ttwntl »l Pinimttky ami Stckl
1976, Vol. 34, No. 1, J4-61
Fear Appeals r.nd Attitude Change: Effects of a Threat's
Noxiousness, Probability of Occurrence, and the
Efficacy of Coping Responses
Ronald W. Rogers and C. Ronald Mewborn University of South Carolina
Three factorial experiments examined the persuasive effects of the noxiousness of a threatened event, its probability of occurrence, and the efficacy of recom-mended protective measures. A total of 176 students participated in separate studies on the topics of cigarette smoking, driving safety, and venereal disease The results disclosed that increments in the efficacy variable increased inten-tions to adopt the recommended practices Interaction effects revealed that when the preventive practices were effective, increments in the noxiousness and probability variables facilitated attitude change; however, when the coping responses were ineffective, increments in noxiousness and probability either had no effect or a deleterious effect, respectively These interaction effects were discussed in terms of a defensive avoidance hypothesis, the crucial component of which was an inability to ward off the clanger. Furthermore, the effect of the emotion of fear upon intentions was found to be mediated by the cognitive appraisal of severity of the threat Finalh, similarities with and extensions of previous studies were reviewed
In one of the earliest theoretical analyses of fear arousal and persuasion (Hovland, Janis, & Kelley, 1953), fear appeals were characterized as communications describing the unfavorable consequences that might result from failure to adopt the communicator's recommendations. This definition was sufficiently sweeping to allow fear-arousing communications to be op-erationalized in a variety of ways. For ex-ample, fear has been manipulated in some studies by presenting information on the amount of bodily injury and the likelihood of exposure at each level of the manipulation (e.g., Chu, 1966), by omitting the latter in-formation at one level of the manipulation (e.g., Janis & Feshbach, 1953), and by omit-ting the latter information entirely (e.g., Rogers & Thistlethwaite, 1970). Investigators have been aware of different communication factors but have pursued other issues, not yet examining these factors systematically. If
This research was supported by Grant MH 22157 from the National Institute of Mental Health to the
first author
Requests for reprints should be sent to Ronald W. Rogers, who is now at the Department of Psychol-ogy, University of Alabama, University, Alabama 354«6.
fear-arousing communications are multifac-eted stimuli, then their persuasive impact may be due to any one or more of the components. Thus, the effective content stimuli that pro-duce attitude change may not have been firmly established.
If studies have varied different types of communication content, then it would be dif-ficult to compare experiments and to de-termine the communication variables produc-ing the theoretically relevant changes in at-titudes. We believe that conceptualizations of fear appeals have been too global and that they now must be refined if more precise and unequivocal relations are to be generated. An important conceptual and empirical task is to identify the effective content variables and their associated mediational processes. Therefore, the major purpose of the present series of three experiments was to investigate some of the more important components of a fear appeal.
Rogers (1975) has proposed that an ex-pectancy model, which includes all of the fac-tors of concern to investigafac-tors on fear com-munication and to workers with the health belief model (e.g., Hochbaum, 1958; Rosen-stock, 1974), be applied to the fear com-munication problem in a more systematic
anner. The three most crucial variables in a 'ar appeal are (a) the magnitude of noxious-ess of a depicted event, (b) the conditional robability that the event will occur provided o adaptive activity is performed, and (c) the ifectiveness of a coping response that might vert the noxious event. Several investigators ave recognized similar variables, among a ost of others, but the relationships among le components and the mediational processes iffer from those to be described subsequently, lost importantly, these communication vari-bles have not been simultaneously varied.
The noxiousness and probability content ariables may be derived from Hovland et al.'s 19S3) discussion of "potential dangers," and
he efficacy variable is very similar to their
>ncept of "reassurance." Limiting compo-ents of fear appeals to these three variables attractive not only because they seem to be ivotal concepts in Hovland et al.'s analysis ut also because this differentiation yields con-tructs similar to those in the more general Uegory of expectancy-value theories. Ac->rding to this class of theory, the tendency ) perform a particular act is a function of the xpectancy that the act will be followed by ertain consequences and the value of those onsequences. Feather (1959) identified psy-hologists in diverse areas who have used this /pe of theory (e.g., Lewin, 1938; Tolman, 932). Within the field of social psychology, xpectancy-value formulations have been ap-lied to the structure of attitudes (Rosenberg, 6), prediction of behavior from self-report leasures (Fishbein, 1967), and persuasion in le health education field (Hochbaum, 1958). iopefully, progress in understanding the fear immunication problem will be facilitated by theoretically based classification schema that linked to more general psychological
the-•ies.
Since the theory to be investigated, termed rotection motivation, has been presented in •'tail elsewhere (see Rogers, 1975), only the ost salient features are reviewed here. It is •sumed that each of the three components of
fear appeal initiates a corresponding cogni-ve mediating process. Each of these processes •praises communication information about i) noxiousness, (b) probability, or (c) effi-cy by placing each stimulus on dimensions
of (a) appraised severity of the depicted event, (b) expectancy of exposure to the event, or (c) belief in the efficacy of the rec-ommended coping response, respectively. It will be taken as a working hypothesis that these cognitive processes are independent. Each of these appraisal processes will be roughly proportional to the strength of the associated message variable. The representa-tion will not be exact, since individuals have different styles of appraising threatening events (cf. Lazarus, 1968).
It should be noted that appraised severity is a cognitive mediator distinct from fear. This position is similar to Leventhal's (1970) im-portant distinction between danger and fear control processes. There are several advan-tages of protection motivation theory's em-phasis upon cognitive mediational processes rather than an emotional state of fear that functions as an acquired drive. First, with respect to instrumental avoidance learning, Rescorla and Solomon (1967) suggested that peripheral physiological activity is merely an index of central states that mediate avoidance behavior. Second, protection from aversive events frequently requires long-sustained pro-cesses, like cognitive representations, rather than reflexive responsivity to visceral events. Third, the traditional association of fear with peripheral, visceral activity readily lends it-self to an emphasis upon reduction of the emotional state rather than avoidance of the environmental danger. Most importantly, as Leventhal noted, the fear appeal literature strongly suggests that cognitive processes are more important than emotional ones in medi-ating attitude change. Thus, protection mo-tivation theory might be viewed as differenti-ating Leventhal's "danger control" process into three cognitive mediational constructs specifically linked to antecedent communica-tion stimuli in a fear appeal.
RONALD W. ROGERS AND C. RONALD MEWBORN
other hypothesized effects. For each level of a magnitude of noxiousness variable, high probability of occurrence and high efficacy of coping response should each produce greater acceptance of the communicator's recom-mendation than low levels of these variables. Within a low-noxiousness condition, the su-periority of a high- over a low-efficacy condi-tion should be more pronounced in a high-than a low-probability condition. Within a high-noxiousness condition, the same order-ing of means should be found, but the dif-ferences should be more pronounced. There-fore, when acceptance of the communicator's recommendation is plotted against any one of the independent variables, the other two vari-ables should form a fan of diverging curves.
No experiments have been reported that attempted to investigate this triple-order in-teraction effect. The scant data that do bear upon other effects predicted by protection motivation theory provide moderate support (see Rogers, 1975). The purpose of the pres-ent series of experimpres-ents was to test the utility of protection motivation theory by factorially manipulating the three communication vari-ables and investigating their effects upon at-titudes toward health dangers that produce incalculable, yet preventable, human suffering: lung cancer, automobile injuries, and venereal disease.
METHOD
Design and Subjects
Separate experiments were performed on each of three health topics: cigarette smoking, safe driving,
and venereal diseases (gonorrhea and syphilis). Each
of the three experiments employed a 2 X 2 X 2 fac-torial design with three between-subjects manipula-tions: high versus low magnitude of noxiousness of the depicted event, high versus low probability of that event's occurrence, and high versus low ef-ficacy of recommended coping responses.
Subjects were 176 students enrolled in an ele-mentary psychology course who participated to satisfy a course requirement. Of those, 64 served in the venereal disease study, 72 in the driving study, and 40 in the smoking study. Students could only participate in one study Requirements for the three studies were as follows: For the smoking study, sub-jects had to have been smoking an average of at least 10 cigarettes per day for the past year. For the driving safety study, only subjects who had obtained a valid driver's license could participate. For the venereal disease study, participation was restricted to subjects who were not allergic to penicillin.
Procedure
Subjects were run in groups ranging from four t eight members, and each group was randomly a'. signed to one of the magnitude of noxiousness cor ditions. Within each of these conditions, each sti dent was randomly assigned to one of the probabilit of occurrence and efficacy of response condition Each experiment was presented as part of a proje< seeking college students' evaluations of public healtl programs. All subjects were cautioned that the might see films of bodily injury (or surgery) am were allowed to leave if they so desired. Only nin students left, and they were subsequently replaces In each experiment, the film manipulating tr noxiousness variable was shown first Each studei then underlined the key phrase in each paragraph « the experimentally varied probability of occurrem and efficacy of response written communication-The request to underline key phrases tended to ii sure that the essays were read and supported tt cover story that the materials were to be evaluated Finally, evaluation questionnaires, which containe the dependent variables to be described, were ac! ministered. After each session, students were thanke for their help and fully debriefed They were cau tioned that the essays were written for persuasiv purposes and then informed of the current state o knowledge regarding the independent variables. Mo importantly, all students were informed that th recommended preventive practices (e g, stoppini smoking) were extremely effective and were urgci to adopt them
Stimulus Materials
The high- and low-noxiousness movie sequence fo the smoking study was entitled "One in 20,000' Th low-noxiousness condition consisted of the first 1 minutes of the film. This portion depicts the ca.-. history of a man with lung cancer, portraying hi discovery of his condition, an interview with hi physician and a surgeon, and the surgical prepar; tions for removing his lung. The high-noxiousne film condition consisted of the same film plus a .' minute presentation of the operation for removing h lung
In the study on driving, the low-noxiousness filn was entitled "Broken Glass." This film depicts coi trolled collisions using remotely operated cars will anthropomctric dummies seated in them The higl noxiousness film, which was entitled "Wheels i Tragedy," portrays the gory aftermath of fatal col lisions For this film, a cameraman had traveled witl state highway patrolmen; thus, cars and victims wen shown before the arrival of ambulances and wrecker.
was entitled "Radical Retroperitoneal Node Dissec-tion in the Treatment of Testicular Tumors" and was loaned by the Armed Forces Institute of Pathol-ogy, Washington, D C. A 6-minute clip of this film depicts the surgical procedures used to remove dis-eased tissue from reproductive organs that had been destroyed by a venereal disease.
In each of the three experiments, the probability of occurrence and efficacy of response variables were manipulated by using written messages of approxi-mately equal length 1 Thus, subjects read a
com-munication arguing that the probability of being ex-posed to the threatened event was either high or low For example, in the smok-n;? study, the hi?h-proba-bility essay would present a persuasive case, supported by logical arguments and descriptive statistics, that if one smokes cigarettes, there is a very high chance of contracting lung cancer The low-probability essay would argue that although smoking can cause lung cancer, the chances of any given smoker actually developing cancer are very small. The high-efficacy essay would urge that the recommended preventive practices were extremely effective methods of avoid-ing the threatened event The low-efficacy message provided little reassurance that the available coping response was efficacious. Within each experiment, both efficacy messages would mention the same recommendations. The probability of occurrence es-say was always read before the efficacy of response essay.
Dependent Variables
A dependent measure of fear arousal, which was completed immediately after viewing the film and before reading the communications, consisted of six mood adjectives: fright, tension, nervousness, anx-iety, discomfort, and nausea. In each experiment, as manipulation checks, there were three items assessing the perceived severity of the depicted event (e.g., "Lung cancer is an extremely frightening and dan-gerous type of disease"), three items measuring ex-pectancy of exposure (e g , "I think it is likely that I will get lung cancer sometime in the years ahead"), and two items measuring the perceived efficacy of the recommended coVng responses (e.g , "For a snoker, giving up cigarettes is extremely effective in reducing the chances of developing lung cancer"). Four items were used in each study to assess intentions to comply with the recommended practices (see Foot-note 1) Examples of the intention items in the three experiments are as follows: "At the present time, I intend to stop smoking completely"; "When driving in the future, I shall always think ahead and plan ways I can avoid dangerous traffic situations"; and "I firmly intend to get penicillin treatments if I ever get a venereal disease " AH items were rated on 10-point graphic rating scales. Items were varied in the questionnaire so that on some of the state-ments a score of 10 represented complete agreement, while on others it represented complete disagreement. The latter items were converted in scoring responses so that higher numbers represented stronger
agree-ment. Scores on all dependent measures are baaed upon the mean ratings for the items in each duster.
RESULTS
The three experiments were included as a rsplications factor in the analysis of variance design. Thus, all dependent variables were analyzed i n a 2 x 2 x 2 x 3 design.
Manipulation Checks
Fear arousal. The analysis of the six mood
adjectives indicated that the high-noxiousness films produced higher levels of fear arousal than did the low-noxiousness films (Rs= 5.4 and 3.7, respectively),F(l, 152) = 6 4 . 6 2 , p < .0001. In addition, there was a main effect as-sociated with the replications factor, F(2,152) = 43.66, p < .0001. The mean fear score for the driving experiment (5.6) was higher than that for the smoking study (4.7), which, in turn, was higher than that for the venereal disease experiment (i.3).
Appraised severity. The films did not have
a significant effect on the measure of appraised severity, F(l, 152) = 2.18, p < .15. However, the high-probability essay (X = 7.7) pro-duced higher scores than the low-probability message (X = 7.0), F(\, 152) = 11.32, p < .001. There were no other significant main or interaction effects.
Expectancy of exposure. The probability of
occurrence communication was the only inde-pendent variable to affect expectancies of being exposed to the threatening events, F ( l , 152) = 37.14, p< .0001. The high-prob-ability essay produced higher mean scores (5.8) than did the low-probability message (4.5).
Belie) in efficacy of coping responses. The
groups exposed to the high-efficacy communi-cation believed the recommended practices to be more highly effective preventives than the groups who read the low-efficacy messages (#s = 8.3 and 4.5, respectively), F(l, 152) = 209.96, p< .0001. An Efficacy X Probability interaction effect, F(l, 152) = 6.96, p < .01, indicated that the efficacy variable's impact was more pronounced in the high-probability-of-occurrence condition than in the
58
RONALD W. ROGERS AND C. RONALD MEWBORNTABLE 1
MEAN SCORES ON THE MEASURE or INTENTIONS TO
ADOPT THE RECOMMENDED RESPONSES
Probability Experimental condition Low High
Low noxiousness Low efficacy High efficacy
High noxiousness Low efficacy High efficacy
5 9 6.1
5.6 6.7
55 6.8
5.8 7.1
ability-of-occurrence condition. Finally, there was a main effect associated with the noxious-ness manipulation, F(1, 152) = 4.69, p < .05, with the high-noxiousness mean of 6.7 higher than the low-noxiousness mean of 6.1.
Intent to Adopt Recommended Response
The predicted triple-order interaction effect was not obtained, F ( l , 152)= 1.37, p < .25. The obtained means are reported in Table 1. Compared with the low-efficacy condition (X = 5.7), the high-efficacy condition (X - 6.7) produced stronger intentions to accept the
6.5
6.0
5.5
5.0
4.5
4.0
i •
\
-f
HIGH EFFICACY >
s
LOW EFFICACY i LOW HIGH
PROBABILITY OF OCCURRENCE
FIGURE 1. Interaction effect of probability of oc-currence and efficacy of coping response upon intent
to adopt the recommended response in the cigarette smoking experiment.
7.5
7.0
6.3
6 0
5.5
HIGH EFFICACY
LOW EFFICACY o
LOW HIGH NOXIOUSNESS
FIOURE 2 Interaction effect of magnitude of nox-iousness and efficacy of coping response upon intent to adopt the recommended response in the venereal disease experiment.
preventive measures, F ( l , 152) = 13 23, p < 001). This main effect must be interpreted in light of the Efficacy X Probability X Replica-tions interaction effect, F(2,152) = 4.47, p < .02. The Efficacy x Probability interaction ef-fect was tested at each level of the Replica-tions factor. These analyses revealed that the second-order interaction attained significance only in the smoking experiment, F ( l , 32) = 5.87, p < .02. Figure 1 shows a plot of the obtained mean scores. Examination of this teraction revealed that it arose from the in-crease in the high-efficacy condition ( + 1.1) and the decrease in the low-efficacy condition ( — 1.5). There were no differences among the means in the other two studies.
Regression and Path Analyses
In many fear appeal studies (e.g., Leven-thal & Niles, 1964), supplementary correla-tional analyses, which ignore the classification variables, are performed to take advantage of the large individual differences in responses to the manipulations. Since protection motiva-tion theory assumes that the mediamotiva-tional pro-cesses are independent and directly affect in-tentions, an ordinary multiple linear regression equation was computed that entered the ma-nipulation check items as predictors of the criterion variable, intentions. Standardized co-efficients in such a multiple regression equa-tion can be interpreted as estimates of the contribution of predictor variables in "caus-ing" the criterion variable. Hence, this analy-sis might implicate a specific mediator(s) as being causally involved in determining inten-tions. The obtained standardized partial re-gression coefficients were as follows: for fear-arousal, .13; for severity, .19 (p < .OS); for expectancy of exposure, .03; and for belief in efficacy, .32 (p < .01). Thus, belief in the ef-ficacy of coping responses explained more of the variance than did any other predictor, and the appraised severity of the threatened event was the only other significant predictor.
The regression equation examined the sim-ple, direct effect of each mediator upon in-tentions. A path analysis was performed to examine a combination of simultaneous chain regressions (see Turner & Stevens, 19S9). Specifically, this analysis sought to determine whether the mediators operated upon inten-tions, not directly, but through one or more of the other mediators. Hence, in addition to the direct relationships indicated by the gression analysis, the path analysis might re-veal some causal cycles or paths. The paths that were significant beyond the .05 level are diagrammatically presented in Figure 3.
DISCUSSION
The hypothesized multiplicative relation-ship among the independent variables was re-jected. Nevertheless, the results of the present series of experiments demonstrated that incre-ments in the efficacy of recommended coping responses increased intentions to comply with the recommended practices. Regardless of what the threatened event was, or how noxious
FIGURE 3. Significant path coefficients among the dependent variables.
it was, or how likely it was to occur, the stronger the belief that a coping response could avert a danger, the more strongly people intended to adopt the communicator's recom-mendations. The main effect of the efficacy factor corroborates previous studies finding that this variable enhanced acceptance of medication (Chu, 1966), increased intentions to stop smoking (Rogers & Thistlethwaite, 1970), and reduced cigarette consumption (Rogers and Deckner, 1975). One practical implication is that mass media appeals should emphasize that their recommendations can ef-fectively control an aversive event. The sahi-tary effect of the efficacy of the recommenda-tions extends the findings of Leventhal and his colleagues (see Leventhal, 1970) that specific action instructions facilitate behavioral com-pliance. The data indicated that the efficacy component acted upon intentions, not by mak-ing the threat seem less severe or less likely to occur but by directly strengthening beliefs in the ability to cope with danger when it is con-fronted.
60 RONALD W. ROGERS AND C. RONALD MEWBORN
they indicated the degree of their acceptance of the communicator's recommendation. Mew-born also found that the film manipulation did not affect intentions. Although the present studies did not employ this continuous physio-logical monitoring, it seems reasonable to as-sume that the emotional arousal had dis-sipated by posttest time; thus, we would not expect emotional arousal to have affected in-tention scores. Furthermore, these studies and Leventhal's (1970) parallel response model suggest that the appraised severity of a threat should be distinguished from the transient emotional reaction to the threat. The path analysis of the present data demonstrated that fear arousal affected intentions, not directly, but by increasing the perceived severity of the threat, which, in turn, affected intentions. Protection motivation theory requires long-sustained cognitive representations (i.e., ap-praised severity) to mediate attitude change. Increments in the magnitude of noxiousness in the veneral disease study facilitated atti-tude change only if the recommended coping response was highly effective (see Figure 2). If the response was relatively ineffective, it did not matter how severe the danger was. This interaction effect is consistent with Janis and Feshbach's (19S3) defensive avoidance hypothesis. As elaborated by Rogers and Thistlethwaite (1970), this hypothesis sug-gests that "increments in fear-arousal should produce greater increments in acceptance of the recommended action when the audience is given high, rather than little or no, reassur-ance of the efficacy of the actions" (pp. 227-228). However, Rogers and Thistlethwaite found support for this interaction only on a subsidiary measure, the belief that cigarette smoking causes lung cancer. The present data provide stronger support, since they involve the more crucial measure of acceptance of the recommended preventive practices.
The interaction in the smoking experiment showed that increments in the probability variable tended to increase acceptance of the recommendation only if the recommendation was a highly effective preventive practice. If the recommendation was ineffective, incre-ments in probability of occurrence tended to have a boomerang effect. That is, if smokers were told that it was highly likely they could
contract lung cancer and that stopping smok ing would not improve their lot, they planned to increase their cigarette consumption. Leven-thai (1970) reviewed evidence indicating Leven-thai if an individual feels vulnerable to a threat, then resistances are aroused, and a boomerang effect is observed. The present findings sug gest that this may occur only when individual? feel incapable of coping with the threat; il they can cope, increasing the probability ol occurrence diminishes resistances and facili tates attitude change.
The interaction between the efficacy anc probability variables suggests an extension of the defensive avoidance hypothesis: It neec not be limited to an interaction involving feai or noxiousness. The key variable seems to be the inability to ward off a danger. Hence, re gardless of the magnitude of noxiousness of " threat, when expectancy of exposure to a threat is strongly aroused but not fully re-lieved by belief in the efficacy of the recom-mended coping response, individuals may re-sist the communicator's recommendation.
eople respond to threatening events with hich they cannot cope; in addition, fear ap-eal research may offer a method of experi-lentally inducing anxiety and stress by creat-ig beliefs in an inability to cope with a ireat.
In summary, this series of experiments con->lidated and extended previous findings. The ;lief in one's ability to ward off a danger rengthened intentions to adopt recommended reventive measures. Although protection mo-vation theory's hypothesized multiplicative jmbinatorial rule was rejected, the differen-ation of a fear communicdifferen-ation into three thogonal components proved to be impor-nt because the variables produced differeimpor-nt >rms of interaction effects on intentions to >mply with different health practices. Fur-lermore, the path analyses indicated that the feet of an emotional state of fear upon in-ntions was mediated by the cognitive ap-raisal of severity of the threat. These data )t only support Leventhal's separation of ar and danger control processes but empha-ze the relative importance of the latter, •otection motivation theory's cognitive medi-ional constructs of appraised severity and •lief in efficacy of coping response may be ewed as more specific components of Leven-ral's theoretical formulation. Hopefully, sys-•matic conceptual and empirical development additional communication, cognitive, and ispositional variables will extend the theory ir beyond its present circumspect terrain.
REFERENCES
>iu, C C Fear arousal, efficacy, and imminency
Journal of Personality and Social Psychology, 1966,
4, 517-524
ather, N. T Subjective probability and decision
under uncertainty. Psychological Review, 1959, 66,
150-164
shbein, M Attitude and the prediction of behavior.
In M. Fisnbein ( E d ) , Readings in attitude theory
and measurement. New York: Wiley, 1967.
ichbaum, G. Public participation in medical screen-ing programs: A soeiopsychological study (PHS
Publication No 572). Bethesda, Md.: United States Public Health Service, 1958
ovland, C , Janis, I , & Kelley, H Communication and persuasion. New Haven, Conn.: Yale Univer-sity Press, 1953.
nis, I. L , & Feshbach, S Effects of fear-arousing
communications. Journal of Abnormal and Social Psychology, 1953, 48, 78-92.
Lazarus, R. S. Emotions and adaptation: Conceptual and empirical relations. In W. Arnold (Ed.), Ne-braska Symposium on Motivation (Vol. 16). LiD-coln: University of Nebraska Press, 1968.
Lazarus, R. S , & Averill, J R. Emotion and cogni-tion- With special reference to anxiety. In C. D.
Spielberger (Ed.), Anxiety: Current trends in the-ory and research (Vol 2) New York: Academic
Press, 1972.
Leventhal, H. Findings and theory in the study of fear communications. In L. Berkowitz ( E d ) , Ad-vances in experimental social psychology (Vol. 5). New York- Academic Press, 1970.
Leventhal, H., & Niles, P. A field experiment on fear arousal with data on the validity of questionnaire
measures. Journal of Personality, 1964, 32, 459-479.
Leventhal, H., & Niles, P. Persistence of influence for varying durations of exposure to threat stimuli.
Psychological Reports, 1965, 16, 223-233.
Lewin, K. The conceptual representation and the measurement of psychological forces. Durham,
N C • Duke University Press, 1938.
Maier, S , Seligman, M., & Solomon, R. Pavlovian fear conditioning and learned helplessness. In B. Campbell & R. Church (Eds.), Punishment and aversive behavior. New York: Appleton-Century-Crofts, 1969.
McGrath, J. E. (Ed.) Social and psychological fac-tors in stress. New York: Holt, Rinehart &
Win-ston, 1970
Mewborn, C R Effects of threat and reassurance
upon attitude change Unpublished master's thesis, University of South Carolina, 1975.
Rescorla, R , & Solomon, R. L. Two-process learning theory. Relationships between Pavlovian condition-ing and instrumental learncondition-ing Psychological Re-view, 1967, 14, 151-182.
Rogers, R. W A protection motivation theory of fear appeals and attitude change. Journal of Psy-chology, 1975, 91, 93-114.
Rogers, R W , & Deckner, W. C. Effects of fear ap-peals and physiological arousal upon emotion, at-titudes, and cigarette smoking. Journal of
Per-sonality and Social Psychology, 1975, 32, 222-230.
Rogers, R. W., fc Thistlethwaite, D. L Effects of fear arousal and reassurance upon attitude change.
Journal of Personality and Social Psychology, 1970,
IS, 227-233.
Rosenberg, M. Cognitive structure and attitudinal af-fect. Journal of Abnormal and Social Psychology, 1956, 35, 362-372.
Rosenstock, I. Historical origins of the health be-lief model Health Education Monographs, 1974, 2, 328-335.
Tolman, E. C. Purposive behavior in animals and
men New York. Century, 1932.
Turner, M., & Stevens, C. The regression analysis of causal paths. Biometrics, 1959, IS, 236-258. s
