tured scenarios on compliance is not due to additional information provided by the scenario. Instead, an interpretation based on the availability heuristic is.
Journal of Personality and Social Psychology 1982, Vol. 43, No. 1,89-99
Copyright 1982 by the American Psychological Association, Inc. 0022-3514/82/4301 -0089100.75
Self-Relevant Scenarios as Mediators of Likelihood Estimates and Compliance: Does Imagining Make It So? W. Larry Gregory
Robert B. Cialdini
New Mexico State University
Arizona State University
Kathleen M. Carpenter Claremont Graduate School A series of studies was conducted to determine the viability of a scenario procedure as a compliance technique. In four experiments, subjects who, through the use of a structured scenario, were led to imagine themselves experiencing certain events came to believe more strongly that the events would befall them. This promotive effect of the scenario procedure on probability or likelihood estimates occurred for both positive events (e.g., winning a contest) and negative events (e.g., being arrested for a crime) and occurred in both laboratory and field contexts. Furthermore, and crucial to its relevance for compliance, the scenario procedure was shown to influence not bnly probability judgments but also behavior. Homeowners who imagined themselves utilizing a cable television service were subsequently more likely to subscribe to such a service when requested to do so weeks later. Finally, it was determined that the effect of structured scenarios on compliance is not due to additional information provided by the scenario. Instead, an interpretation based on the availability heuristic is favored.
Evidence from a study by Carroll (1978) nitively available (i.e., it springs to mind eassuggests that subjects who are made to imag- ily), it will be perceived as likely. Carroll ine the occurrence of a social event (e.g., the (1978) argued that having subjects imagine election of a political candidate) through the the occurrence of an event, via a scripted use of elaborate scenarios come to believe scenario, makes images of the event subsemore strongly that the event will take place. quently more available and, consequently, Carroll (1978) explained this finding in makes the event appear more probable. terms of the availability heuristic identified Although not specifically implicated by by Tversky and Kahneman (1973). Avail- the Carroll (1978) data, the power of a ability is a heuristic strategy sometimes em- scripted scenario (i.e., a series of events ployed by persons who are called upon to linked together in narrative form) to influmake frequency or probability judgments. ence probability judgments may have imTo the extent that an idea or event is cog- portant ramifications for behavioral compliance; that is, a requester may be more successful in gaining compliance with a rePreparation of this manuscript was facilitated by New quest if the target person has first imagined Mexico State University College of Arts and Sciences a scenario of himself or herself performing Minigrant 1-3-43545 to the first author. Experiments 1, 2, and 3 are taken from the first two the requested behavior. Such an enhancestudies of the first author's dissertation submitted to ment of compliance could occur for at least Arizona State University in partial fulfillment of the two reasons. First, the elevated expectancy requirements for the PhD, and Experiment 4 comprises that an event will take place resulting from a portion of the third author's senior honors thesis in psychology. Both were supervised by the second author. a scenario procedure (Carroll, 1978) could The authors would like to express their appreciation work directly on behavior: Because people to Billie Allison and Janice Gregory, who served as the are reluctant to abandon or disconfirm their female experimenters in Experiment 3. Requests for reprints should be sent to Larry Gregory, expectancies (e.g., Aronson & Carlsmith, Department of Psychology, New Mexico State Univer- 1962; Sherman, 1980; Weaver & Brickman, sity, Las Cruces, New Mexico 88003-3452. 1974), especially those for which they have 89
90
L. GREGORY, R. CIALDINI, AND K. CARPENTER
imagined an account (e.g., Anderson, Lep- action pattern, the scenario structure itself per, & Ross, 1980; Sherman, Skov, Hervitz, provides information about how the action & Stock, 1981), these newly heightened ex- pattern could be accomplished in a way that pectancies could stimulate consistent behav- the subjects would not have generated themior. Second, and not incompatible with the selves. In this case, it would not be the cogfirst possibility, if subjects are made via the nitive availability of these actions that would scenario procedure to believe that they are make them seem more likely but, rather, the more likely to perform an act, they may raw information about how they might be develop a more favorable attitude toward the performed. Accordingly, it would be imporact to maintain a consistent self-perception tant to remove the raw-information alter(Bern, 1972). This changed attitude, then, native/artifact as a likely mediator of the could spur behavior. scenario effect. Thus, there is reason to believe that a sceThis article reports the outcome of a renario procedure could be employed as an search program designed to meet the preeffective compliance technique. Before one viously mentioned conditions. Experiments can have much confidence in such a possi- 1 and 2 were intended to assess the ability bility, however, several conditions must be of the scenario procedure to reliably affect met. First, greater evidence should be gen- subjects' likelihood estimates for self-releerated for the ability of scenarios to affect vant events. Experiment 3 sought to replicate probability judgments. At present, the rel- those findings in a context that minimized evant evidence is weak. For example, in Car- a demand-characteristics interpretation of roll's (1978) studies, the scenario procedure the basic effect. Experiment 4 investigated produced significant effects for certain ex- the effectiveness of the scenario procedure pectancies but not for others. Second, if a as a compliance technique able to influence scenario approach is to be germane to per- rather costly overt actions. Experiment 4 sonal-compliance behavior, it must be shown also provided evidence for the explanatory to affect likelihood estimates for self-rele- power of raw information as a mediator of vant acts; that is, the perceived probability the enhanced compliance. that one will perform an action must rise after one has imagined oneself so acting in Experiment 1 a scenario. To date, no such data exist. Third, the possibility of a demand-charac- Method Subjects. Forty-eight male introductory psychology teristics (Orne, 1962) explanation for the general phenomenon must be largely re- students from Arizona State University participated as in exchange for experimental credit toward the duced. The Carroll (1978) findings could be subjects fulfillment of a departmental methodology requirement. interpreted as stemming from experimental- Students were led to believe that they were participating demand pressures. Therefore, it is necessary in a study of the plea-bargaining process. Procedure. Subjects in the experimental condition to demonstrate the promotive effects of scenarios on likelihood estimates in contexts not heard a tape-recorded scenario (adapted from Gregory, & Linder, 1978) that described either (a) how readily susceptible to demand effects. Fourth, Mowen, they were arrested for but had not committed armed a significant effect of the scenario procedure robbery or (b) how they actually committed an armed on overt compliance with a request should robbery and were subsequently arrested.1 These recordbe demonstrated. Furthermore, this compli- ings began with instructions requesting the subjects to relax and imagine that the events described in the tape ance action should be relatively extreme to were actually happening to them. References to the subprovide some evidence of the power of the ject within the tape were in the second person (e.g., technique. Finally, an investigation of fac- "you are forced hard against a car and searched"). Foltors that could mediate the technique's ef- lowing the tape, to lend credibility to the cover story, fectiveness should be undertaken. For in- these subjects completed a booklet requesting them to various details of the scenario and make various stance, it would be possible to interpret the recall ratings (e.g., whether their defense attorney believed technique's success in a more straightforward way than via the availability heuristic. 1 A copy of the script used in this experiment, and in Perhaps in the course of instructing subjects all subsequent experiments described herein, can be obto imagine themselves performing a specific tained from either the first or second author.
SELF-RELEVANT SCENARIOS that they were guilty or innocent, estimates concerning the amount of evidence for and against them). The dependent variable was assessed in a final question that required subjects to make an estimate of how probable it was that they could someday be arrested for armed robbery: "How likely is it that you might someday be arrested for armed robbery, regardless of whether you are innocent or guilty?" Their responses were made on an interval probability scale, beginning with 0% and incrementing by 5% up to an endpoint of 100%. The endpoints were labeled, respectively, "absolutely no chance" or "absolutely will be arrested." Subjects in the control condition heard no scenario and only completed the dependent measure concerning how probable it was that they could someday be arrested for armed robbery. All subjects were debriefed following completion of the experiment.
91
Procedure. Subjects were led to believe they were participating in a pilot study for a future memory experiment. A cover sheet on the experimental questionnaire informed them that the researcher would eventually be investigating some of the factors that affect human memory. We explained that the current questionnaire contained one of several scripts developed for possible future use as a stimulus script in memory experiments. The cover sheet explained that the scripts had to be evaluated as to whether they were too difficult (few people could remember many details of them accurately) or too easy (too many people could remember everything about them). Thus, the subjects' task was to read the script carefully and imagine that the events described were actually happening to them (purportedly to make the subjects' classroom evaluation situation more similar to the ultimate situation in which the scripts would be utilized). Only two scripts were actually used. The experimental script consisted of a two-page, single-spaced account of the subject traveling with a companion to a shopping mall and, while shopping, entering a contest and winning the second prize.—a free vacation trip to Hawaii. The control-condition script described a similar trip to a shopping mall but made no mention of a contest and terminated with the subject traveling to a local library to borrow some books for a term paper. Both scripts were in the second person, present tense (e.g., "you pass by a booth selling pastries, and your friend buys one and splits it with you"). Dependent measures. After reading the scripts, subjects completed 10 brief questions concerning the contents of the script, indicated how believable they found the script to be on a 7-point scale (with 1 labeled "extremely believable," 4 labeled "neither," and 7 labeled "extremely unbelievable"), and indicated their mood on a 7-point scale (with 1 labeled "extremely good mood," 4 labeled "neither," and 7 labeled "extremely bad mood"). The dependent variable of interest, the perceived probability of winning a vacation, was assessed by informing subjects that the possibility existed that their beliefs about certain events could affect their memory for the script; therefore they were requested to complete six items that required them to indicate how probable they felt certain events were to occur. The probability of winning a vacation was one of these six items, and its position was varied randomly across the six possible positions. Probability was assessed with an interval scale similar to that used in the previous experiment. Subjects were debriefed after completing the questionnaire.
Results and Discussion An analysis of variance (ANOVA) performed on subjects' probability estimates revealed that experimental-condition subjects were significantly more likely to believe that they could someday be arrested for armed robbery (M = 17.50%, SD = 17.04, n = 32) than were control-condition subjects (M = 9.06%, SD = 7.12, n = 16), F(l, 46) = 3.58, p < .032 (one-tailed). Although it appears that subjective probability estimates for a personally relevant event are elevated as a function of an available scenario, a potential flaw exists in Experiment 1. Only the subjects in the experimental condition heard a scenario for which they were to imagine that the events were actually happening to them. It is conceivable that the act of imagining any event makes it easier to imagine subsequent events. Thus, it is possible that the obtained difference between the experimental-condition subjects and the control-condition subjects could have been obtained using any scenario, an artifact unrelated to the concept of available instances. Thus, a subsequent study was con- Results and Discussion ducted in which both conditions were exAn ANOVA performed on the subjects posed to scenarios. subjective probability estimates of winning a vacation was significant, F(l, 98) = 9.28, Experiment 2 p < .002 (one-tailed). Subjects who had read Method the experimental-condition scenario believed Subjects. Sixty-two females, 32 males, and 6 stu- they were more likely to win a vacation (M = dents who failed to indicate their sex served as subjects. 37.94%, SD = 26.63, n = 52) than were conAll were juniors enrolled in a psychology course in a trol-condition subjects (M = 23.02%, SD = Phoenix, Arizona, metropolitan area high school. Subjects participated in the experiment by completing a 21.87, n = 48). questionnaire in their class. Although no specific predictions were
92
L. GREGORY, R. CIALDINI, AND K. CARPENTER
made for any other variables assessed, exploratory analyses were performed on each of them. A significant difference was obtained for the subjects' memory scores for the two scenarios, F(l, 98) = 5.49, p < .02. Subjects in the experimental condition (M = 7.65, SD = 1.25), answered more items correctly than did control-condition subjects (M = 6.96, SD = 1.70). However, it must be acknowledged that due to the differences in the scenarios, the memory questions concerning them were comparable, but not all were identical. They were included in the experimental booklets as filler items to further convince subjects of the validity of the cover story. Additionally, the correlation between total number of memory items answered correctly and the probability estimates for winning a vacation was computed for the experimental-condition subjects and was nonsignificant, r(50) = -.02. Although it appears that the actual mertiory for the specific details of the scenarios is unrelated to probability estimates, it should be noted that memory scores were uniformly high, which could preclude the possibility of obtaining a significant correlation between memory scores and probability estimates. Also significant was the analysis of the subjects' ratings of the believability of the scenarios, F(l, 98) = 8.82, p < .004. Subjects' ratings of the experimental-condition scenario (M = 2.94, SD = .85) indicate that it was less believable than the control-condition scenario (M = 2.44, SD = .85). Although a significant difference between the two conditions was found on the believability measure, the scores for the experimental condition were on the "believable" end of the scale. Moreover, the effect does not appear to have mediated the subjects' probability estimates. The correlation between the estimates of the probability of winning a vacation and believability ratings (computed for the experimental-condition subjects only) was nonsignificant, r(50) = -.20. Finally, there was a significant difference in the subjects' ratings of mood as a function of the scenario that they read, F(l, 98) = 20.32, p < .001. The ratings of subjects in the experimental condition (M = 2.88, SD = .90) indicated that they were in a significantly better mood than subjects in the con-
trol condition (M = 3.69, SD = .88). Thus, the possibility exists that mood was mediating the subjects' estimates of probability. Suggestive evidence against this possibility is the lack of a significant correlation between mood and probability estimates of winning a vacation for the experimental-condition subjects, r(50) = .08. In this experiment, subjective probability estimates of winning a vacation appear to have been increased by providing subjects with an available scenario depicting that event. Since both experimental- and controlcondition subjects were required to imagine that the events in a scenario were happening to them, it appears that the act of imagining by itself does not serve to increase probability estimates for events other than the one imagined. Experiment 3 A more thorough examination of the processes that generated these results must be attempted, but a prior question concerns the validity of the procedures for examining the effects of scenarios on estimated probability. In the two experiments presented thus far, subjects either heard or read scenarios describing the occurrence of an event. Subjects then responded to questions about the scenarios and were required to judge the probability that the event described could happen to them. It is conceivable that the present data, and Carroll's (1978) data, could be the simple result of demand characteristics. Subjects in the experimental conditions may be making their probability estimates after inferring that the researcher wants them to believe that the event described in the scenario could happen to them. Thus, before undertaking further research concerning the effects of scenarios on the probability estimates of individuals, it is imperative that we establish that these effects are not solely the result of demand characteristics. Method Subjects. Thirty-nine female and 19 male introductory psychology students from Arizona State University participated as subjects in exchange for experimental credit toward the fulfillment of a departmental methodology requirement.
SELF-RELEVANT SCENARIOS Procedure. As in Experiment 2, students were led to believe they were aiding with the evaluation of scripts for possible use in future experiments on memory. Subjects in the experimental condition read two scripts (counterbalanced across subjects in their order of presentation). One script described their arrest for petty theft, while the other described their arrest for shoplifting. In the former scenario, the subject is described as deliberately stealing a cassette recorder from a liquor store and being apprehended by the owner and turned over to the police, who book the subject. In the latter scenario the subject is described as placing a box of Band-Aids in a coat pocket while continuing to shop in a drug store, with the intention of paying for them. The subject is described as being detained by the store manager and picked up by a police officer. Each scenario was followed by 10 questions about its contents and by 2 questions concerning its credibility and the mood in which it left the subject. These latter 2 questions were identical to those described in the previous study. Control-condition subjects read two counterbalanced scenarios. One was the same scenario used in the control condition of Experiment 2, while the other described the subject applying for and interviewing for a part-time job with an investment company. As with the experimental condition, each scenario was followed by 10 questions concerning its contents and 2 questions assessing its believability' and mood. All scripts were in the second person, present tense. The experiment was conducted in the early evening hours, and it was assumed that most students would go home after participating. Thus, after subjects had read either the control- or experimental-condition scenarios and had completed the questions concerning the contents and believability and their mood, they were dismissed. At that time, the male experimenter gave the names and telephone numbers of the participants* to a female experimenter who was blind to each subject's experimental condition. At Arizona State University, the telephone numbers of students are collected routinely as they register in advance to participate in experiments. Thus, it was not necessary to obtain telephone numbers from subjects during the course of the experiment. After waiting 30 minutes from the time that the subjects completed the experiment, the female experimenter telephoned the subject. When someone answered the telephone, the experimenter gave a fictitious name and asked for the subject by name. After ascertaining that she was speaking to the subject, she explained that she was pooling selected individuals on certain issues for the Tri-City Consumer Advocacy Project (CAP, a fictitious organization). She asked subjects if they would be willing to take 2 minutes to answer a few questions and if they would allow their opinions and ideas to be represented in recommendations that would be made on the basis of the survey. A standard set of responses was employed if subjects had any questions about the organization, how their names had been obtained, the purpose of the poll, and so forth. If a subject was reluctant to participate, the experimenter explained that her or his particular responses were invaluable, given the way CAP researchers selected their samples. She also offered to send her or him a copy of the results when available and assured the subject of the confiden-
93
tiality of her or his responses. Once a subject had agreed to participate, the experimenter asked the subject her or his age. She then explained that the topic of the poll was judicial reform and that the CAP was interested in the penalities the subject considered appropriate for various crimes. The experimenter explained that she would name in random order various crimes for which individuals are arrested and that the subject was to respond with her or his opinion on how many years or months in prison the sentence should be for that crime. Subjects were told that they could also indicate that no time should be served or that the death penalty should be imposed. Probability assessment. After working through a list of 19 crimes, which included shoplifting and petty theft (separated in the list by 8 other crimes), the experimenter explained that she would go through the list again, with the subject indicating whether he or she personally knew anyone who had been arrested for that particular crime. After completing this task, the experimenter went through the list one final time asking the subject how probable it was that he or she could someday be arrested for that crime, explaining the meaning of 0 and 100% probability and requesting subjects to round their answers off to the nearest 5%. Subjects were reminded that they were not being asked how likely it was that they would actually commit the crime, nor how likely it was that they would be convicted. Suspicion probe. After collecting this information, the experimenter completed a probe for suspicion, moving from general questions to a specific question. This portion of the script read, One more thing before I'm through. Recently, we have had some trouble getting individuals to assist us with our surveys. We think this is in part due to the ever increasing number of sales organizations that are conducting their business by telephone. Since we are continually interested in improving our image with the public and in improving the quality of our work, I'd like to get your response to just three more questions. First, do you have anything to add or do you have any comments? Second, do you have any idea why we called you? Third, at any time during the call, did you feel that the reason that I called was anything other than what I described? After recording the subject's responses, the experimenter thanked the subject for her or his time and terminated the call. The experimenter then recorded the time. Subjects were debriefed by mail.
Results and Discussion Of the 58 subjects who read the scenarios, 6 males and 8 females could not be contacted by telephone, and 4 females refused to participate in the telephone survey. This left 13 males and 27 females with complete data. One female was deleted from this sample. She had indicated a 40% probability for being arrested for sexual assault. None of the other females in the study indicated any
94
L. GREGORY, R. CIALDINI, AND K. CARPENTER
probability greater than 0% for this crime. This fact suggests that the subject was not responding to the survey in a valid mariner. None of the subjects indicated any suspicion that the telephone survey was anything other than it was represented as being. A few subjects were curious as to where the CAP had obtained their names, for which the experimenter gave a standard reply concerning the various lists used by CAP researchers to derive samples (church memberships, service organizations, college enrollments, voter registration lists). Still others volunteered that they originally had thought they were to be targets of some sales or marketing pitch but had quickly realized they were wrong. For the major dependent variable of interest, an average score was derived by summing each subject's probability estimates for being arrested for shoplifting and petty theft and dividing by two. An ANOVA on this score yielded a significant result, F(l, 37) = 5.22, /x.015 (one-tailed). Inspection of the means revealed that the experimental-condition subjects estimated higher probabilities for someday being arrested for the two crimes (M = 16.37%, SD = 25.45, n = 20) than did control-condition subjects (M = 2.50%, SD = 7.45, n = 19). These data were obtained outside the laboratory in a context seemingly devoid of experimental cues for the desired response. Thus, the results of the first two experiments apparently cannot be accounted for by relying exclusively on the effects of experimental demand characteristics. No significant differences were obtained for the subjects' memory scores for the scenarios, averaged across the two scenarios that each group of subjects read (F < 1, ns). Nor were there any significant differences between the two conditions for the subjects' ratings of the believability of the scenarios, averaged across the two scenarios that each group of subjects read (F < 1). For the experimental condition, Pearson product-moment correlation coefficients were computed to examine the relationship between average memory scores for the two scenarios and the average probability rating for being arrested for petty theft and shop-
lifting. A similar correlation was computed for believability and probability. No significant relationships were obtained in either of these analyses, both rs(18) < .21,p > .39. A significant difference was obtained for subjects' mood scores (averaged across the two scenarios that each group of subjects read), F(l, 37) = 10.52, p< .003. Subjects in the experimental condition were in a significantly worse mood after reading their scenarios (M = 4.30, SD = .68) than were the control-condition subjects (M = 3.55, SD = .76). A correlational analysis relating average mood scores for the two experimental^condition scenarios to the average probability rating for being arrested for petty theft and shoplifting was not significant, K18) = .22, p > .35. Thus, a linear relationship between mood and probability does not appear to exist in this study. Additional analysis revealed that no significant differences existed between the two groups in the amount of time that elapsed between the reading of the scenarios and the telephone contact, r(37) = 1.31,/j > .20 (experimental-condition M = 96.33 minutes, SD = 57.09; control-condition M = 133.22 minutes, SD = 114.06). For the experimental .condition only, a correlation was computed between elapsed time and the average probability-estimate score for being arrested for shoplifting and petty theft. This, too, was nonsignificant, K18) = .17, suggesting that the effects on probability of the scenarios did not diminish as a function of the limited time that elapsed between reading the scenarios and the assessment of the probability estimates. One final analysis revealed that subjects did not differ in their recommended sentences for the various crimes as a function of experimental condition. Experiment 4 Tversky and Kahneman (1973) argued that "the plausibility of the scenarios that come to mind, or the difficulty of producing them, then serve as a clue to the likelihood of an event" (p. 229). Since, in our studies, subjects did not construct the original see-
SELF-RELEVANT SCENARIOS
narios (also true of the Carroll, 1978, experiments), the subjects' perceptions concerning the difficulty of producing a scenario were bypassed and should not have served as a cue in making probability estimates. Thus, we argue that the crucial elements of our studies were the plausible scenarios that we made available to our subjects. These scenarios served as readily available instances and resulted in the biased probability estimates obtained. However, another possible explanation exists. Although demand characteristics have been minimized as an alternative explanation for the reported effects in these experiments, it is possible that simple information differences between the control and experimental conditions could account for the results. In the experiments presented thus far, the experimental scenarios depicted situations that subjects are unlikely to have ever considered; hence it is possible that this information alone, and not availability, led to upward biases of subjects' probability estimates for the events described. A similar explanation could account for the results of Carroll's experiments. Therefore, it was necessary to design an experiment in which identical information was presented to subjects in both the experimental and control conditions, with the scripts differing only in the self-relevance of the information presented. Thus, in Experiment 4, the control-condition subjects were provided with information concerning an event, whereas the experimental-condition subjects received the same information in the form of a scenario requiring them to imagine the event as though it were happening to them. In this experiment, in addition to probability beliefs, behavioral measures were included to explore the possibility that imagining a scenario could influence subsequent behavior. Were this demonstrated to be the case, the scenario procedure might have newfound status as a compliance technique. Method Subjects. Subjects were residents of two middleclass neighborhoods contacted by a door-to-door can-
95
vasser in Tempe, Arizona, a city in the Phoenix metropolitan area. Thirty-one of the subjects were male, 47 were female, and there was one "subject" whose responses were the mutually-agreed-upon responses of the male-female couple residing in the home. Stimulus materials. The experiment was done in conjunction with a local cable television company. Literature pertaining to cable television (CATV) was obtained from the company and was used to create the stimulus materials for the "information" (control) condition. For the "imagination" (experimental) condition, a scenario was constructed utilizing the same information as the control condition but emphasizing that subjects were to imagine themselves experiencing the benefits and features of the service. A few sample paragraphs will elucidate the differences between the two conditions. The following is an excerpt from the information condition. CATV will provide a broader entertainment and informational service to its subscribers. Used properly, a person can plan in advance to enjoy events offered. Instead of spending money on the babysitter and gas, and putting up with the hassles of "going out," more time can be spent at home with family, alone, or with friends. The parallel passage from the imagination condition follows: Take a moment and imagine how CATV will provide you with a broader entertainment and informational service. When you use it properly, you will be able to plan in advance which of the events offered you wish to enjoy. Take a moment and think of how, instead of spending money on the babysitter and gas, and then having to put up with the hassles of "going out," you will be able to spend your time at home, with your family, alone, or with your friends. Procedure. Subjects were contacted at the door of their residence by a female experimenter, who indicated that she was doing a survey of attitudes toward cable television for a class project. The experimenter displayed her student identification card and a badge stating, "Student Researcher, Cable TV Survey, Arizona State University." After the subject had agreed to the survey, she explained that to insure that everyone who answered the questionnaire had equal information about CATV, she would read the subject a short description of some of the aspects of CATV taken from literature supplied by the local cable company. The script appropriate to the experimental condition to which the subject had been assigned randomly prior to contact was then read to the subject. Dependent measures: Questionnaire. After the subject had heard the script, he or she was asked a series of questions. The first question required subjects to indicate how likely they felt that CATV would be as popular as regular television. Responses were collected on a 7-point scale ranging from "very likely" (7) to "very unlikely" (1). Using an identical scale, the second question asked subjects how likely they thought CATV would be something they wanted. The third question,
96
L. GREGORY, R. CIALDINI, AND K. CARPENTER
Table 1 Significance Tests, Means, and Standard Deviations for the Interview Questions
Question
F(\, 77)
1. Likely CATV will be as popular as regular television 2. Likely subject will want CATV 3. Positive-negative attitude toward CATV 4. Likely subject will obtain further information 5. Likely subject will subscribe to CATV 6. Prior information about CATV 7. Prior information left subject with favorable or unfavorable view of CATV
Information condition
Imagination condition
M
SD
M
SD
< .001.
imagination procedure appears to have had a marked positive effect on compliance rates. Since the data reveal that both the subjects' likelihood estimates concerning subscribing to CATV and their attitudes toward CATV were enhanced by the imagination procedure, the question arises as to which of the two (if not both) plays a more prominent role in mediating the subsequent behavior of subscribing to CATV. Since the experiment was designed to rule out information differences as an alternative explanation for the effects of imagining on probability estimation, we can only speculate on the processes influencing the behavioral data. Pearson product-moment correlations were computed between experimental condition, the likelihood of subscribing, positive-negative attitude, and actual subscriptions (point-biserial correlations were computed where appropriate, but they yielded results identical to the Pearson product-moment correlations). Table 3 displays the results of these correlations. As would be expected, experimental condition correlates significantly with subscribing. However, subjects' estimates of the likelihood that they would subscribe correlate much higher with actual subscriptions. Attitude toward CATV correlates significantly with subscribing as well, but to a significantly lesser extent than likelihood, t(76) = 3.10, p < .002. In fact, the correlation between attitude and subscribing with the effects of likelihood partialed out is r(76) = .05, ns, while the correlation between likelihood and subscribing with the effects of attitude partialed out is r(76) = .51, p < .001. It is clear that likelihood plays a bigger role in these data. This is not to say that attitude does not play a role. If attitude
toward subscribing had been assessed (Ajzen & Fishbein, 1980; Fishbein & Ajzen, 1975), these correlations might have been different. However, the data do suggest that expectancies for behavior did play a large role in mediating the behavior (Aronson & Carlsmith, 1962; Sherman, 1980; Weaver & Brickman, 1974). General Discussion The recurring pattern of results in the series of experiments reported herein supports the predictions derived from the Tversky and Kahneman (1973) notion of cognitive availability. Subjects were provided with highly detailed scenarios describing events that they imagined were happening to them. Relative to control subjects, subjects who imagined scenarios rendered elevated subjective probability estimates for the occurrence of those events that were the subject of the scenarios. Although conceptually replicating Carroll's (1978) findings, the present studies have gone beyond the early data in extending the literature concerning available instances generated by scenarios. In our studies, the events that were manipulated in the scenarios were of a personal nature and described events that could happen to subjects themselves. Further, Experiment 3 diminished experimental demand characteristics as an alternative explanation of the findings. This finding is especially crucial because the experimental results produced by both the methodology employed in our first two experiments and Carroll's two experiments are readily susceptible to the demand-char-
SELF-RELEVANT SCENARIOS
acteristics explanation. Although experimental demands may have contributed to the effects of these experiments, the methodology of the third experiment, wherein the dependent variables were assessed outside an experimental context in the absence of suspicion in any subjects, minimizes the likelihood of demand characteristics as the prime mediator of the observed findings. Experiment 4 provides clear evidence that differences in the information provided to subjects in the scenarios cannot account for the effects on probability estimates. Even when subjects are provided with identical information, the presentation of the information in scenario form and the requirement that subjects imagine the personal occurrence of the events cause significant differences in self-relevant probability estimates between the experimental and control conditions. We speculate that there are two plausible means by which scenario procedures like those of Carroll (1978) or of this study could lead to the heightened availability of an event and to a consequently biased probability estimate for it. First, a subject who has imagined an event's occurrence by following a highly structured scenario has been made to construct mental images of the event taking place. Because such images will thus become already formed, upon any subsequent consideration they may be more readily pictured than before. Second, an initial construction of an event as happening in a given fashion may create a cognitive "set" that impairs the ability to see the event in competing ways. A consequence may be a reduced capacity to picture the rival possibilities, making the first construction appear more true upon reflection. Further research designed to understand these processes must be undertaken. The final study also provides evidence that imagining a scenario can ultimately influence behavior, although intervening variables such as probability beliefs and attitudes (which are themselves influenced by the scenarios) undoubtedly play a mediating role. An additional question concerns the generality of the effects of scenarios on behaviors. For example, would people who have just been exposed to a scenario describing an automobile accident (and hence pre-
99
sumably believe that they are more likely to have an automobile accident) be more likely to engage in behaviors not specifically mentioned in the scenario but related to automobile safety, such as wearing seat belts? Certainly, situations exist for which behavior will not prove susceptible to influence through the use of scenarios, but Experiment 4 provides evidence that the scenario procedure can be a powerful behavioral-compliance technique. References Ajzen, I., & Fishbein, M. Understanding attitudes and predicting social behavior. Englewood Cliffs, N.J.: Prentice-Hall, 1980. Anderson, C. A., Lepper, M. R., & Ross, L. Perseverance of social theories: The role of explanation in the persistence of discredited information. Journal of Personality and Social Psychology, 1980, 39, 10371049. Aronson, E., & Carlsmith, J. M. Performance expectancy as a determinant of actual performance. Journal of Abnormal and Social Psychology, 1962, 65, 178-186. Bern, D. J. Self-perception theory. In L. Berkowitz (Ed.), Advances in experimental social psychology (Vol. 6). New York: Academic Press, 1972. Carroll, J. S. The effect of imagining an event on expectations for the event: An interpretation in terms of the availability heuristic. Journal of Experimental Social Psychology, 1978, 14, 88-96. Fishbein, M., & Ajzen, I. Belief, attitude, intention, and behavior. Reading, Mass.: Addison-Wesley, 1975. Gregory, W. L., Mowen, J. C., & Linder, D. E. Social psychology and plea bargaining: Applications, methodology, and theory. Journal of Personality and Social Psychology, 1978, 36, 1521-1530. Orne, M. T. On the social psychology of the psychology experiment: With particular reference to demand characteristics and their implications. American Psychologist, 1962, 17, 776-783. Sherman, S. J. On the self-erasing nature of errors of prediction. Journal of Personality and Social Psychology, 1980,59,211-221. Sherman, S. J., Skov, R. B., Hervitz, E. F., & Stock, C. B. Effects of explaining hypothetical future events: From possibility to probability to actuality and beyond. Journal of Experimental Social Psychology, 1981, 17, 142-158. Tversky, A., & Kahneman, D. Availability: A heuristic for judging frequency and probability. Cognitive Psychology, 1973, 5, 207-232. Weaver, D., & Brickman, P. Expectancy, feedback, and disconfirmation as independent factors in outcome satisfaction. Journal of Personality and Social Psychology, 1974, 30, 420-428.
Received September 21, 1981
