Mass Media

Two Step Flow Theory

influence of media messages

History and Orientation

The two-step flow of communication hypothesis was first introduced by Paul Lazarsfeld, Bernard Berelson, and Hazel Gaudet in The People's Choice, a 1944 study focused on the process of decision-making during a Presidential election campaign. These researchers expected to find empirical support for the direct influence of media messages on voting intentions. They were surprised to discover, however, that informal, personal contacts were mentioned far more frequently than exposure to radio or newspaper as sources of influence on voting behavior. Armed with this data, Katz and Lazarsfeld developed the two-step flow theory of mass communication.

Core Assumptions and Statements

This theory asserts that information from the media moves in two distinct stages. First, individuals (opinion leaders) who pay close attention to the mass media and its messages receive the information. Opinion leaders pass on their own interpretations in addition to the actual media content. The term ‘personal influence’ was coined to refer to the process intervening between the media’s direct message and the audience’s ultimate reaction to that message. Opinion leaders are quite influential in getting people to change their attitudes and behaviors and are quite similar to those they influence. The two-step flow theory has improved our understanding of how the mass media influence decision making. The theory refined the ability to predict the influence of media messages on audience behavior, and it helped explain why certain media campaigns may have failed to alter audience attitudes an behavior. The two-step flow theory gave way to the multi-step flow theory of mass communication or diffusion of innovation theory.

Conceptual Model


Source: Katz & Lazarsfeld (1955)

Favorite Methods

To be added.

Scope and Application

All kinds of mass media can be researched with this theory (TV, radio, internet).


To be added.


Key publications

See also: Hypodermic Needle Theory, Diffusion of Innovations Theory
See also Mass Media