Persuasion header image
The Nature of Attitudes and Persuasion

The Yale Approach

Congruity Theory

Cognitive Dissonance Theory

Social Judgment/ Involvement Theory

Information Integration Theory

Theory of Reasoned Action

Elaboration Likelihood Model


The Yale Approach
The Yale Approach - Overview 
- Message Organization
- Message Content
Strengths and Weaknesses of the Yale Approach

Messages can be divided into two basic parts: organization and content. This section will discuss message content.

Message Content

Three important areas of investigation into the content of persuasive messages are message arguments (quality and quantity of arguments), evidence, and fear appeals. I will discuss each area separately in this section.

Research demonstrates that argument strength is directly related to attitude change (
Andrews & Shimp, 1990; Cacioppo, Petty, & Morris, 1983; Petty, Cacioppo, & Goldman, 1981). This means the stronger the argument, the more the attitude change it creates -- and the weaker the argument, the less attitude change it creates. It makes sense that arguments that are stronger, or higher quality, would be more persuasive than arguments that are weaker, or poorer quality. Messages with more arguments are more persuasive than those with fewer arguments (Calder, Insko, & Yandell, 1974; Chaiken, 1980; Cook, 1969; Petty & Cacioppo, 1984). The more arguments in a message, the more likely it will seem to be true (or the more likely that a message will include at least one argument that appeals to the audience). These factors probably influence persuasion by aiding yielding -- we are more likely to accept arguments that are stronger.

Some messages try to persuade people through the use of fear appeals: “You shouldn’t smoke because cigarettes can cause lung cancer and heart disease and kill you.”  Research on fear appeals reveals a direct relationship between fear appeals and persuasion: the greater the fear appeal, the more persuasion will occur (
Mongeau, 1998). However, there are four key elements to an effective fear appeal (Roger , 1983). First, the threat in the fear appeal must be serious. Smokers must believe that cigarettes really can damage their health. Second, the audience must believe that the problem identified in the fear appeal could strike them. Some smokers know that not every smoker dies from lung cancer or heart disease (my grandfather smoked until he was 94, and then he died from a car wreck, not from cigarettes). They may believe that smoking might hurt some people, but not them. Third, the messages should offer a means of coping with the threat (a solution) that appears effective to the audience. If a smoker doesn’t believe he or she can really quit (believing that the nicotine in cigarettes is too addictive), the fear appeal won’t cause persuasion. Finally, the audience must believe that they have the power or ability to implement the solution. If there is an effective treatment for smoking but it is too expensive, the fear appeal will fail. Fear appeals may improve attention (I want to listen so I can avoid this threat) and yielding (I will agree so I can avoid or lessen the threat).

Evidence comes in many varieties: examples, statistics, and expert testimony are common forms (sometimes persuaders use physical evidence, as we see in televised trials). Expert testimony refers to statements of fact that the speaker attributes to someone else (an expert). For example, if a speaker quotes a professor of criminology in a speech on crime, that is an instance of expert testimony. Research has demonstrated that evidence has a consistent and strong effect on persuasion (
Reinard, 1998). Research suggests that evidence is also effective at creating resistance to persuasion -- in protecting those who agree with you from attempts by others to change their attitudes (McCroskey, 1970). A few studies have compared examples with statistics. Generally, evidence from examples is more persuasive (Taylor & Thompson, 1982). Examples also create resistance to counter persuasion (Bridges & Reinard (1974). Evidence might increase attention and comprehension (and examples seem particularly useful in increasing understanding). Evidence also probably has important effects on yielding.

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