Media influence is the actual force exerted by a media message, resulting in either a change or reinforcement in audience or individual beliefs. Whether a media message has an effect on any of its audience members is contingent on many factors, including audience demographics and psychological characteristics. These effects can be positive or negative, abrupt or gradual, short-term or long-lasting. Not all effects result in change; some media messages reinforce an existing belief. Researchers examine an audience after media exposure for changes in cognition, belief systems, and attitudes, as well as emotional, physiological and behavioral effects.
The influences of mass media (or 'media effects') are observed in various aspects of human life, from voting behaviors[2] to perceptions of violence,[3][4] from evaluations of scientists[5] to our understanding of others' opinions.[6] The overall influence of mass media has changed drastically over the years, and will continue to do so as the media itself develops.[7] In the new media environment, we have dual identities - consumers and creators. We not only obtain information through new media, but also disseminate information to wide audiences.[8][9][10]
Further, the influence of the media on the psychosocial development of children is profound. Thus, it is important for physicians to discuss with parents their child's exposure to media and to provide guidance on age-appropriate use of any media, including television, radio, music, video games and the Internet.[11]
There are several scholarly studies which addresses media and its effects. Bryant and Zillmann defined media effects as "the social, cultural, and psychological impact of communicating via the mass media".[12] Perse stated that media effects researchers study "how to control, enhance, or mitigate the impact of the mass media on individuals and society".[13] Lang stated media effects researchers study "what types of content, in what type of medium, affect which people, in what situations".[14] McLuhan points out in his media ecology theory that "The medium is the message."[15]