<P> The "magic bullet" or "hypodermic needle theory" of direct influence effects was based on early observations of the effect of mass media, as used by Nazi propaganda and the effects of Hollywood in the 1930s and 1940s . People were assumed to be "uniformly controlled by their biologically based' instincts' and that they react more or less uniformly to whatever' stimuli' came along". The "Magic Bullet" theory graphically assumes that the media's message is a bullet fired from the "media gun" into the viewer's "head". Similarly, the "Hypodermic Needle Model" uses the same idea of the "shooting" paradigm . It suggests that the media injects its messages straight into the passive audience . This passive audience is immediately affected by these messages . The public essentially cannot escape from the media's influence, and is therefore considered a "sitting duck". Both models suggest that the public is vulnerable to the messages shot at them because of the limited communication tools and the studies of the media's effects on the masses at the time . It means the media explores information in such a way that it injects in the mind of audiences as bullets . </P> <P> The "magic bullet" and "hypodermic needle" models originate from Harold Lasswell's 1927 book, Propaganda Technique in the World War . Recent work in the history of communication studies have documented how the two models may have served as strawman theory or fallacy or even a "myth". Others have documented the possible medical origins of the metaphor of the magic bullet model . </P> <P> The phrasing "hypodermic needle" is meant to give a mental image of the direct, strategic, and planned infusion of a message into an individual . But as research methodology became more highly developed, it became apparent that the media had selective influences on people . </P> <P> The most famous incident often cited as an example for the hypodermic needle model was the 1938 broadcast of The War of the Worlds and the subsequent reaction of widespread panic among its American mass audience . However, this incident actually sparked the research movement, led by Paul Lazarsfeld and Herta Herzog, that would disprove the magic bullet or hypodermic needle theory, as Hadley Cantril managed to show that reactions to the broadcast were, in fact, diverse, and were largely determined by situational and attitudinal attributes of the listeners . </P>

The hypodermic needle model gained prominence in response to what