Source Credibility

“The roots of the source credibility construct can be traced to Aristotle, a fourth century BC Greek philosopher. In his seminal work The Rhetoric Aristotle claims that ethos (i.e. the character of the speaker) “is the most potent of all the means to persuasion”.”

Stiff and Mongeau (2003, p104)

How people perceive the individual, or organisation, which is communicating with them, is likely to have a substantial impact on how their communications are perceived. Stiff and Mongeau (2003) argue that most writers on persuasion separate source credibility into two key characteristics source expertise and source trustworthiness. Source expertise (or competence) “is the extent to which an audience member perceives the source as being well informed on the topic of the communication… trustworthiness represents and audience member’s perceptions that the source will tell the truth as he or she knows it”

(Stiff and Mongeau, 2003, p105). Jowett and O’Donnell (1992) argue that once a source

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is ‘accepted’ in relation to one issue, that perceived credibility may carry over to other issues.

O’Keefe (1990) suggests that a number of factors may impact upon perceived

trustworthiness and competence. These include the education and occupation of the source. The citing of high quality evidence sources may also contribute to the source’s perceived credibility - O’Keefe suggests that the high credibility of cited sources may ‘rub off’ on the communicator. In addition, it is suggested that the position advocated by the source may also influence perceptions of their competence and trustworthiness. In particular, it is suggested that the source may be perceived as more competent and trustworthy where “the position advocated disconfirms the audience’s expectations about the communicator’s views” (O’Keefe, 1990, p136), O’Keefe suggests the classic example of this to be where their position appears opposed to their own self-interest.

Finally, evidence indicates that liking the communicator impacts upon their perceived trustworthiness, though not their credibility. O’Keefe (1990, p139) argues this makes common sense since:

“One’s general liking for a communicator is much more likely to influence one’s judgements about the communicator’s dispositional trustworthiness (the

communicator’s general honesty, fairness, open-mindedness, and the like) than it is to influence one’s judgments about the communicator’s competence

(experience, training, expertise and so on) on some particular topic or subject matter.”

Research indicates that the credibility of the source has a notable effect on the likelihood of immediate attitude change in their audience. One experiment by Hovland and Weiss (reported in Hovland, 1953, p27-30) presented students with articles on four different topics. To one set of students the articles were attributed to ‘high credibility sources’ and to the other set, they were attributed to ‘low credibility sources’. Although the articles from ‘high credibility’ and ‘low credibility’ sources were identical in content, “the

presentations were considered “less fair” and the conclusions to be “less justified” when the source was of low rather than of high credibility” (Hovland, 1953, p28). In addition,

“opinion change in the direction advocated by the communication occurred significantly

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more often when it originated from a high credibility source than when from a low one”

(Hovland, 1953, p29). However, it is notable that the experiment found that the differences between the groups of high and low credibility sources disappeared over time, with decreased acceptance of the point of view advocated by high credibility sources, and increased acceptance of the point of view advocated by low credibility sources. This may suggest that the impact of the credibility given to the source (in some cases) wears off faster than the influence of the content of the message (Hovland 1953, p30).

It may be hypothesised that campaign groups will attempt to present themselves as credible sources in order to maximise the persuasiveness of their communications. This issue is addressed in the analysis chapters, and is discussed in particular detail in chapter 8.

1.3.2. Evidence

It has already been argued that the citing of evidence may contribute to the perceived credibility of the communicator. However, it is clear that the use of evidence to support communications also intends to draw upon the ability of the audience to come to rational conclusions about an argument put to them. As Stiff and Mongeau (2003) put it:

“Persuasive messages that that contain rational arguments are based on the assumptions that people have implicit understanding of formal rules of logic and that they apply these rules when they make judgements about a source’s

recommendations. Rational arguments derive their influence from sound

reasoning and the quality of evidence that is offered in support of the conclusion.”

Stiff and Mongeau (2003, p129)

The idea that messages based on sound evidence are particularly persuasive is very intuitively acceptable, however, not all uses of evidence will have the same influence on an audience. Academic literature on persuasive communication emphasises two ‘routes’

to persuasion. The ‘central’ route to persuasion occurs when the audience “pays

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attention and carefully considers the arguments presented in the message” (Powers, 2007, p136). On the other hand, the ‘peripheral’ persuasive route occurs when the audience “only pays attention to superficial aspects of the message” (Powers, 2007).

Where the central persuasive route is taken, the ‘strength’ of the argument is of crucial importance, since they are given close consideration and scrutiny (Powers, 2007), where the argument is found to be “cogent and compelling” favourable attitudes will be created, where it is found to be “weak and specious” the message will be resisted (Petty and Cacioppo, 1984, p70) . In the case of peripheral persuasion, the strength of the argument is of little importance because the arguments themselves receive little consideration (Powers, 2007). Appeals to a central route to persuasion may therefore put emphasis on the provision of detailed evidence to support an argument.

A number of factors have been associated with the likelihood that an audience will

“receive and cognitively process a message” (Stiff and Mongeau, 2003, p131), i.e. engage in central processing.

One characteristic found to be associated with whether an audience engage with a message which they are presented with, is whether they are interested or involved in the issue (the ‘personal relevance’ to the receiver (O’Keefe, 1990)). “In short, the higher the audience’s involvement with the message topic, the more strongly evidence should influence attitude change.” (Stiff and Mongeau (2003, p132). Stiff (reported in Stiff and Mongeau 2003, p132) found that there was a positive correlation between the audience involvement in an issue, and the persuasiveness of evidence.

The audience’s “need for cognition”- their tendency to “engage in and enjoy thinking”

(Cacioppo and Petty, 1982, cited in O’Keefe, 1990, p100) - has also been identified as affecting the extent to which the receiver processes a communication. O’Keefe (1990, p101) concludes that people who tend to engage in and enjoy thinking “have generally greater motivation for engaging in issue-relevant thinking than do persons low in need for cognition.”

O’Keefe (1990, p102) also notes that prior knowledge about the issue on the part of the receiver, affects the likelihood that they will engage with the issue presented to them. As

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the receiver’s prior knowledge increases, the influence of the strength of the evidence on persuasion increases, and the influence of non-evidence based persuasion decreases.

This reflects the ability of people with greater knowledge about an issue to engage in counter arguments against the position advocated by the communicator (O’Keefe, 1990).

However, as well as being ‘cognitively processed’ further factors affect whether an evidence based message, once processed, actually brings about attitude change. In particular Stiff and Mongeau (2003, p133) highlight research which indicates that “when people agree with the conclusion of an argument they are more likely to judge invalid arguments that support the conclusion as valid, and to judge valid arguments against the conclusion to be invalid.”

Given that, at least in some circumstances, use of evidence can have a substantial impact upon the persuasiveness of communications, we might expect Third Sector Organisations able to provide strong and reliable evidence to support the policy changes they propose, to have a greater ability to input into the policy process than those who provide no evidence, or unreliable evidence, to support their views. As previously noted, Coe and Kingham (2007, p8) called “strong and compelling evidence” the “bedrock” of a

campaign.

Similarly, Whiteley and Winyard (1988) give further support to the importance of

evidence in anti poverty campaigning, with findings from their 1987 survey of anti poverty pressure groups;

“The single most widely held belief about effectiveness was that groups require accurate and detailed information about the needs of their clients and the impact of the social security system on them. This information was seen as a valuable resource in dealing with policy makers and in building a constructive long term relationship with officials. Some groups also recognized that good research could attract grant money from trusts, which play an important role in aiding fledgling groups.”

(Whiteley and Winyard, 1988, p205)

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It might be expected that extensive, high-quality evidence, will be particularly important in insider campaigning for two key reasons. Firstly, the topics addressed will have high personal relevance for the policymakers (since they are directly involved in them). And secondly, the policymakers will have prior knowledge of the policy area. Both of these factors have been associated with the importance of evidence. The use of evidence in Third Sector communications to policymakers is discussed in chapter 8.