be communicated most effectively by authority figures or representatives of law enforcement agencies.
Generally speaking, the most effective communication sources are those that are viewed as trustworthy and as having expertise in the relevant behavioral domain (Eagley and Chaiken, 1993). In some cases, however, the similarity of the source with the audience is critical. For example, Bandura (1997) identified four sources for the development of self-efficacy beliefs: enactive mastery experiences, vicarious learning, persuasion, and one’s own physiological and affective states. Particularly in the case of vicarious learning (i.e., learning through seeing others perform or attempt to perform the behavior in question), the selection of the other (or “model”) is critical. The more one can “identify” with the model (i.e., see the model as similar to one’s self), the more one is likely to view the model’s attainments as diagnostic of one’s own capabilities.
Although a complete discussion of vicarious learning and modeling is beyond the scope of this chapter, our previous discussion shows that, in order to maximize the potential impact of a given message, the selection of a communication source is a complex process involving knowledge of the audience and of the health behavior change message. However, the influence of a source depends, in part, on the nature of the message per se. The “stronger” the message, the less important the source. Credible sources can increase the likelihood that a “weak” message will be accepted, but the credibility of the source has relatively little influence on the likelihood that an audience will accept a “strong” message (McCroskey, 1970).
The wide range of channels through which health communication messages are disseminated includes the mass media (television, radio, magazines, newspapers, and advertising); outdoor advertising; brochures, posters, and newsletters; comic books and fotonovellas; direct mail; interpersonal communications (such as in-person and telephone counseling); music and other videos;