Understanding the effect of advertising -- whether positive or negative -- on its audience is the focal point of persuasion theory. Early interest in building a body of knowledge about persuasion theory can be traced to Yale University and psychologist Carl I. Hovland, who conducted studies there during the 1940s and '50s. Mr. Hovland was credited with undertaking the first systematic research projects on learning and attitude change. He and his peers, Icek Ajzen, Martin Fishbein, Milton Rosenberg and Wilbur Schramm, are credited with creating the discipline of persuasion theory.
Mr. Hovland's "Message Learning Theory" posits that the more people learn and remember from an ad, the more persuasive the ad will be. His research was designed around the step-by-step process through which people are persuaded: attention, comprehension, yielding and retention of the message.
Practical guidelines suggested by message learning theory include, for example, that repetition of a message increases learning; commercials "wear out" faster among serious TV users; and commercials that employ brand users as the message source wear out more slowly than do those that use only straightforward claims and basic support.
"Source characteristics" themselves were another major research track within message learning theory, and Mr. Hovland and his colleagues argued that the source of the message had a huge persuasive impact on audiences. They believed that audiences evaluate a source using two independent characteristics -- the degree to which the speaker is perceived to be an expert on the topic and the degree to which the speaker is perceived to be trustworthy.
Message learning theorists also investigated characteristics inherent in the receivers of messages, seeking to determine if certain audience segments -- once separated from the general population on the basis of personality traits or demographic characteristics -- are more readily persuaded by advertising than other groups.
Finally, research into the characteristics of communication channels -- TV, radio, newspapers, magazines and billboards, among others -- suggested that, for example, radio was a poor choice for an advertiser seeking to convey a message that is difficult to comprehend.
In contrast, in self-persuasion theory, the degree of persuasion is linked to the way receivers become involved with and react to the message. Those following this school of thought contend that receivers become involved with an ad and elaborate on the message. They take an active role in establishing the advertisement's meaning and persuading themselves to bolster, accept, distort, derogate or reject the advice contained in the message.
The elaboration-likelihood model proposed by Richard E. Petty and John T. Cacioppo in 1986 is an example of self-persuasion theory. It posits three forces that cause receivers to elaborate in one of two ways when processing an ad. Here the term "elaboration" implies issue-relevant thinking about such aspects of the ad as its topics, arguments, implications, consequences, promises and executional elements.
The three forces are motivation (i.e., the need for information about brand-based benefits), the ability or expertise to grasp the arguments and the opportunity to process benefit-based claims. The two routes that receivers can elaborate on are the central and the peripheral routes.
If receivers have the motivation, ability and opportunity to process information, they will follow the central route in processing the information, elaborating rationally on such direct benefit-based claims as gas mileage or trunk space when dealing with the purchase of a car, for example. Conversely, receivers will elaborate on peripheral cues (e.g., the setting, originality, humor and feelings conveyed) in an ad when they lack the motivation, ability and opportunity to judge rational, benefit-based appeals.
This model highlights the central premise of self-persuasion theory; persuasion depends on the involvement that receivers attach to the message.
Persuasion theory has borrowed much of its foundation from other academic fields, especially the behavioral sciences. Three widely used learning theories taken from the behavioral sciences are classical conditioning, instrumental learning and social learning theory. Common to these theories is the view that learning is a process by which human behavior is acquired or changed through events in one's environment. Moreover, an explicable or predictable relationship exists between stimuli and responses. Learning theory produced several implications for advertising strategists:
- Individuals differ in their ability, readiness and motivation to deal with a persuasive message.
- Reinforcement is helpful in establishing response.
- Active participation is better than passive participation.
- Meaningful responses to messages are learned more easily than meaningless ones.
Advertisers have also benefited from insights unearthed by attribution theory and the theory of reasoned action. Attribution theory underscores the importance of causal inference, or a person's "perception of why things occur"; the chain of events and consequences are important.
Causal meaning is essential in advertising for several reasons. Source credibility is strongly influenced by the type of causal inference receivers make concerning why the speaker is advocating a particular position. Causal attribution strives to explain why and how people make inferences about their own attitudes and reasons for their behavior. The types of causes that receivers see underlying events have a significant impact on how customers react to a company.
Attribution theory was used to better understand the effectiveness of positive and negative claims in advertising. Research has shown that the believability of some product claims and the credibility of a message are increased by disclaiming superiority across brand attributes, especially when disclaiming superiority on criteria of little importance to buyers.
In a different vein, attitude theory was applied to advertising because experts originally believed that attitudes precede and influence purchase. Attitude theorists sought to uncover directives on the best ways to create, shape and reinforce attitudes, believing that if positive attitudes could be created, actions desired by advertisers likely would follow.
The theory of reasoned action contends that behavior is rational and rarely caused by only one or two beliefs. This theory views attitude, defined as a predisposition to respond either positively or negatively to an object, as an overall factor that includes multiple beliefs about several salient and deterministic attributes. In contrast to the feelings-based behavior noted in the elaboration-likelihood model, reasoned action posits that an intention to behave is purposeful, goal-oriented and unaffected by feelings and emotions. Choice is reasoned and based on sound judgment; it may be influenced by one's intention to comply with the norms of others.
Attitude research findings, when combined with the directives uncovered from research into information processing, provide advertisers with food for thought as they create their messages. Because not all attributes are equally important to an audience, advertisers are urged to emphasize salient benefits of their products or services.
Audiences will often reject objects that fail to offer salient attributes, although these attributes are not always strong enough to cause choice. Choice, instead, tends to depend on the evaluation of deterministic attributes since they are most highly sought by the audience.