentangled and studied separately. Generally, three types of studies can be distinguished. First, studies on the diffusion of news deal with the flow of information from the mass media to the general public without taking the concept of opinion leadership into account. Second, studies on opinion leaders deal with the question of how opinion leadership can be measured, the structure of social networks, and the characteristics of opinion leaders without taking media effects into account. Third, studies on the sources of public opinion compare the effects of interpersonal and mass communication without analyzing the flow of information.
Diffusion Of News
The assumption that most people are not directly exposed to mass media but rather informed by interpersonal communication has been proven to be wrong by several recent studies on news diffusion. Nowadays, in western democracies about 80–90 percent of adults are exposed to any kind of media news on an average weekday. Comparing the primary source of news in 34 countries worldwide, Plasser & Plasser (2002) found that in almost all countries under examination, the primary source of news is television, followed by newspaper. On average, less than five percent of respondents say that they are primarily informed by interpersonal communication.
Besides these general findings, since 1945 several studies on the diffusion of single news events have been conducted. In those studies, respondents are asked when and from which source they first heard about an event. They show quite different results, depending on the salience of the events under examination. In the case of extremely high-salience news events like Kennedy’s assassination or the Challenger explosion in 1986, information diffuses rapidly and is conveyed to a significant number of people via interpersonal communication. In the case of relatively low-salience news events, information reaches fewer people and is conveyed almost exclusively by mass media. The reason for that finding, probably, is that only in the case of high-salience news events is interpersonal communication stimulated. Indeed, several studies on news diffusion show that people start talking to others about an event after being informed about it by the mass media. Those discussions were much more likely when the event was highly salient. Consequently, sometimes a two-step flow in news diffusion is quite likely – but only under extreme conditions, which seldom occur.
Role Of Opinion Leaders
The idea of opinion leadership was revived during the 1980s and 1990s by developing new methods of measurement. Besides network analysis, the “strength of personality scale” has become a frequently used tool for measuring opinion leadership. Instead of directly asking people whether they influence others, ten less obvious items (e.g., “I like to assume responsibility”) are used to identify opinion leaders. As in the early studies, opinion leaders, classified by recently developed methods, turn out to be highly exposed to mass media and actively engaged in interpersonal communication. They are located in central positions in social networks and many others report that they are influenced by them.
On the other hand, recent studies on opinion leadership suggest that the concept of a two-step flow of communication is oversimplified. First, opinion leaders engage in interpersonal communication with followers as well as with other opinion leaders. This finding points to a multistep flow of communication. Second, in the communication flow regarding most issues, a clear majority is neither opinion leader nor follower. Instead, they do not engage in interpersonal communication at all. Consequently, they have to rely on media information.
Sources Of Influence
Today, there is clear evidence that mass media influence people’s opinions and behavior in many ways. The same holds true for interpersonal communication. The crucial question is how the effects of both sources are related. This question relates to both steps of the two-step flow model. Concerning the first step, the question is how adequately opinion leaders understand the information received from the mass media. Only in cases where they understand and remember media content correctly are they able to convey it to others.
Several studies on learning from the news suggest that most people tend to quickly forget at least the details presented by the media. In the event of this holding true for opinion leaders too, a two-step flow of communication is quite unlikely. Concerning the second step, the question is how opinion leaders transmit media content to others. While several studies on interpersonal communication show that people frequently talk about media content, it remains unclear whether they convey it neutrally or in a manner that is biased by their own opinions. Only in the latter case can interpersonal and mass communication be regarded as contrasting influences. If people convey media content in a more or less unbiased way to others, interpersonal communication is not an independent source of influence. Rather, its effects should be regarded as an expansion of media effects.
Thus far, only a few studies have dealt with these questions. By using aggregate data, Brosius and Weimann (1996) found evidence for several models of influence – in this case agenda-setting effects. Under some conditions, the media agenda, first, influenced the agenda of early recognizers – in the authors’ terms – or a sub-group of opinion leaders. In a second step, the early recognizers’ agenda influenced the public’s agenda. While this finding is in line with the two-step flow model, more often another flow of influence occurred. First, the agenda of early recognizers influenced the media agenda. Then, the media agenda influenced the agenda of the general public.
Still, there is no test of the complete two-step flow model on an individual basis. Such a test would require a complex research design, including detailed analyses of media content and interpersonal discussions as well as surveys of individual media exposure, engagement in discussions, and opinion changes over time. Carrying out a complex study of this kind seems almost impossible. Nevertheless, more detailed research on the role of interpersonal communication as a mediator of media effects is needed.
- Brosius, H.-B., & Weimann, G. (1996). Who sets the agenda? Agenda-setting as a two-step flow. Communication Research, 23, 561–580.
- Katz, E., & Lazarsfeld, P. F. (1955). Personal influence. New York: Free Press.
- Lazarsfeld, P. F., Berelson, B., & Gaudet, H. (1944). The people’s choice: How the voter makes up his mind in a presidential campaign. New York: Duell, Sloan and Pearce.
- Menzel, H., & Katz, E. (1955). Social relations and innovation in the medical profession: The epidemiology of a new drug. Public Opinion Quarterly, 19, 337–352.
- Merton, R. K. (1949). Patterns of influence. In P. F. Lazarsfeld & F. Stanton (eds.), Communication research. New York: Harper, pp. 180–219.
- Plasser, F., & Plasser, G. (2002). Global political campaigning: A worldwide analysis of campaign professionals and their practices. Westport, CT: Praeger.
- Rogers, E. M. (2000). Reflections on news event diffusion research. Journalism and Mass Communication Quarterly, 77, 561–576.
- Weimann, G. (1994). The influentials: People who influence people. New York: State University of New York Press.