The initial opinion of audience members appears to be one important influence on the impact of source credibility. Specifically when receivers already hold opinions that are opposite to those presented in a message, a highly credible source is likely to generate more attitude change than will sources of lower credibility. However, when audience pinions already favor positions to be presented in message than highly credible source have not been found more effective than sources of lower credibility in generating attitude change. In fact some research even suggests that sources of lower credibility will actually be more effective in generating attitude change.
To appreciate why these statements may have validity we must understand that communications can generate cognitive responses among consumers. Recall from the section on memory that cognitive response refers to thoughts a consumer will retrieve from long term memory upon exposure to a communication such as an advertising message. Those responses most relevant tour discussions here are (1) counterarguments – thoughts stored in long term memory that are used to contradict aspects of the message being received and (2) support arguments – thoughts stored in long term memory that re used to support aspects of the received message. Counter arguments are generated by receivers when messages oppose their initial opinions, and support arguments are developed for messages consistent with initial positions. One interesting finding is that highly credible sources appear to have such significant believability that they tend to block cognitive responses. This means that when receivers are initially opposed to information in a message highly credible sources will tend to block counterarguments. The message is therefore likely to be accepted without much modification yielding considerable change in attitudes. However, the same message received from sources having lower credibility will be critically renewed. This will generate counterarguments tending to neutralize points made in the message. Therefore the amount of attitude change will be less than what a highly credible source could achieve.
What happens when receiver initial opinions or beliefs are consistent with the content of message? The message transmitted from a highly credible source will again be accepted without much critical examination. However, because it is consistent with the receiver’s existing position, a large amount of attitude cage is unlikely. Conversely, as before the same message received from a less credible source will be critically reviewed and will generate cognitive responses. Because the cognitive responses will now be in the form of support arguments, the resulting attitude change can be greater than that achieved by the highly credible source.
Important practical implications can be drawn from this analysis. First, marketers may usually want to avoid developing communications that oppose consumers’ opinions because of their requirements for a highly credible source. Since the task of achieving very high credibility in a marketing context is quite difficult, often expensive and sometimes impossible an alternate to consider carefully is using communications consistent with consumers’ positions. However, when fighting rumors had publicity various other forms of unwarranted consumer beliefs the design of such opposing communications may be necessary. In these cases, it would be quite important to carefully identify ad use sources that will have high credibility for the specific situation at hand.
Message discrepancy conditions
A topic closely related to the above discussion is message discrepancy. Highly discrepant messages do not completely oppose receivers initial opinions, but are quite deviant from the receivers’ beliefs. Marketers encounter such situations when they wish to demonstrate extraordinary products such as Super Clue or to make claims about their offerings that differ considerably from current beliefs in the target market. Similar to how situation of negative initial opinions very credible sources are most effective in achieving attitude change fir highly discrepant messages. As before the explanation appears to be that high credibility minimizes cognitive responses, which are likely to be counterarguments in cases of high discrepancy. For messages of little discrepancy, counterarguments are less likely while support arguments will be more prevalent. Therefore under such conditions les credible sources can be effective in achieving attitude change.