Persuasive Communication Theory

Persuasive Communication Theory in Social Psychology: A Historical Perspective Icek Ajzen University of Massachusetts – Amherst From M. J. Manfredo (Ed) (1992). Influencing Human Behavior: Theory and Applications in Recreation and Tourism (pp 1– 27). Champaign, IL: Sagamore Publishing. Persuasive Communication Theory Page 1 Few subjects in social psychology have attracted as much interest and attention as persuasive communication. One of the first topics to be systematically investigated, persuasion has been the focus of intense research efforts throughout much of social psychology's brief scientific history.Untold experiments have been conducted to unravel the intricate web of factors that appear to play a role in determining the effectiveness of a persuasive message. These attempts have revealed a degree of complexity that seems to defy explanation and that poses serious obstacles to theory construction. However, recent years have seen considerable progress at the the oretical level and a resurgence of empirical work has done much to invigorate the field and provide a better understanding of the fundamental psychological processes underlying persuasion.To appreciate the significance of these developments we must compare the emerging ideas and research findings with those from earlier efforts. The present chapter is designed to provide the required historical perspective. Since it aims to review developments in our understanding of the persuasion process, emphasis is placed on ideas and theories rather than on methodological or practical concerns; empirical research findings are summarized only in broad outline when needed to make a point of theoretical significance.The solution of problems created by recreation and tourism often involves persuasion in one form or another. As the chapters in the second part of this book illustrate, recreationists must be persuaded to observe rules of safety, to avoid conflicts with other visitors, and to keep thei r impact on the environment to a minimum. Although social psychologists have rarely tested their ideas in the context of recreation and tourism, the findings and conclusions discussed below have obvious implications for any attempt to influence beliefs, attitudes, and behavior in this domain.THE NATURE OF PERSUASION Persuasive communication involves the use of verbal messages to influence attitudes and behavior. Although the context of persuasion must necessarily be considered, the verbal message, designed to sway the hearts and minds of the receivers, is at the core of persuasive communication. Through a process of reasoning, the message exerts its influence by force of the arguments it contains. As we shall see below, this emphasis on reasoning sets persuasive communication apart from other social influence strategies.Structure of a Message As a general rule, a message consists of three parts: An advocated position, a set of general arguments in support of the advocated position, and specific factual evidence designed to bolster the general arguments (Fishbein and Ajzen, 1981). The advocated position may be a stand on a particular issue (e. g. , support for a tax increase) or a recommended action (e. g. , donating blood). The general arguments will typically supply reasons for adopting the advocated position, and justification for the arguments is provided in the form of factual evidence.Consider the question of instituting a senior comprehensive examination for undergraduate college students. Petty and Cacioppo (1986, pp. 54-59) published some examples of general arguments and supportive evidence they have used in their research program. Among the major arguments contained in Petty and Cacioppo's messages were the claims that instituting a comprehensive exam raises students' grade point averages and leads to improvement in the quality of undergraduate teaching. The factual evidence in support of the first argument was formulated as follows (pp. 4-55): The N ational Scholarship Achievement Board recently revealed the results of a five-year study conducted on the effectiveness of comprehensive exams at Duke University. The results of the study showed that since the comprehensive exam has been introduced at Duke, the grade point average of undergraduates has increased by 31%. At comparable schools without the exams, grades increased by only 8% over the same period. The prospect of a comprehensive exam clearly seems to be effective in challenging students to work harder and faculty to teach more effectively.It is likely that the benefits observed at Duke University could also Persuasive Communication Theory Page 2 be observed at other universities that adopt the exam policy. If accepted as valid, the factual evidence should result in acceptance of the argument that instituting a senior comprehensive exam will raise grade point averages, and acceptance of the argument in turn should increase the likelihood that receivers will endorse the po sition in favor of instituting a comprehensive exam, as advocated in the message.There is, of course, no assurance that receivers of a message will in fact accept the arguments and evidence it contains. On the contrary, identifying the factors and conditions that produce acceptance of information contained in a message is the major purpose of persuasion theory and research. Alternative Influence Strategies In order to develop a better understanding of the nature of persuasion, it is instructive to contrast persuasion with a few alternative influence strategies. The review offered here is far from exhaustive but it will help highlight some critical aspects of persuasive communication.Coercive Persuasion People can be induced to behave in a prescribed way by offering a sizable reward for compliance or by threatening severe punishment for noncompliance. This strategy of change can be very effective in producing the desired behavior, but its effectiveness is contingent on supervision (F rench and Raven, 1959) and has few lasting effects on beliefs or attitudes. Enduring attitude change by means of coercion is more likely in the context of total institutions, such as prisons, mental hospitals, or prisoner-of-war camps.Situations of this kind enable control over many aspects of an individual's life for an extended period of time. Even here, however, enduring attitude change is difficult to obtain and often fades after release from the institution (see Schein, 1961). Hypnosis and Subliminal Perception Instead of trying to overcome resistance to change by force of coercion, one can attempt to circumvent conscious opposition by means of hypnosis or presentation of subliminal messages. Posthypnotic induction can be used to instruct individuals upon awakening to engage in specified behaviors or to hold new attitudes (e. . , Rosenberg, 1956). There is, however, some question as to whether hypnosis actually represents an altered state of consciousness that can be used to ci rcumvent people's usual resistance to manipulation of their beliefs and actions (cf. Barber, 1965; Wagstaff, 1981). Use of subliminal perception to bring about change is similarly problematic. Its effectiveness depends on the presentation of information at an intensity level too low for conscious perception, yet high enough for it to enter unconscious or subconscious awareness.Clearly, such a fine balance demands careful calibration and, given individual differences in perceptual acuity, may not be achievable in a mass communication context. In any event, even when subliminal perception can be demonstrated, its effects on attitudes and behavior tend to be of rather small magnitude (cf. Erdelyi, 1974). Conditioning and Affect Transfer Another way of trying to avoid resistance to change involves the use of conditioning procedures. It has been argued that attitudes can be changed by means of classical conditioning (e. . , Staats and Staats, 1958) and that behavior can be influenced thr ough the systematic use of reinforcements in an instrumental conditional paradigm (e. g. , Krasner, 1958). Since the advantage of conditioning in comparison to direct persuasion rests on the assumed ability of conditioning to operate without awareness of the influence attempt, the extent to which individuals submitted to conditioning form hypotheses about systematic associations created in the conditioning paradigm is of crucial importance.Contrary to earlier claims, it now appears that there is no convincing evidence that adult human beings can be conditioned without awareness (cf. Brewer, 1974). An idea related to classical conditioning has emerged in the recent marketing literature where it has been proposed (Batra and Ray, 1986; Mitchell and Olson, 1981) that positive or negative affect elicited by one stimulus (the advertising) can transfer automatically to an associated stimulus (the advertised brand). This Persuasive Communication Theory Page 3 ffect transfer, however, is ass umed to occur only when individuals have no other, more informed basis, for evaluating the brand in question (Shimp, 1981). Moreover, given the results of research on conditioning in human beings, it can be assumed that affect transfer, if it occurs at all, occurs only in the presence of awareness of the contingencies involved. Subterfuge obvious heuristic in a persuasion context has to do with the communicator's credibility. The position advocated in a message may be accepted if the message comes from a highly credible source but rejected if the source is perceived to lack credibility.When using this rule of thumb, receivers accept or reject the advocated position or action without considering the merits of the arguments contained in the message. Conclusions Whereas the strategies discussed thus far all in one way or another try to prevent or neutralize awareness of, and thus resistance to, the influence attempt, the strategies considered here subtly manipulate the situation in ord er to promote a psychological state that leads people voluntarily to engage in the desired behavior.The foot-in-the-door technique (Freedman and Fraser, 1966) and other sales ploys are good examples of this approach. When using the footin-the-door technique, a small request SQ acceded to by most individuals SQ is followed by a much larger request. Due presumably to the commitment produced by agreeing to the small request, conformity with the large request tends to increase. An alternative strategy involves first confronting a person with an unreasonably large request and then appearing to compromise by offering compliance with a smaller request.In a highly readable book, Cialdini (1988) describes a number of ways in which subterfuge of this kind can be employed to elicit behaviors that might otherwise not be performed. Subterfuge strategies take advantage of people's various needs to reciprocate any favor received, to be liked by others, to be consistent, and so forth. Compliance is secured without the benefit of discussing the merits or costs of the requested action. Heuristics We have noted that change by means of persuasive communication is based on a careful deliberation of the pros and cons associated with an advocated position or ction. We shall see in subsequent sections, however, that receivers of a message sometimes make judgments about the advocated position without going through an elaborate reasoning process. Instead, they may rely on heuristics or rules of thumb to arrive at a conclusion (cf. Chaiken, 1980, 1987). The most Our discussion shows that social influence can operate in a variety of ways and that various strategies are available to take advantage of the different possibilities. Nevertheless, persuasive communication occupies a unique position in the matrix of social influence.Of all the available strategies it is the only one that appeals to reason, attempting to bring about change and compliance by convincing the individual of the valid ity or legitimacy of the advocated position. This tactic can be much more difficult than, say, coercion, but it also has important advantages. Besides being more compatible with democratic and humanistic values, persuasive communication can produce profound and lasting change, a goal not easily attained by other means. THE PERSUASION CONTEXT No message appears in a vacuum.At a minimum, we can usually identify the source of a message: an editor of a newspaper editorial, a lawyer pleading a client's case before a jury, or a movie star asking for donations to a charity. The communicator's identity, however, is only one of the many factors that constitute the context of persuasive communication. Classical analysis (Lasswell, 1948) has divided communication into several distinct aspects that can be summarized as who says what, how, and to whom. More formally these aspects are known as source, message, channel, and receiver factors; together, they constitute the context of 1 persuasion.So urce Factors Source factors are observed or inferred characteristics of the communicator. They include biological attributes such as age, race, height, and sex; behavioral features such as Persuasive Communication Theory Page 4 facial expressions, mannerisms, hand and body movements, and the way the communicator is dressed; social properties such as income, power, and social status; and personality traits such as self-confidence and extraversion. The most frequently studied source factors, however, are the communicator's credibility and attractiveness.Credibility refers to the perceived expertise and trustworthiness of the communicator. In other words, does the communicator have the knowledge to provide an informed opinion on the issue in question and, if so, can he or she be trusted to present all relevant information in an unbiased fashion? As noted earlier, persuasion is generally assumed to increase with credibility. It has similarly been proposed that the amount of change is in fluenced by the attractiveness or likability of the source, whether attractiveness is defined in terms of physical features or psychological and behavioral characteristics.Receiver Factors On the opposite end of the communication context, parallel to source factors, are characteristics of the receiver or audience to whom the message is addressed. These characteristics include the receivers' personality traits, sex, social status, intelligence, involvement, and so forth. Any attribute of the audience, or combination of attributes, may provide a context that contributes to the effectiveness of the message. Channel Factors The context of the message is also defined by the means used to communicate it.Information can be communicated face-to-face, in writing, or by way of an audio tape or video tape. Note that although it is possible to hold the content of the message (the general arguments and factual evidence) constant across channels, different modes of communication will often vary i n terms of some of the context factors. For instance, the audience obtains more information about physical and behavioral characteristics of the source from face-to-face or video messages than when the information is presented in written or oral form.Thus, it may be difficult in some instances to determine whether differences in persuasion are due to variations in the communication channel or to associated contextual differences that may confound the observed effect. Message Factors Potential confounding of a more serious kind can occur in the case of message factors because variations message features are often accompanied by differences in content. Message factors concern the ways in which information is communicated to the audience.Among the factors that have been considered are the order in which arguments are presented, one- versus twosided presentations, and emotional versus nonemotional appeals (e. g. , humorous messages or messages that arouse fear versus neutral messages). To see why variations in message characteristics are often confounded with differences in message content, consider the case of one- versus two-sided communications. Clearly, to present both sides of an issue, an effective message must contain information and arguments not contained in a message that supports only the advocated position.In a twosided message, the communicator mentions arguments that could be used to support the opposite side and then proceeds to refute those arguments. In addition, of course, the communicator also discusses the arguments in favor of the position advocated in the message. Only this part is the same as or similar to the one-sided message. In the case of emotional versus neutral appeals, problems of confounding occur because humorous or fear-arousing communications generally contain information and arguments specifically designed to generate these emotions.It is thus difficult to separate the effects of fear or humor from the effects due to differences in the information contained in humorous versus nonhumorous messages or in high- versus lowfear messages. Situational Factors The persuasion context contains several situational variables that do not fit easily into the traditional framework of source, message, channel, and receiver factors. Among these situational variables are distraction and forewarning. Distraction can be the result of environmental noise, or it can be internal as when a person is preoccupied with other concerns.Forewarning refers to the availability Persuasive Communication Theory Page 5 of information before exposure to the message, which warns the receiver either that an influence attempt is imminent or that the communicator is planning to advocate a certain position. In either case, forewarning may prepare receivers to rally their defenses against the forthcoming message. The Hovland Tradition Scientific work on persuasive communication began in earnest during World War II in an attempt to determine the eff ects of war-time propaganda (Hovland, Lumsdaine, and Sheffield, 1949).This was followed by a period of intensive experimental research at Yale University in the 1950s under the direction of Carl Hovland (Hovland, Janis, and Kelley, 1953; Sherif and Hovland, 1961). Although it was extremely prolific and highly influential, the program of research initiated by the Hovland group produced very few generalizable conclusions. By the late 1960s, disappointment with this approach had become widespread (see Eagly and Himmelfarb, 1974; Fishbein and Ajzen, 1975). In this section we review the major lines of work in the Hovland tradition and consider some of the reasons for its failure.Theoretical Orientation The empirical work of the Hovland group was guided by a loose theoretical analysis based on learning principles, and by a conceptual framework that incorporated context variables (source, message, channel, and receiver factors), target variables (immediate attitude change, retention, behav ior change), and mediating processes (attention, comprehension, and acceptance) (see McGuire, 1969, 1985). Very briefly, the theoretical analysis assumed that attitude change involves learning a new response to a given stimulus (the attitude object).Exposure to a persuasive message suggests the new response (the advocated position) and provides an opportunity to practice the response. The various contextual factors were assumed to facilitate learning by reinforcing and firmly embedding the new response in the receiver's response hierarchy. Empirical Research The conceptual framework of context, target, and mediating variables served to organize thinking about the persuasion process. However, much of the empirical research in the Hovland tradition dealt primarily with the impact of contextual factors.Thus, in the 1950s and 1960s, hundreds of studies were conducted to examine the effects of source credibility and attractiveness; receiver intelligence, self-esteem, and involvement; fea r appeals and order of presentation; distraction and forewarning; and a multitude of other contextual variables (see McGuire, 1985 for a recent review). Little attention was devoted to the dependent variable that serves as the target of the communication, although persistence of change over time was an early concern (see Cook and Flay, 1978). Of the mediating variables, only attention and comprehension were directly assessed.Thus, many studies contained a recall or recognition test to measure the degree to which the message was â€Å"received† (McGuire, 1968), that is, the degree to which the message was attended to and comprehended. Generally speaking, the purpose of the test was to make sure that reception did not vary across conditions of the experiment, and that whatever effects were observed could not be attributed to differences in reception. In other words, the goal was usually to rid the experiment of the mediating effect of reception, rather than to study reception i n its own right.Note also that the conceptual framework had little to say about the content of persuasive communication and what its role in the persuasion process might be. Message content was treated largely as a given, while the questions addressed had to do with the effects of contextual factors on the amount of change produced by the message in question. We shall see below that this approach to the study of persuasive communication was one of the major reasons for the failure of the Hovland tradition. Effects of source factors.One of the first lines of research initiated by the Hovland group dealt with the effects of communicator credibility (Hovland and Weiss, 1951), and innumerable studies since have manipulated this variable. Of all the contextual factors studied in the Hovland tradition, variations in source credibility have produced the most consistent findings. By and large, communicators high in expertise and trustworthiness tend to be more persuasive than communicators with low standing on these factors. However, even here, somePersuasive Communication Theory Page 6 contradictory evidence has been reported. Source credibility does not always increase the amount of change, and in some situations it can even have a negative effect (cf. McGuire, 1985, p. 263). Other source characteristics are generally found to have no simple or easily predictable effects on persuasion. The communicator's attractiveness, education, intelligence, social status, and so on can serve as cues for inferring expertise and can thus affect persuasion.However, these indirect effects do not appear to be strong enough to produce consistent results across different investigations. Effects of receiver factors. Age, gender, intelligence, self-esteem and other individual differences among receivers are rarely found to have strong effects on persuasion, and the results of different investigations are often inconsistent. Moreover, receiver factors are found to interact in complex ways with each other and with additional factors such as the complexity of the message, the type of arguments used, the credibility of the communicator, and so on.Effects of channel factors. A rather discouraging picture also emerged with respect to the effects of the medium of communication. While visual messages tend to be better liked and attended to than spoken or written messages, recall is sometimes better for written material, and adding pictures to print can be distracting (see McGuire, 1985, p. 283). In light of these contradictory effects, it is hardly surprising that empirical research on channel factors has produced largely inconsistent results.Effects of message factors. Some of the most complex patterns of findings are associated with message factors such as emotional versus nonemotional appeals, message style, and ordering of message content. With respect to the latter, consider for example whether one should state the message's basic position at the outset or at the end. Stating it at the beginning may have the advantage of clarity, making the source appear more trustworthy, and of attracting the attention of receivers sympathetic to the advocated position.It can also have the disadvantage, however, of lowering interest and antagonizing receivers initially opposed to the advocated position (McGuire, 1985). Other message factors can have equally complicated effects. To illustrate, consider the degree to which the message arouses fear or concern. Contrary to expectations, initial research (Janis and Feshbach, 1953) showed a low-fear message to be more effective than a high-fear message in producing compliance with recommended dental practices.Later research, however, has often found the opposite effect, and many investigations have reported no differences between high- and low-fear messages (for reviews, see Boster and Mongeau, 1985 and Higbee, 1969). Similarly inconsistent findings have emerged with respect to the effects of humor in persuasive comm unication (see Markiewicz, 1974). Retrospective In light of largely inconsistent research findings concerning the effects of contextual variables, many investigators became discouraged with the Hovland approach.Thus, after editing a book on attitude change in 1974, Himmelfarb and Eagly reached the following pessimistic conclusions: After several decades of research, there are few simple and direct empirical generalizations that can be made concerning how to change attitudes. In fact, one of the most salient features of recent research is the great number of studies demonstrating that the empirical generalizations of earlier research are not general, but contingent on conditions not originally apparent. (Himmelfarb and Eagly, 1974, p. 94. ) In fact, the complexity of the persuasion process noted by Himmelfarb and Eagly in their reference to contingencies has been a favorite explanation for the failure of the Hovland approach. This explanation holds that persuasion is influenced by so many different factors interacting with each other that only complicated, multidimensional research strategies can cope with the complexities. However, when investigators have studied higher-order interactions, no clear or replicable patterns have emerged.Indeed, there is serious doubt that the search for complicated interactions can ever be a viable strategy (cf. Cronbach, 1975; Nisbett, 1977). The role of the receiver. Besides failing to advance our understanding of the persuasion process, the complexity explanation had the Persuasive Communication Theory Page 7 unfortunate effect of hiding the basic shortcomings of the Hovland tradition and thus delaying the search for alternatives. As is usually the case, realizing where this approach went wrong is much easier in retrospect than it was at the time.Perhaps without meaning to, the Hovland group cast the receiver in a rather passive role whose task was to â€Å"learn† the information and recommended position presented in a message. Attention and comprehension would assure that the information was absorbed, and persuasion would thus follow automatically. This view of the receiver stands in clear contradiction to much that is known about information processing. People are far from passive receivers of information.Instead, they usually act on the information that is available, integrating it (Anderson, 1971), constructing interpretations of their own (Neisser, 1976), and going in many ways beyond the information given (Bruner, 1957). This is just as true in the domain of attitudes as it is in other areas of information processing. For example, research on impression formation has shown that people draw far-ranging inferences about the attributes of another person on the basis of very limited information (Asch, 1946; Fishbein and Ajzen, 1975; Wiggins, 1973).Such inferences are often said to rely on â€Å"implicit theories of personality† (Schneider, 1973) which might suggest, among other things, th at if a person is said to be hostile, he is also likely to be rash, aggressive, and inconsiderate. Several other lines of research demonstrate more directly the potential importance of inference processes in persuasive communication. Thus it has been shown that a persuasive communication designed to produce a change in one belief will also lead to changes in other, related, beliefs (McGuire, 1960a; Wyer and Goldberg, 1970).It is even possible to produce change by merely making people aware of inconsistencies among their beliefs or values (McGuire, 1960b; Rokeach, 1971) in a process McGuire has termed the â€Å"Socratic† effect: After reviewing their beliefs, people tend to change some of them in the direction of increased logical consistency. In short, there is every reason to expect that receivers exposed to a persuasive communication may engage in an active process of deliberation that involves reviewing the information presented, accepting some rguments, rejecting others, and drawing inferences about issues addressed that go beyond what was mentioned in the original message. The image of the passive learner fostered in the Hovland tradition is thus highly misleading, and misses the most important aspect of persuasive communication: the receiver's capacity for reasoning and for being swayed by the merits of a well-presented argument. Persuasion by the Peripheral Route The passive-learner view of the receiver implicit in the Hovland approach quite naturally led to a focus on the persuasion context.If the communicator's task is to make sure that receivers learn and absorb the contents of the message, concern turns to a search for conditions that facilitate attention to the message and comprehension of its arguments, with a concomitant lessening of interest in what the receiver does with the information that is received. Ironically, recent theory and research have established the potential importance of contextual factors, at least under certain wellspec ified conditions. Once we realize what these conditions are, we can begin to understand the reasons for the inconsistent findings of research conducted within the Hovland paradigm.In the previous section we emphasized the active role of the receiver who may engage in an elaborate process of reasoning about the merits of the arguments presented in the message. This view assumes, first, that receivers are in fact sufficiently motivated to exert the required cognitive effort and, second, that they have the ability to carefully process the incoming information. It now appears that contextual factors influence persuasion only when one or both of these conditions are not met (Chaiken, 1980; Petty and Cacioppo, 1981, 1986).Motivation to process the message and elaborate on it is largely a matter of the receiver's involvement. Different aspects of the self may be activated in a given situation, depending largely on the issue addressed, and as a result, different kinds of involvement can be generated. Specifically, the message may create involvement by dealing with receivers' enduring values, with receivers' ability to obtain desirable outcomes or avoid undesirable outcomes, or with the impression receivers make on others Persuasive Communication Theory Page 8 (Johnson and Eagly, 1989).However, when the message has few implications for enduring values, for important outcomes, or for selfpresentation, it produces little motivation to carefully deliberate its contents. Ability to process a message is related to factors internal to the receiver as well as to external factors. Among the internal factors are familiarity with the issues and cognitive ability and intelligence, factors that tend to increase capacity for information processing; and preoccupation with other matters and lack of time, which tend to reduce the ability to elaborate.External factors that increase the ability to process include message repetition and clarity of presentation, while external distraction and use of complicated language can reduce processing ability. Some of the contextual factors studied by the Hovland group can come into play when internal or external factors lower the receiver's ability to process the information presented in the message. Empirical Research When ability and motivation to process the message are low, receivers can use peripheral cues (Petty and Cacioppo, 1986) or cognitive heuristics (Chaiken, 1980) to form their opinions.Chaiken assumed that receivers of a message, even if they are not very greatly involved, nevertheless are motivated to hold a â€Å"correct† view on the issue. Since, under conditions of low motivation and ability, receivers are either incapable or unwilling to deal with the merits of the advocated position, they look for contextual or peripheral cues that might provide a basis for forming an opinion. Perhaps the most powerful such cue is the communicator's credibility, and it may be argued that this is the reason for the relatively consistent findings associated with communicator credibility.The heuristic strategy might in this case involve the following line of reasoning: â€Å"If this expert on the matter says so, it must be right. † This heuristic appears quite reasonable in that it accepts the position advocated by a credible source, even if one has not carefully scrutinized the arguments presented. Receivers can also use the source's attractiveness, or factors related to the message such as the number of arguments it contains, as peripheral cues. Thus, a message coming from a iked source might be viewed as more trustworthy, and one that contains many arguments (even if specious) might be seen as more reliable than a message that contains few arguments. Note, however, that these rules of thumb are far less convincing as a rational basis for accepting or rejecting an advocated position, and it is perhaps for this reason that factors of this kind often fail to have strong or consistent effe cts on persuasion. In any event, relying on heuristics obviates the need for careful message processing, and at the same time provides a basis for adoption of a position on the issue.Recent empirical research tends to support this view of the peripheral route to persuasion, although some complications have recently been noted (Johnson and Eagly, in press). Since excellent reviews are available elsewhere (Chaiken, 1987; Petty and Cacioppo, 1986), we limit our discussion here to an example concerning the effects of source characteristics. Recall that communicator attractiveness was one of the source characteristics studied in the Hovland paradigm that did not have a clear and consistent effect on persuasion.If treated as a peripheral cue used only when processing motivation or ability is low, more consistent findings tend to emerge. Attractiveness of the source has been varied by attributing the message to famous versus unknown individuals (Petty, Cacioppo, and Schumann, 1983) or to a likable versus an unlikable person (Chaiken, 1980). The investigators also manipulated the degree of involvement and found, as expected, that communicator attractiveness has a significantly greater effect on persuasion under low than under high involvement.Conclusions Work on the peripheral route to persuasion suggests that the source, message, channel, and receiver factors studied in the Hovland tradition can indeed influence the effectiveness of a message, but that this is likely to be the case only under conditions of low motivation or low ability to process the message. Such conditions can be obtained in the psychological laboratory that ensures some degree of attention by a captive audience even if the receivers have little interest in the topic or lack the ability to process the information presented (Hovland, 1959).In more naturalistic field settings, receivers who Persuasive Communication Theory Page 9 lack the motivation or ability to process a message can usually leave th e situation, while those who remain and are exposed to the message will tend to be sufficiently involved and able to process the information it contains. Persuasion by the peripheral route is clearly an inappropriate model for many realistic situations, and it is often inapplicable even in the artificial context of the laboratory.REASONING AND PERSUASION Even when it works, there is something distinctly unsatisfactory in the demonstration of change via the peripheral route, because the change brought about does not represent persuasion as we usually think of it. We noted at the beginning that it is the process of reasoning, the evaluation of the merits of arguments in favor and opposed to the advocated position, that is at the heart of persuasive communication. Persuasion involves more than simply oing along with an expressed point of view because of the presence of some peripheral cue; it requires that the advocated position be accepted only after careful scrutiny of the message an d after application of whatever other information the receiver can bring to bear. Moreover, change produced by the peripheral route is generally of little practical significance. Petty and Cacioppo (1986) noted that peripheral attitude change tends to be shortlived, tends to be susceptible to counterpropaganda (McGuire, 1964), and tends to have little effect on actual behavior.Clearly then, from both a theoretical and a practical point of view it would be to our advantage to focus less on the context of persuasion and more on the central processes that occur when a person is exposed to a message. Persuasion by the Central Route In the remainder of this chapter we examine persuasion that occurs when the receiver of a message is sufficiently able and motivated to give at least some scrutiny to the contents of the communication and to evaluate the merits of the arguments it contains.This has been termed the central route to persuasion (Petty and Cacioppo, 1981) and the deliberations re ceivers perform are known as systematic information processing (Chaiken, 1980). Instead of asking what makes a given message more effective, we must now ask how to construct an effective message. That is, what arguments, when systematically processed via the central route, will have the greatest impact on the receiver's attitudes and behavior? Before we can review what is known about this question, however, we must consider the role of the receiver in greater detail. The Elaboration Likelihood Model.The peripheral route to persuasion discussed earlier is one of two tracks a receiver can take in Petty and Cacioppo's (1981, 1986) elaboration likelihood model (ELM). The second track is persuasion via the central route. According to the ELM, central route persuasion depends on and is determined by the degree to which receivers elaborate on the information presented in the message. Briefly, during exposure to a persuasive communication, receivers are assumed to generate arguments of thei r own, either in support of the advocated position (pro arguments) or opposed to it (con arguments).These cognitive responses determine the direction and degree of change in attitudes and behavior. Increased motivation and ability to process the information in the message is, according to the model, associated with an increase in the number of cognitive responses (pro and con arguments) generated. To the extent that the number of arguments generated on the pro side exceeds the number of arguments on the con side, the receiver will change in the advocated direction. When elaboration leads to the production of more con than pro arguments, however, either no change or a â€Å"boomerang effect† (change in the opposite direction) may occur.From the communicator's point of view, therefore, motivation and ability to elaborate on message content is a two-edged sword. If, on balance, the thoughts generated by the receiver favor the advocated position, then the central route to persuas ion works to the communicator's advantage. On the other hand, if the receiver's cognitive responses consist predominantly of counterarguments, then elaboration on message content can be quite detrimental to the communicator's purpose.A number of studies, summarized in Petty and Cacioppo (1986), have examined the role of cognitive responses in the persuasion process. In these studies, cognitive responses are elicited Persuasive Communication Theory Page 10 in a free-response format following exposure to the message. The thoughts listed by the receivers are coded as either in favor or opposed to the advocated position, and the number of responses of each type is determined. Results, by and large, support the idea that the production of cognitive responses increases with motivation and ability to elaborate.Moreover, it is also found that changes in attitudes and behavior are consistent with the pattern of cognitive responses that are generated: a balance of thoughts in favor of the adv ocated position tends to be associated with change in the desired direction. 2 Yielding and Impact. Consideration of cognitive responses generated by receivers in the course of exposure to the message is, however, not sufficient to account for observed changes in attitudes and behavior. For change to occur in the central mode, some of the receiver's fundamental beliefs and values must undergo modification.Elaboration on the message may in fact lead to changes in cognitive structure, but evidence for the production of pro- or counter-arguments does not, in itself, assure that such changes have indeed taken place. Work on the elaboration likelihood model has focused primarily on cognitive responses to the message and has not dealt directly with changes in cognitive structure. The ideas discussed below are based on other recent work concerning persuasive communication via the central route (Fishbein and Ajzen, 1975, 1981).According to Fishbein and Ajzen, a message can bring about chang es in a receiver's cognitive structure in one of two ways. First, in a process termed yielding, acceptance of arguments presented in the message can produce changes in corresponding beliefs held by the receiver. Consider, for example, a pregnant smoker who initially is not aware that cigarette smoking can adversely affect the health of her unborn baby. This woman is now exposed to a message containing an argument and supportive evidence that establish the link between smoking and adverse health effects on the fetus.To the extent that the argument is accepted, it produces yielding in the sense that the woman's cognitive structure now contains a new belief that corresponds directly to the argument in question. That is, she now believes, as stated in the message, that smoking may have ill effects on her unborn baby. Changes in a receiver's primary beliefs, however, can extend far beyond the information directly contained in the message. Such changes that go beyond the information given are termed impact effects.To illustrate, the pregnant woman exposed to the message that smoking can have detrimental health effects on her fetus may infer that she would feel guilty if she did not stop smoking and that her doctor would want her to quit, even though neither argument was explicit in the message. It is also possible, however, for her to draw inferences that would work against the aims of the communicator. For example, the woman may unexpectedly form the belief that quitting would be even worse than continued smoking because it would result in overeating.These impact effects can, of course, play a major role in the woman's decision to quit or not to quit smoking. Evidence for the importance of considering yielding as well as impact effects can be found in a study on drinking reported in Ajzen and Fishbein (1980, pp. 218-242). Persuasive Argumentation The challenge facing a communicator trying to produce change via the central route is to create a message that will orig inate favorable responses, produce yielding to its arguments, and generate impact effects in accordance with the advocated change.Arguments contained in a message can be considered effective to the extent that they influence the receiver's cognitive structure. The essential question, therefore, is what makes an argument effective. In light of the fact that rhetoricians have written about argumentation for over 2,000 years, it is surprising how little empirical knowledge is available about the relative effectiveness of different types of arguments (McGuire, 1985). An analysis of this problem reveals at least three important aspects of an argument's effectiveness: novelty, strength, and relevance.Below we discuss each of these aspects in turn. Argument Novelty Persuasive Communication Theory Page 11 An argument contained in a message may well be accepted (i. e. , believed to be true), but if the receiver already held the belief in question before exposure to the message, no change in belief structure would result (Fishbein and Ajzen, 1981). To be effective therefore, an argument contained in a message must not be part of the receiver's initial belief system. Some empirical evidence for this proposition can be found in research on group decision making (Vinokur and Burnstein, 1974).In the course of group discussions, members who offer novel arguments in support of a given decision alternative are found to be more influential than members who raise points that are well known to the rest of the group. Argument Strength Besides being novel, an argument must also be strong if it is to sway the receiver to adopt the advocated position. A strong argument is one that tends to produce agreement (positive thoughts) and does not encourage generation of many counterarguments (Petty and Cacioppo, 1986). Although it is not clear what makes a strong argument, its strength or weakness can be empirically established.Earlier in this chapter we gave an illustrative example of a pe rsuasive argument taken from Petty and Cacioppo's (1986) research program. The argument asserted that instituting a senior comprehensive examination would raise grade point averages (see p. xx). This argument and the associated evidence make a strong case for the advocated position. Compare this to the following argument, also designed to generate support for a comprehensive exam. The National Scholarship Achievement Board recently revealed the results of a study they conducted on the effectiveness of comprehensive exams at Duke University.One major finding was that student anxiety had increased by 31%. At comparable schools without the exam, anxiety increased by only 8%. The Board reasoned that anxiety over the exams, or fear of failure, would motivate students to study more in their courses while they were taking them. It is likely that this increase in anxiety observed at Duke University would also be observed and be of benefit at other universities that adopt the exam policy (Pe tty and Cacioppo, 1986, p. 57). Although this argument is quite similar in structure to the strong argument presented earlier, it appears to present a much weaker case.In fact, this argument is typically found to generate many counterarguments. Clearly, in order to create an effective message, it is in the communicator's interest to select strong arguments and avoid including arguments that tend to elicit negative thoughts about the advocated position. Argument Relevance Related to the question of an argument's strength is its relevance to the advocated position. An argument may be strong in the sense that it generates few counterarguments and many pro arguments, but if it addresses an issue that is not directly relevant to the advocated position, it may fail to produce the desired effect.This point is often not sufficiently appreciated. Suppose a communicator would like to convince students to attend an anti-apartheid demonstration in Washington, D. C. , and thus exposes the studen ts to a persuasive message against apartheid in South Africa. Although the arguments contained in the message may be strong in the sense that they are believable and generate few counterarguments, the message may not be very effective as a means of inducing students to go to Washington.To make the message more relevant in terms of this goal, one would have to include strong arguments that deal more directly with the advantages of attending the planned demonstration. A relevant argument, then, is one that changes those primary beliefs of the receiver that are directly related to the target of the influence attempt, that is, to the attitude or behavior the communicator wishes to affect. Different target variables are based on different primary beliefs, and an effective message must be tailored to fit the target in question.General discussions of different target variables and their respective foundations of primary beliefs can be found in Fishbein and Ajzen (1975, 1981) and in Fishbei n and Manfredo (Chapter xx, this volume). It is beyond the scope of this chapter to provide an in-depth review. Briefly, Fishbein and Ajzen distinguish Persuasive Communication Theory Page 12 among beliefs, attitudes, intentions, and behaviors as possible targets of a persuasive communication. To effect a change in any one of these target variables, the message arguments must be directed at the primary beliefs that provide the basis for the target in question.The first step in the construction of a message, therefore, requires a decision about the relevant primary beliefs, a process that cannot be left to intuition but must be guided by a model of the target's determinants. Social psychologists have discussed a variety of approaches to understanding beliefs and attitudes and their relations to behavior, but perhaps the most popular models can be found within the framework of the theory of reasoned action (Fishbein and Ajzen, 1975; Ajzen and Fishbein, 1980) and its recent extension, the theory of planned behavior (Ajzen, 1985, 1988).The discussion below considers each target variable in turn; however, a full understanding of the process is gained only by considering the relations among the different variables. Changing behavior. According to the theory of reasoned action, many behaviors of interest to social psychologists are under volitional control and, hence, are in an immediate sense determined by the intention to perform the behavior in question. A successful persuasive communication designed to change a certain behavior must therefore contain arguments that will bring about a change in the antecedent intention. The theory of planned behavior oes beyond the question of intended action, taking into account the possibility that the behavior of interest may not be completely under volitional control. To be successful, the message may have to provide information that will enable the receiver to gain volitional control and overcome potential obstacles to perfor mance of the behavior. A review of evidence in support of these propositions can be found in Ajzen (1988). Changing intentions. The antecedents of behavioral intentions are, according to the theory of reasoned action, the person's attitude toward the behavior and his or her subjective norm.The attitude toward the behavior refers to the evaluation of the behavior as desirable or undesirable, and the subjective norm is the perceived social pressure to perform or not to perform the behavior in question. The theory of planned behavior again adds to this model a consideration of volitional control. When issues of control arise, intentions are influenced not only by attitudes and subjective norms but also by perceived behavioral control (Ajzen and Madden, 1986; Schifter and Ajzen, 1985).A persuasive communication designed to influence intentions (and thus also behavior) can be directed at one or more of the intention's three determinants: attitudes, subjective norms, and perceived behavio ral control. Changing attitudes. We arrive at the level of primary beliefs as we consider the determinants of a person's attitudes. According to the theory of reasoned action, attitudes are a function of salient beliefs about the attitude object (a person, group, institution, behavior or other event). Each salient belief links the object to an attribute or to an outcome in the case of a behavior.The attitude is determined by the strength of these beliefs and by the evaluations associated with the attributes (Fishbein, 1963; Ajzen and Fishbein, 1980). Beliefs about the attitude object that are salient prior to presentation of the message can be elicited in a free-response format. The message is then constructed such that it will either change some of the existing beliefs, either in their strength or their evaluations, or introduce new beliefs into the belief system. Changing beliefs. To change a specific belief on an issue, the persuasive communication has to address some of the info rmation on which the belief is based.Several probabilistic models that link prior information to a given belief have been proposed and validated (McGuire, 1960b; Wyer and Goldberg, 1970; for a review see Slovic, Fischhoff, and Lichtenstein, 1977). These models suggest that the information introduced by the persuasive communication must be information from which the belief in question can be probabilistically inferred. Conclusions The focus in recent years on the central route to persuasion holds great promise for a better understanding of persuasive communication.This route deals with the essence of the persuasion process, with changes in the fundamental beliefs on which the receivers' attitudes and actions are based. Although much remains to be done, social psychologists have gained considerable insight into some of the cognitive processes that are at work during and Persuasive Communication Theory Page 13 after exposure to a persuasive communication, and into the practical aspects of constructing an effective message. SUMMARY This chapter provided a brief historical perspective on persuasive communication theory in social psychology.No attempt was made to discuss all theoretical developments in detail as this task would require a book in itself. Instead, the focus was on a few dominant lines of theoretical development, from the beginnings of scientific research on persuasion in the 1940s to the present day. The work initiated by Hovland and his associates tended to view the receivers of a persuasive communication as passively learning the information presented and then changing their beliefs and attitudes accordingly. This view led to a concern with contextual factors, and virtual neglect of the contents of the communication and its processing by the receiver.Few generalizable conclusions emerged from the research guided by this approach, and by the late 1960s the failure of the Hovland approach was widely acknowledged. Progress was recorded when attention t urned from contextual or peripheral factors to persuasion via the central route. Contextual factors were found to be important only under conditions of low involvement or low ability to process the message. It was discovered, however, as a general rule, that receivers of a message are far from passive, engaging in an active process of analyzing and elaborating on the information presented.It became clear that the effects of a persuasive communication could not be understood unless careful attention was given to these cognitive processes. Theoretical and empirical developments of the past two decades have enabled us to consider receivers' cognitive responses during exposure to a message, yielding to the arguments contained in the message, and the message's impact on other beliefs not explicitly mentioned. These developments have also resulted in a much closer examination of the contents of persuasive communications, with an eye toward selecting arguments that will have the maximum ef fect on the target of the influence attempt.In this way, the theoretical developments of recent years have important implications for the practitioner who is concerned with constructing effective persuasive communications. Persuasive Communication Theory Page 14 REFERENCES Ajzen, I. 1985. From intentions to actions: A theory of planned behavior. In: J. Kuhl & J. Beckmann, eds. Action-control: From cognition to behavior. Heidelberg: Springer: 11-39. Ajzen, I. 1988. Attitudes, personality, and behavior. Chicago: Dorsey Press. Ajzen, I. , & Fishbein, M. 1980. Understanding attitudes and predicting social behavior. Englewood-Cliffs, NJ: Prentice-Hall. Ajzen, I. & Madden, T. J. 1986. Prediction of goal-directed behavior: Attitudes, intentions, and perceived behavioral control. 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