Messages delivered by attractive or popular sources achieve higher attention and recall. Advertisers often use celebrities as spokespersons, but what matters here is the credibility of the spokesperson. Messages delivered by highly credible sources are more persuasive.
EX: Pharmaceutical person selects doctors to testify that his product has benefits because doctors have high credibility. Anti drug campaigner will use ex-drug addict to warn school children about drugs, because they are more influential than teachers.
Credibility depends on three factors- expertise, trustworthiness and likability.
Expertise is the specialized knowledge the communicator possesses to back the claim. Doctors, Professors and Scientists rank high on expertise.
Trustworthiness is related to how objective and honest the source is perceived to be. Friends are trusted more than strangers or sales persons and people who are not paid to endorse a product are often considered more trustworthy than persons who are paid.
Likability is the source’s attractiveness to the audience. Frankness, humor and naturalness make a source more likable. The most highly credible source is the person who scores high on all the three dimensions.
