There are many theories of persuasion in communication studies. Three of the main theories that are often associated with persuasion are the social judgment theory, cognitive dissonance theory, and the elaboration likelihood model.

Social Judgment Theory

Muzafer Sherif and Carl Hovland created social judgment theory in an attempt to determine what types of communicative messages and under what conditions communicated messages will lead to a change in someone’s behavior (Sherif & Hovland, 1961). In essence, Sherif and Hovland found that people’s perceptions of attitudes, values, beliefs, and behaviors exist on a continuum including latitude of rejection, latitude of noncommitment, and latitude of acceptance.

Latitudes of Judgments

Imagine that you are planning to persuade your peers to major in a foreign language in college. Some of the students in your class may disagree with you right off the bat, representing the latitude of rejection. Other students may think majoring in a foreign language is a great idea, representing the latitude of acceptance. Still others are really going to have no opinion either way, representing the latitude of noncommitment. Within each of these different latitudes there is a range of possibilities. For example, one of your listeners may be perfectly willing to accept the idea of minoring in a foreign language, but when asked to major or even double major in a foreign language, he or she may end up in the latitude of noncommitment or even rejection.

Not surprisingly, Sherif and Hovland found that persuasive messages are the most likely to succeed when they fall into an individual’s latitude of acceptance. For example, if you are giving your speech on majoring in a foreign language, people who are in favor of majoring in a foreign language are more likely to positively evaluate your message, assimilate your advice into their own ideas, and engage in desired behavior. On the other hand, people who reject your message are more likely to negatively evaluate your message, not assimilate your advice, and not engage in desired behavior.

In an ideal world, we would always be persuading people who agree with our opinions, but that is not reality. Instead, we often find ourselves in situations where we are trying to persuade others to accept attitudes, values, beliefs, and behaviors with which they may not agree. To help us persuade others, what we need to think about is the range of possible attitudes, values, beliefs, and behaviors that exist. For example, in our foreign language case, we may see the following possible opinions from our audience members:

1. Complete agreement. All of us should major in foreign languages.
2. Strong agreement. I will not major in a foreign language, but I will double major in a foreign language.
3. Agreement in part. I will not major in a foreign language, but I will minor in a foreign language.
4. Neutral. While I think studying a foreign language can be worthwhile, I also think a college education can be complete without it. I really do not feel strongly one way or the other.
5. Disagreement in part. I will only take the foreign language classes required by my major.
6. Strong disagreement. I do not think I should have to take any foreign language classes.
7. Complete disagreement. Majoring in a foreign language is a complete waste of a college education.

These seven possible opinions on the subject do not represent the full spectrum of choices, but give us various degrees of agreement with the general topic. Sherif and Hovland theorized that persuasion is a matter of knowing how great the discrepancy or difference is between the speaker’s viewpoint and that of the audience. If the speaker’s point of view is similar to that of audience members, then persuasion is more likely. If the discrepancy between the idea proposed by the speaker and the audience’s viewpoint is too great, then the likelihood of persuasion decreases dramatically.

Discrepancy and Attitude Change

Furthermore, Sherif and Hovland (1961) predicted that there was a threshold for most people where attitude change was not possible and people slipped from the latitude of acceptance into the latitude of noncommitment or rejection. Figure 17.2 “Discrepancy and Attitude Change” represents this process. All the area covered by the left side of the curve represents options a person would agree with, even if there is an initial discrepancy between the speaker and audience member at the start of the speech. However, there comes a point where the discrepancy between the speaker and audience member becomes too large, which moves into the options that will be automatically rejected by the audience member. In essence, it becomes essential for you to know which options you can realistically persuade your audience to and which options will never happen. Maybe there is no way for you to persuade your audience to major or double major in a foreign language, but perhaps you can get them to minor in a foreign language.

Cognitive Dissonance Theory

In 1957, Leon Festinger proposed another theory for understanding how persuasion functions: cognitive dissonance theory (Festinger, 1957). Cognitive dissonance is an aversive motivational state that occurs when an individual entertains two or more contradictory attitudes, values, beliefs, or behaviors simultaneously. For example, maybe you know you should be working on your speech, but you really want to go to a movie with a friend. In this case, practicing your speech and going to the movie are two cognitions that are inconsistent with one another. The goal of persuasion is to induce enough dissonance in listeners that they will change their attitudes, values, beliefs, or behaviors.

Frymier and Nadler (2007) noted that for cognitive dissonance to work effectively there are three necessary conditions: aversive consequences, freedom of choice, and insufficient external justification. First, for cognitive dissonance to work, there needs to be a strong enough aversive consequence, or punishment, for not changing one’s attitudes, values, beliefs, or behaviors. For example, maybe you are giving a speech on why people need to eat more apples. If your aversive consequence for not eating apples is that your audience will not get enough fiber, most people will simply not be persuaded, because the punishment is not severe enough. Instead, for cognitive dissonance to work, the punishment associated with not eating apples needs to be significant enough to change behaviors. If you convince your audience that without enough fiber in their diets they are at higher risk for heart disease or colon cancer, they might fear the aversive consequences enough to change their behavior.

The second condition necessary for cognitive dissonance to work is that people must have a freedom of choice. If listeners feel they are being coerced into doing something, then dissonance will not be aroused. They may alter their behavior in the short term, but as soon as the coercion is gone, the original behavior will reemerge. It is like the person who drives more slowly when a police officer is nearby but ignores speed limits once officers are no longer present. As a speaker, if you want to increase cognitive dissonance, you need to make sure that your audience does not feel coerced or manipulated, but rather that they can clearly see that they have a choice of whether to be persuaded.

The final condition necessary for cognitive dissonance to work has to do with external and internal justifications. External justification refers to the process of identifying reasons outside of one’s own control to support one’s behaviors, beliefs, and attitudes. Internal justification occurs when someone voluntarily changes a behavior, belief, or attitude to reduce cognitive dissonance. When it comes to creating change through persuasion, external justifications are less likely to result in change than internal justifications (Festinger & Carlsmith, 1959).

Elaboration Likelihood Model

The elaboration likelihood model created by Petty and Cacioppo (1986) has a continuum from high elaboration or thought to low elaboration or thought. For the purposes of Petty and Cacioppo’s model, the term elaboration refers to the amount of thought or cognitive energy someone uses for analyzing the content of a message. High elaboration uses the central route and is designed for analyzing the content of a message. As such, when people truly analyze a message, they use cognitive energy to examine the arguments set forth within the message. In an ideal world, everyone would process information through this central route and actually analyze arguments presented to them. Unfortunately, many people often use the peripheral route for attending to persuasive messages, which results in low elaboration or thought. Low elaboration occurs when people attend to messages but do not analyze the message or use cognitive energy to ascertain the arguments set forth in a message.

For researchers of persuasion, the question then becomes: how do people select one route or the other when attending to persuasive messages? Petty and Cacioppo noted that there are two basic factors for determining whether someone centrally processes a persuasive message: ability and motivation. First, audience members must be able to process the persuasive message. If the language or message is too complicated, then people will not highly elaborate on it because they will not understand the persuasive message. Motivation, on the other hand, refers to whether the audience member chooses to elaborate on the message. Frymier and Nadler discussed five basic factors that can lead to high elaboration: personal relevance and personal involvement, accountability, personal responsibility, incongruent information, and need for cognition (Frymier & Nadler, 2007).

Personal Relevance and Personal Involvement

The first reason people are motivated to take the central route or use high elaboration when listening to a persuasive message involves personal relevance and involvement. Personal relevance refers to whether the audience member feels that he or she is actually directly affected by the speech topic. For example, if someone is listening to a speech on why cigarette smoking is harmful, and that listener has never smoked cigarettes, he or she may think the speech topic simply is not relevant. Obviously, as a speaker you should always think about how your topic is relevant to your listeners and make sure to drive this home throughout your speech. Personal involvement, on the other hand, asks whether the individual is actively engaged with the issue at hand: sends letters of support, gives speeches on the topic, has a bumper sticker, and so forth. If an audience member is an advocate who is constantly denouncing tobacco companies for the harm they do to society, then he or she would be highly involved (i.e., would engage in high elaboration) in a speech that attempts to persuade listeners that smoking is harmful.

Accountability

The second condition under which people are likely to process information using the central route is when they feel that they will be held accountable for the information after the fact. With accountability, there is the perception that someone, or a group of people, will be watching to see if the receiver remembers the information later on. We have all witnessed this phenomenon when one student asks the question “will this be on the test?” If the teacher says “no,” you can almost immediately see the glazed eyes in the classroom as students tune out the information. As a speaker, it is often hard to hold your audience accountable for the information given within a speech.

Personal Responsibility

When people feel that they are going to be held responsible, without a clear external accounting, for the evaluation of a message or the outcome of a message, they are more likely to critically think through the message using the central route. For example, maybe you are asked to evaluate fellow students in your public speaking class. Research has shown that if only one or two students are asked to evaluate any one speaker at a time, the quality of the evaluations for that speaker will be better than if everyone in the class is asked to evaluate every speaker. When people feel that their evaluation is important, they take more responsibility and, therefore, are more critical of the message delivered.

Incongruent Information

Some people are motivated to centrally process information when it does not adhere to their own ideas. Maybe you are a highly progressive liberal, and one of your peers delivers a speech on the importance of the Tea Party movement in American politics. The information presented during the speech will most likely be in direct contrast to your personal ideology, which causes incongruence because the Tea Party ideology is opposed to a progressive liberal ideology. As such, you are more likely to pay attention to the speech, specifically looking for flaws in the speaker’s argument.

Need for Cognition

The final reason some people centrally process information is because they have a personality characteristic called need for cognition. Need for cognition refers to a personality trait characterized by an internal drive or need to engage in critical thinking and information processing. People who are high in need for cognition simply enjoy thinking about complex ideas and issues. Even if the idea or issue being presented has no personal relevance, high need for cognition people are more likely to process information using the central route.

References

Festinger, L. (1957). A theory of cognitive dissonance. Row, Peterson, & Company.

Festinger, L., & Carlsmith, J. M. (1959). Cognitive consequences of forced compliance. Journal of Abnormal and Social Psychology, 58, 203–210.

Frymier, A. B., & Nadler, M. K. (2007). Persuasion: Integrating theory, research, and practice. Kendall/Hunt.

Petty, R. E., & Cacioppo, J. T. (1986). The elaboration likelihood model of persuasion. Advances in Experimental Social Psychology, 19, 123–205.

Sherif, M., & Hovland, C. I. (1961). Social judgment: Assimilation and contrast effects in communication and attitude change. Yale University Press.