Media effects researchers try to isolate elements of the communicator, channel, or message that explain the impact messages have on receivers. One view of this process emanates from a mechanistic perspective and assumes direct influence on message recipients. A mechanistic perspective sees audience members as passive and reactive, focuses on short-term, immediate, and measurable changes in thoughts, attitudes, or behaviors, and assumes direct influence on audiences. Some have suggested other elements intervene between media messages and effects. Klapper (1960), for one, questioned the validity of mechanistic approaches. His phenomenistic approach proposed that several elements intercede between a message and a response so that, in most instances, media messages that are intended to persuade actually reinforce existing attitudes. These mediating factors include individual predispositions and selective perception processes, group norms, message dissemination via interpersonal channels, opinion leadership, and the free-enterprise nature of the media in some societies. Accordingly, we could argue (a) by themselves, media typically are not necessary or sufficient causes of audience effects, and (b) a medium or message is only a single influence in the social and psychological environment, although it is an important crucial one. A PSYCHOLOGICAL PERSPECTIVE According to uses and gratifications, a medium or message is a source of influence within the context of other possible influences. Media audiences are variably active communicators, rather than passive recipients of messages. The perspective underscores the role of social and psychological elements in mitigating mechanistic effects, and sees mediated communication as being socially and psychologically constrained. Rosengren (1974) wrote that uses and gratifications rests on a mediated view of communication influence, whereby individual differences constrain direct media effects. Therefore, to explain media effects, we must first understand the characteristics, motivation, selectivity, and involvement of individual communicators. Uses and gratifications, then, is a psychological communication perspective. It shifts the focus of inquiry from a mechanistic perspective's interest in direct effects of media on receivers to assessing how people use the media: "that is, what purposes or functions the media serve for a body of active receivers" (Fisher, 1978, p. 159). The psychological