There are three theories on the role of news media in society. The hypodermic needle theory is the oldest. The minimal effect theory is the opposite. The subtle effects theory is the most modern and accepted.
Hypodermic Needle theory (Magic Bullet theory)
Hypodermic Needle Theory (aka Magic Bullet Theory) states that mass media has a direct, immediate, powerful and uniform effect on its audiences.
This conceptualizes people as passive receivers with an attitude of "whatever you tell me to do, I'm going to do." One example of this is the radio broadcast of War of the Worlds, where Orson Welles and a few actors broadcast radio announcements of a martian invasion that paralleled his book. Several hundred thousand people panicked, showing that even aliens landing on Earth can be injected via the media's hypodermic needle.
A second example of this is the Dr. Wortham's 1954 publication Seduction of the Innocent. Dr. Wortham asked retarded and delinquent children whether they read comic books. When a lot of them said yes, he concluded that comic books caused retardation and delinquency.
Minimal Effect theory
Minimal Effect Theory states that mass media has a minimal effect on political preferences.
This is the opposite of the hypodermic needle theory, and concludes that here are so many factors influencing public opinion that the media's influence is negligible. For example, researchers went to Elmira, OH -- an area where voting patterns were identical to the rest of the country. However, people had quite different responses to media feelings. Interpersonal relationships were most imperative.
A 1944 study titled The People's Choice found that response to campaign information activated some voters, reinforced loyalties among others and converted few voters. Interpersonal discussions had the strongest impact due to selective exposure. According to selective exposure, individuals tend to expose themselves to information compatible with their own views.
Subtle Effects theory
The Subtle Effects Theory is summarized by Cohen's 1962 quote, "The mass media may not be successful much of the time in telling people what to think, but the media are stunningly successful in telling their audience what to think about."
Via this, the media has agenda setting, priming and framing effects.
The priming effect is the process of making certain issues or attributes more salient and more likely to be accessed in forming opinions.
A major implication is that public opinion of leaders can be swayed. For example, subject can be primed to think about national defense or the environment before evaluating Jimmy Carter.
The agenda setting effect is where individuals place importance on issues that is proportional to the media's coverage of that issue. The agenda setting effect has a positive information function and a negative information function.
A positive information function, where citizens are kept informed about important issues and citizens can hold leaders accountable. The agenda setting effect also has a negative information function, where competing values clash: commercial values (audience = advertising) and journalistic values (substantive, personal issues).
A negative information function, exemplified by the media's increased coverage of crime in the 1990's. Crime was lessening, but gained heavier media coverage because it was found that if it bleeds, it leads. Crime stories simply garnered a larger audience, and crime became a more important social issue.
The framing effect encapsulates how interpretation of events evokes different interpretive schemes.
For example, public Klu Klux Klan rallies have two frames: "free speech" frame and "public safety" frame. Limits to framing effects are: credible sources, where people question the credibility of the source; and selective exposure, since people can only be framed by news outlets to which they expose themselves.
Shanto Iyengar found that if responsibility (or blame) can be placed, that also influences people's perception.
Episodic framing depicts concrete events that illustrate general issues. An example is news coverage of poverty that focuses on an individual with interviews and dramatic images. People usually place blame on this individual and are less sympathetic. The public considers the problem the individual, and the solution is likewise the individual.
Conversely, thematic frames present political issues and events in a general context. An example is news coverage of poverty that focuses on general trends, charts, graphs and experts. People have no individual to blame and thus are more sympathetic. The public considers the problem society and government as a whole, and the solution is likewise policy.
Framing presents a clash between journalistic and commercial values.
Most television coverage employs episodic framing because of its entertainment value. However, this poses a problem because episodic framing usually achieves the opposite of its intention. Instead of activating people, they instead just blame the individual featured in the episodic frame. Also, episodic framing does not support the hypodermic needle theory.
When people become unsympathetic to the episodic frame's featured individual, that is on their own volition. They are not being told to hate that individual -- in fact, the frame is trying to evoke sympathy and tenderness.