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Effects of race and exposure on judgments of interpersonal favorability
JOURNAL OF EXPERIMENTAL SOCIAL PSYCHOLOGY 11, 14-24 (1975)
Effects of Race and Exposure on Judgments of Interpersonal Favorabilityl NORMAN H . H A M M , M I C H A E L R . BAUM, AND K E N N E T H W . N I K E L S '~
University of Nebraska at Omaha Received August 14, 1973 T w o experiments replicated and extended the "mere exposure" effect across the variables of race, sex, and level of initial favorability. Both experiments employed a between subjects design in which white subjects rated their favorability toward 20 photographs, l0 of black and 10 of white college graduates. The initial exposure sequence was followed by l0 repetitions of each photograph for experimental subjects and an inverted alphabet printing task for control subjects. During the posttest all subjects again rated the photographs. Irrespective of race and sex of photograph or initial level of favorability, exposure functioned to enhance interpersonal attractiveness in both experiments.
Recently Zajonc (1968) has presented both correlational and experimental evidence which support the "mere exposure" hypothesis; that is, repeated presentations of a stimulus tend to enhance one's attitudes toward it. Offered as correlational evidence is the relationship of word frequency and affective value. Using 154 pairs of antonyms, Zajonc reported that the word judged most favorably was also the most frequently used word in 82% of the cases. Similarly, Johnson, Thomson, and Frincke (1960)found that words with positive affect have higher frequency counts than words with negative affect, and Strassburger and Wertheimer (1959) found that nonsense syllables high in association value were rated more pleasant by subjects than those of low association value. Other evidence has supported the "mere exposure effect" by directly manipulating the variable of stimulus repetition. Zajonc (I 968) systematically varied frequency of exposure and found enhanced attitudes for Turkish adjectives, Chinese characters, and photographs of college seniors. In the latter case, Zajonc presented 12 photographs at different frequencies (0, 1, 2, 5, 10, 25) and found in nine cases that higher J The present investigation was based upon two master's theses conducted at the University of Nebraska at Omaha by the second and third authors. The first author served as students' advisor. N o w at Kearney State College, Kearney, Nebraska. 14 Copyright (~) 1975 by Academic Press. Inc. Printed in the United States. All rights of reproductionin any form reserved.
INTERPERSONAL FAVORABILITY
15
frequencies generated increasingly positive affective ratings. While the defining conditions are still incompletely understood, the mere exposure effect has been replicated and extended in a variety of situations (Harrison, 1968a, 1969; Harrison and Zajonc, 1970; Zajonc and Rajecki, 1969). Relatively few laboratory and naturalistic investigations have addressed the problem of contact and race relations. A recent review by Amir (1969) stresses the importance of the situation in which contact occurs. Relying mostly on data from naturalistic studies, Amir claimed that favorable contacts tend to reduce prejudice, whereas unfavorable conditions often increase intergroup tensions. Several recent laboratory investigations appear consistent with Amir's view of exposure. Burgess and Sales (1971) and Perlman and Oskamp (1971) manipulated the context in which initially novel stimuli were presented; both studies found that stimuli presented in a positive context became more positive with exposure, while stimuli presented in a negative context tended to become more negative with exposure. Similar results were obtained by Brickman and Redfield (1970), but recent investigations by Zajonc and his associates (Seagert Swap, and Zajonc, 1973; Zajonc, Shaver, Travis, and Van Kreveld, 1972) reported that attraction increased in both positive and negative contexts as a function of exposure. Using abstract art as stimuli, Rosenblood and Ostrom (1971) reported an exposure effect for initially unfavorable stimuli, but not for initially favorable stimuli. In contrast to Zajonc's prediction, they found a significant convergence effect, with negative stimuli becoming more positive with exposure, while positive stimuli became more negative with exposure. Several conflicting theories have been offered to account for the overall exposure effect as well as the previously described context differences. Burgess and Sales (1971) account for their context differences with a simple explanation based on classical conditioning. They propose that the context of the stimulus situation become conditioned to the stimuli themselves and the strength of conditioning increases with increasing exposure. Hence, the exposure effect is explained by the positive affect of the experimental situation being associated with the exposed stimulus, while the conflicting Perlman and Oskamp (1971) results are explained by the negative context of the situation being increasingly conditioned to the stimuli. However, the association explanation cannot explain the Rosenblood and Ostrom (1971) results where initially negative stimuli became more positive, and initially positive stimuli became more negative. These authors concluded that adaptation is the better explanation of their results. Accordingly, with increasing exposure of a stimulus, its favorability value approaches a subjective neutral point. A third theoretical view of mere exposure stresses response competi-
16
HAMM, BAUM AND NIKELS
tion (Harrison, 1968b). A number of antagonistic response tendencies are produced by the appearance of a novel stimulus, and the tension state resulting from response competition is associated with negative affect. Further exposure to the stimulus reduces the response competition, and as one response tendency achieves dominance, a corresponding reduction of negative affect and attitudinal enhancement occurs. EXPERIMENT
I
Experiment I sought to replicate the "mere exposure effect" with a between subjects design and extend it to a situation in which male and female Caucasian subjects judge photographs of black and white individuals of both sexes. The primary concern of the experiment was whether exposure would serve to enhance attitudes equally for like- and different-race stimuli. METHOD Subjects Preexperimental subjects were 20 male and 20 female Caucasian introductory psychology volunteers at the University of Nebraska at Omaha. A similarly composed group of 40 males and 40 females participated in the exposure experiment titled "Visual Participation." Of this group, 20 students of each sex were randomly assigned to the experimental group and 20 to the control group.
Slides and Apparatus Subjects rated their favorability toward 20 college seniors, 10 white and 10 black, selected from a pool of 80 individuals taken from the 1970 Michigan State and University of Arkansas yearbooks. An 11-point, equal-interval rating scale was used to measure both pre- and postexposure attitudes toward the college graduates. The yearbook photographs were processed into 2 x 2 monochromatic slides for screen projection by a Kodak Carousel Slide Projector (Model 850). The stimulus exposure, interstimulus interval, and instructions were electronically controlled by a slide-tape synchronizer (Edmund Scientific Co.: Stock #41,222) and a stereo tape recorder (Wollensak 6200).
Experimental Design Slide selection. A preexperimental study was conducted to select the five most neutral slides for each sex by race category from a pool of 80 slides randomly selected from the yearbooks. The categories were white male, white female, black male, and black female. Forty preexperimental subjects rated each slide and final selection was based on two criteria: (a) the degree to which any slide approximated a neutral score of 6 on the 11-point favorability scale, (1-11), and (b) a discrepancy of less than 20 total points between male and female raters. The second criterion was employed to minimize the presence of any sex of rater effect in the subsequent exposure experiment. A series of t tests, comparing male and female favorability ratings of each slide, indicated the absence of significant sex differences. Experimental treatments. The effect of mere exposure on interpersonal favorabi!ity was
INTERPERSONAL FAVORABILITY
17
measured by a pre- to posttest change in subjects' ratings. Two groups, experimental (exposed) and control (nonexposed), were employed. In the pretest condition, both groups were exposed to each of the 20 slides for 2 sec, followed by a 5 sec interstimulus interval during which the subjects rated their favorability toward each slide on the 11-point scale. The order in which the slides were presented was randomly determined. After the pretest ratings, the experimental group was exposed to each individual photograph 10 times for a total of 200, 2 sec presentations. The exposure sequence was arranged such that each individual's slide occurred randomly once every 20 trials. The control group performed an inverted alphabet printing task during the period in which the experimental group received the exposure treatment. The slide sequence, interstimulus interval, and exposure duration used for the posttest were the same as used for the pretest.
Procedure Seven groups of approximately 12 subjects each rated the slide sequence. These groups were alternately given the experimental and control treatments. Instructions for the initial ratings were as follows. The purpose of this experiment is to study whether photographs can be used in forming impressions of people. You will view a number of slides of individuals, each presented for a 2 sec interval. After seeing a slide, you will have 5 sec to rate that person on an 11-point scale. Make your judgments about each person on the scale from unfavorable to favorable. Your judgments should be made on the basis of how much the person appeals to you or how pleasing he or she seems. Scale usage was then explained in detail. The instructions for the experimental treatment were. "Now view these slides without rating them." The control group was given instructions for the inverted alphabet printing task (see (Jung and Bailey, 1966)). For the posttest condition, all subjects were told, "Now rate these slides." After the postratings, all subjects responded to a demand-characteristics questionnaire (see (Orne, 1962)). The experimental group subjects were asked first. "Describe what you think the experimenter was trying to accomplish by asking you to print in alphabetical order the letters of the alphabet in an inverted or upside-down arrangement?" All subjects were then questioned. "What do you think was the purpose of this experiment?"
RESULTS The ratings of favorability for the five slides which composed each race by sex category were summed separately for the pre- and posttests. Two separate repeated measures analyses of variance were performed o n t h e t o t a l e d f a v o r a b i l i t y s c o r e s . T h e first w a s a 2 ( T r e a t m e n t ) × 2 ( S e x of Rater) × 2 (Race) × 2 (Sex of Slide) analysis on the pretest ratings. T h e a n a l y s i s w a s p e r f o r m e d to r e v e a l d i f f e r e n c e s in t h e p e r c e p t i o n o f black and white male and female slides by Caucasian subjects. Second, a 2 (Treatment) × 2 (Sex of Rater) × 2 (Test) × 2 (Race of Slide) × 2 (Sex of Slide) repeated measures analysis was conducted on the subjects' favorability ratings for both the pre- and posttests to examine possible d i f f e r e n c e s in e x p o s u r e r e l a t e d to s e x o f s u b j e c t , r a c e , a n d s e x Of slide.
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HAMM, BAUM AND NIKELS
Pretest Analysis Sex o f slide. T h e main effect o f sex o f slide was significant (F(1,76) = 38.83, p < .01). The mean favorability rating for female slides was 34.01, for male slides, 31.15. Sex o f rater × sex o f slide. This interaction indicated a larger sex of slide effect f o r m a l e raters than female raters (F(1,76) = 7.70,p < .01 ). A simple effects analysis revealed that, while female slides of both races were not rated differently by the sexes, females rated male slides significantly more favorably than male subjects (F(1,76) = 15.02, p < .001). Sex o f rater x race of slide. T h e analysis of the interaction of sex of rater and race of slide was significant (F(1,76) = 5.45, p < .05). Inspection of the cell means indicated larger differences due to sex of rater for black slides than for white slides. H o w e v e r , a simple main effects analysis revealed an absence of further statistically reliable differences. Race of slide x sex of s#de. T h e F value for the race by sex of slide interaction was significant ( F ( 1 , 7 6 ) = 17.57, p < .01). Inspection of the data revealed the presence of a smaller sex effect for black slides than for white slides. Additionally, a simple main effects analysis revealed no significant sex effect for black slides. H o w e v e r , the significant interaction probably represents a type I error since subjects were randomly assigned to treatment groups (see (Rosnow and Suls, 1970)). In any case, since these same three factors were not found to interact significantly with the exposure treatment, as cited below in the exposure analysis, this did not constitute a potential source of bias in evaluating the exposure effect. N o other main effects or interactions were found to be significant in the pretest analysis. Exposure Analysis Sex ofs6de. As in the pretest analysis, female slides were rated more favorably than male slides ( F ( 1 , 7 6 ) = 55.20, p < .001). H o w e v e r , little information, above that provided by the pretest analysis, is presented by the main effect of sex since it may be confounded by a potential exposure effect present in the posttest measure. Treatment × test. Figure 1 presents the mean favorability scores for both treatments on the pre- and posttests. The analysis yielded a significant interaction (F(1,76) = 7.28, p < .01). Inspection of Fig. 1 indicates that exposure served to enhance the attitudes of the experimental group, while the interpolated activity of inverted alphabet printing resulted in a slight decrease in favorability ratings from the pre- to posttest for the control group. A simple main effects analysis revealed a significant increase in ratings of favorability from the pre- to the posttests for the
INTERPERSONAL FAVORABILITY
-
~35
19
- Experimental Group
,,---,,, Control Group
.m 3 4
2 o 33 ,- 3 2
!
!
Pre
Post Test
FIG. 1. M e a n favorability rating as a function o f exposure across tests (Experiment 1).
experimental group (F(1,76) = 4.48, p < .05). The decrease in favorability from pre- to posttest for the control group was not significant (F(1,76) = 2.91,p > .10). No additional main effects or interactions relating to the exposure condition were found to be statistically reliable.
Demand-Characteristics Questionnaire A content analysis was performed on the responses made by both treatment groups to the second question. The response categories of attitude change, first impressions, and true feelings, including amount remembered, and personal appeal toward the slides, were then collapsed across both groups. A Binomial Test comparing the observed response frequencies of the experimental and control group was not statistically significant (z = .802, p > .05), indicating the absence of differential demand characteristics for both treatments.
EXPERIMENT II Experiment II dealt with race and level of initial interpersonal favorability. Previously, Perlman and Oskamp (I 971) reported that when black and white photographs were presented in positive, neutral, and negative settings, blacks displayed a smaller effect of positive exposure and a greater effect of negative context than whites.
METHOD
Subjects Preexperimental subjects were 20 white male volunteers enrolled in an introductory psychology class at the University of N e b r a s k a at O m a h a . A similar sample of 50 males, 25 each for the experimental and control groups, served as subjects for the exposure experiment. Participation was voluntary.
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HAMM, BAUM AND NIKELS
Apparatus Apparatus was the same as in Experiment I, except 50 monochromatic 2 x 2 slides were taken from recent Hiram Scott College (Scottsbluff, Nebraska) yearbooks.
Experimental Design and Procedure Preexperimentalprocedure. A preexperimental study was conducted to select five positive and five negative photographs for each racial group. Ratings were made on a pool of 25 black and 25 white male slides, each preselected for high or low favorability. Since black slides were not judged as extreme as whites, the five most negative and five most positive black photographs were chosen and matched with slides of whites. Accordingly, the two most negative and the most positive white slides were not included in the experimental sequence because of their extreme ratings. The mean ratings for the low and high black and white groups were 4.15, 7.70, 4.22, and 7.56, respectively. Two t tests compared the mean black and white ratings for each favorability category; both t values were found to be nonsignificant (p > .05). Experimental design. The general experimental design was the same as Experiment I, except the sex of slide and sex of rater variables were excluded from consideration and the factor of initial affective favorability added. Also, instead of a completely randomized preand posttest slide sequence, slides were randomly presented with the restriction that every four trials were balanced for the variables of race and initial favorability. Procedure. There were three somewhat minor differences between the procedures used in Experiments I and II. First, a 4 sec intertrial interval was used for subjects to make their pre- and posttest ratings. Second, eight groups, averaging six subjects were alternately assigned to the experimental (exposure) and control (nonexposure) conditions. Finally no "demand characteristics" questions were used at the end of the experiment.
RESULTS T h e five ratings for e a c h race b y f a v o r a b i l i t y c a t e g o r y were t o t a l e d for each s u b j e c t in c a l c u l a t i n g the d e p e n d e n t m e a s u r e . A s in E x p e r i m e n t I, two r e p e a t e d m e a s u r e s a n a l y s e s o f v a r i a n c e were c o m p u t e d to e v a l u a t e s e p a r a t e l y differences in p r e t e s t ratings a n d a n y c h a n g e s p r o d u c e d b y mere exposure. The former analysis consisted of a 2 ( t r e a t m e n t ) × 2 (race) x 2 (initial f a v o r a b i l i t y ) a n a l y s i s of v a r i a n c e of the p r e t e s t measure, while the latter c o n s t i t u t e d a 2 ( t r e a t m e n t ) x 2 (tests) × 2 (race) x 2 (initial f a v o r a b i l i t y ) a n a l y s i s o n both the pre- a n d p o s t t e s t data.
Pretest Analysis Initialfavorability. T h e p r e t e s t a n a l y s i s r e v e a l e d a significant m a i n effect for the f a v o r a b i l i t y c a t e g o r y (p < .001). H e n c e , the effect represents a cross v a l i d a t i o n of the f a v o r a b i l i t y categories with a different s a m p l e o f s u b j e c t s t h a n u s e d in the p r e e x p e r i m e n t a l p r o c e d u r e . Treatment × race × initial favorability. T h i s triple o r d e r i n t e r a c t i o n y i e l d e d a significant effect ( F ( l , 4 8 ) = 6.39, p < .025). I n s p e c t i o n o f the cell m e a n s r e v e a l e d that the low f a v o r a b i l i t y white slides w e r e rated l o w e r t h a n the low f a v o r a b i l i t y b l a c k slides for the e x p e r i m e n t a l group. C o n v e r s e l y , for the c o n t r o l g r o u p , the low f a v o r a b i l i t y b l a c k slides were
21
INTERPERSONAL FAVORABILITY A.LOW FAVORABILITY 50 29 28 27 26
o---OEXPERIMENTAL GROUP I - - - . I C O N T R O L GROUP
24 ~ 25
B . H ~ H FAVORABILtTY 45 42 41 40 39
/
e
38 37 36' 35
23 22 21 20
34 33' i PRE
l POST
<
t PRE
I POST
TEST
FIG. 2. M e a n favorability rating as a function of e x p o s u r e and initial affective value across tests (Experiment Il).
rated lower than the white slides. However, since each small group was alternately assigned to each treatment group, this triple-order interaction probably represents an alpha error. Exposure Analysis T r e a t m e n t x tests. As in Experiment I, it is evident that the experimental group, which received the exposure condition, exhibited a larger pre- to posttest increase in affective ratings than did the control group (F(1,48) = 42.64, p < .001). A simple main effects analysis revealed that the judged favorability increased from pre- to posttest for the experimental group (F(1,24)= 25.72, p < .001), while no significant change occurred for the control group. T r e a t m e n t x initial favorability x tests. Convergence across tests did not take place for the high- and low-favorability categories. Figure 2 presents graphically the nonsignificant interaction (F(1,48) = 3.13, p > .10). As graph A of Fig. 2 indicates, an increase in favorability as a function of exposure was found for the slides initially rated as low in favorability. However, as graph B illustrates, exposure also produced an increase in affective rating for the high favorability slides, a result contrary to the convergence hypothesis. No other interaction effect relating to the exposure treatment was found to be significant.
DISCUSSION Experiment I
The significant overall T r e a t m e n t x Test interaction and subsequent simple main effects analyses indicated that exposure served to enhance
22
HAMM, BAUM A N D NIKELS
interpersonal favorability for experimental subjects, while no significant change in favorability occurred for the control (unexposed) subjects. Such results replicate Zajonc's (1968) "mere exposure effect" using photographs of human faces, as well as other laboratory studies dealing with exposure (Harrison, 1969; Johnson, Thomson, and Fincke, 1960; Perlman and Oskamp, 1971), and provides one of the few demonstrations of the effect with a between group design. Little can be said about the substantial, but nevertheless nonsignificant, decrease in the control group's favorability ratings from the pre- to posttest since no similar change occurred for the control group in Experiment II. Also, the significant interactions involving the treatment variable for the pretest results in both experiments are difficult to explain. They can only represent either two type I errors, or the presence of some unknown sampling bias. In addition to replicating the "mere exposure effect," analysis of the pretest favorability scores revealed the presence of several interesting interactions regarding the importance of sex and race in the impression formation process. However, little can be learned about real-life racism since no comparable sample of black subjects was included in the experiment and subjects evaluated pictures of individuals rather than the individuals themselves. Despite these limitations, future research should be done to assess the generalizability of the present laboratory findings. Experiment I I
As in Experiment I, the significant Treatments x Tests interaction replicated and extended the "mere exposure effect" across the variables of race and initial level of favorability. Hence, exposure to an integrated slide sequence was a sufficient condition for the enhancement of interpersonal attraction. Unlike Experiment I, only a slight decrease was observed across tests for the control group. From Rosenblood and Ostrom's (1971 ) study, it was expected that the ratings for the favorability categories would converge across tests. Such a prediction is consistent with an adaptation level theory of mere exposure. However, the results of the present experiment appear inconsistent with both the adaptation and association (classical conditioning) views of mere exposure. Regarding the latter, the negative affect associated with slides of low favorability would be expected to produce a decrease in liking as a function of exposure. Obviously, the opposite was found. The general response competition view represents the only theoretical orientation consistent with the present experimental results. Empirically speaking, the results of the present study may not be inconsistent with the earlier Rosenblood and Ostrom (1971) investigation. Inspection of their data reveals that a slight increase in favorability took
INTERPERSONAL FAVORABILITY
23
place for art pieces judged highly attractive. It was only after 20 exposures that a significant convergence in ratings occurred. Another important difference between the studies concerns the relative distinctiveness of categories. On a 7-point scale, they reported mean ratings of 2.55 for low favorability objects and 5.13 for high favorability objects. These means indicated that they used favorability categories which were more extreme than in the present study. Finally, human faces are certainly different from abstract art, and it is quite possible that exposure may produce a different effect for each type of stimulus. Indeed, like the present investigation, a recent study reported by Saegert, Swap, and Zajonc (1973) found that interpersonal attraction increased as a positive function of number of encounters, regardless of the situational context. Finally, the fact that Burgess and Sales (1971), Perlman and Oskamp (1971) and the present study varied the inherent attractiveness of the object may account for the difference in results. R a c e and M e r e Exposure
Perhaps the most important result of Experiments I and 1I was the absence of significant Treatment x Tests x R a c e interactions. Regardless of race of slide, therefore, exposure served to enhance the interpersonal attractiveness of both black and white individuals. The context of the social interaction may reveal racial differences, as recently reported by Perlman and Oskamp (1971). They presented black and white individuals in positive, neutral, and negative behavioral settings to their subjects. They found that positive behavior contexts enhanced attitudes while negative contexts decreased attitudes. However, black photographs displayed a smaller effect of positive exposure and a larger effect of negative exposure than white individuals. Generalizing the results of the present study to real-life interaction or integration must be made with extreme caution (see (Amir, 1969)). However, despite the potential importance of social context, the present study might suggest that nominal exposure to blacks might be sufficient condition for attitudinal enhancement on the part of white Americans. Future research should seek to evaluate the generalizability of the present laboratory results to real-life integrated situations.
REFERENCES AMIR, Y. Contact hypothesis in ethnic relations. Psycholoq, ical Bulletin, 1969, 71, 319-342. BRICKMAN, P., & REDFIELD, J. Drive and predisposition as factors in the attitudinal effects of mere exposure. Paper presented at the meeting of American Psychological Association, Miami Beach, September 1970. BURGESS, T. D. G., II, & SALES, S. M. Attitudinal effects of mere exposure: A re-evaluation. Journal of Experimental Social Psychology, 1971, 7, 461-472.
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HARRISON, A. A. Exposure, favorability, and item endorsement. Psychological Reports, 1968, 23, 1070. (a) HARRISON, A. A. Response competition, frequency, exploratory behavior, and liking. Journal of Personality and Social Psychology, 1968, 9, 363-368, (b) HARRISON, A. A. Exposure and popularity. Journal of Personality, 1969, 37, 359-377. HARRISON, A. A., & ZAJONC, R. B. The effects of frequency and duration of exposure on response competition and affective ratings. Journal of Psychology, 1970, 75, 163-169. JOHNSON, R. C., THOMSON, C. W., & FINCKE, G. Word values, word frequency, and visual duration thresholds. Psychological Review, 1960, 67, 332-342. JUNG, J., & BAILEY, J. Contemporary Psychology Experiments: Adaptations for the Laboratory. New York: Wiley, 1966. ORNE, M. T. On the social psychology of the psychological experiment: With particular reference to demand characteristics and their implications. American Psychologist, 1962, 12, 776-783. PERLMAN, D., & OSKAMP, S. The effects of picture content and exposure frequency on evaluations of Negroes and whites. Journal of Experimental Social Psychology, 1971, 7, 503-514. ROSENBLOOD, L., & OSTROM, T. M. Is "mere exposure" merely adaptation? Paper presented at the Midwestern Psychological Association, Detroit, May 1971. ROSNOW, R. L., & SULS, J. M. Reactive effects of pretesting in attitude research. Journal of Personality and Social Psychology, 1970, 15, 338-343. SAEGERT, S., SWAP, W., & ZAJONC, R. B. Exposure, context, and interpersonal attraction. Journal of Persona6ty and Social Psychology, 1973, 25, 234-242. STRASSBURGER,F., & WERTHEIMER, M. The discrepancy hypothesis of affect and association value of nonsense syllables. Psychological Reports, 1959, 5, 528. ZAJONC, R. B. Attitudinal effects of mere exposure. Journal of Personality and Social Psychology, 1968, 9 (2, part 2), 1-27. ZAJONC, R. B. & RAJECKI, D. W. Exposure and affect: A field experiment. Psychonomic Science, 1969, 17, 216-217. ZA~ONC, R. B., SHAVER, P., TRAVIS, C., & VAN KREVELD, D. Exposure, satiation, and discrimination. Journal of Personality and Social Psychology, 1972, 21, 270-280.
Effects of Race and Exposure on Judgments of Interpersonal Favorabilityl NORMAN H . H A M M , M I C H A E L R . BAUM, AND K E N N E T H W . N I K E L S '~
University of Nebraska at Omaha Received August 14, 1973 T w o experiments replicated and extended the "mere exposure" effect across the variables of race, sex, and level of initial favorability. Both experiments employed a between subjects design in which white subjects rated their favorability toward 20 photographs, l0 of black and 10 of white college graduates. The initial exposure sequence was followed by l0 repetitions of each photograph for experimental subjects and an inverted alphabet printing task for control subjects. During the posttest all subjects again rated the photographs. Irrespective of race and sex of photograph or initial level of favorability, exposure functioned to enhance interpersonal attractiveness in both experiments.
Recently Zajonc (1968) has presented both correlational and experimental evidence which support the "mere exposure" hypothesis; that is, repeated presentations of a stimulus tend to enhance one's attitudes toward it. Offered as correlational evidence is the relationship of word frequency and affective value. Using 154 pairs of antonyms, Zajonc reported that the word judged most favorably was also the most frequently used word in 82% of the cases. Similarly, Johnson, Thomson, and Frincke (1960)found that words with positive affect have higher frequency counts than words with negative affect, and Strassburger and Wertheimer (1959) found that nonsense syllables high in association value were rated more pleasant by subjects than those of low association value. Other evidence has supported the "mere exposure effect" by directly manipulating the variable of stimulus repetition. Zajonc (I 968) systematically varied frequency of exposure and found enhanced attitudes for Turkish adjectives, Chinese characters, and photographs of college seniors. In the latter case, Zajonc presented 12 photographs at different frequencies (0, 1, 2, 5, 10, 25) and found in nine cases that higher J The present investigation was based upon two master's theses conducted at the University of Nebraska at Omaha by the second and third authors. The first author served as students' advisor. N o w at Kearney State College, Kearney, Nebraska. 14 Copyright (~) 1975 by Academic Press. Inc. Printed in the United States. All rights of reproductionin any form reserved.
INTERPERSONAL FAVORABILITY
15
frequencies generated increasingly positive affective ratings. While the defining conditions are still incompletely understood, the mere exposure effect has been replicated and extended in a variety of situations (Harrison, 1968a, 1969; Harrison and Zajonc, 1970; Zajonc and Rajecki, 1969). Relatively few laboratory and naturalistic investigations have addressed the problem of contact and race relations. A recent review by Amir (1969) stresses the importance of the situation in which contact occurs. Relying mostly on data from naturalistic studies, Amir claimed that favorable contacts tend to reduce prejudice, whereas unfavorable conditions often increase intergroup tensions. Several recent laboratory investigations appear consistent with Amir's view of exposure. Burgess and Sales (1971) and Perlman and Oskamp (1971) manipulated the context in which initially novel stimuli were presented; both studies found that stimuli presented in a positive context became more positive with exposure, while stimuli presented in a negative context tended to become more negative with exposure. Similar results were obtained by Brickman and Redfield (1970), but recent investigations by Zajonc and his associates (Seagert Swap, and Zajonc, 1973; Zajonc, Shaver, Travis, and Van Kreveld, 1972) reported that attraction increased in both positive and negative contexts as a function of exposure. Using abstract art as stimuli, Rosenblood and Ostrom (1971) reported an exposure effect for initially unfavorable stimuli, but not for initially favorable stimuli. In contrast to Zajonc's prediction, they found a significant convergence effect, with negative stimuli becoming more positive with exposure, while positive stimuli became more negative with exposure. Several conflicting theories have been offered to account for the overall exposure effect as well as the previously described context differences. Burgess and Sales (1971) account for their context differences with a simple explanation based on classical conditioning. They propose that the context of the stimulus situation become conditioned to the stimuli themselves and the strength of conditioning increases with increasing exposure. Hence, the exposure effect is explained by the positive affect of the experimental situation being associated with the exposed stimulus, while the conflicting Perlman and Oskamp (1971) results are explained by the negative context of the situation being increasingly conditioned to the stimuli. However, the association explanation cannot explain the Rosenblood and Ostrom (1971) results where initially negative stimuli became more positive, and initially positive stimuli became more negative. These authors concluded that adaptation is the better explanation of their results. Accordingly, with increasing exposure of a stimulus, its favorability value approaches a subjective neutral point. A third theoretical view of mere exposure stresses response competi-
16
HAMM, BAUM AND NIKELS
tion (Harrison, 1968b). A number of antagonistic response tendencies are produced by the appearance of a novel stimulus, and the tension state resulting from response competition is associated with negative affect. Further exposure to the stimulus reduces the response competition, and as one response tendency achieves dominance, a corresponding reduction of negative affect and attitudinal enhancement occurs. EXPERIMENT
I
Experiment I sought to replicate the "mere exposure effect" with a between subjects design and extend it to a situation in which male and female Caucasian subjects judge photographs of black and white individuals of both sexes. The primary concern of the experiment was whether exposure would serve to enhance attitudes equally for like- and different-race stimuli. METHOD Subjects Preexperimental subjects were 20 male and 20 female Caucasian introductory psychology volunteers at the University of Nebraska at Omaha. A similarly composed group of 40 males and 40 females participated in the exposure experiment titled "Visual Participation." Of this group, 20 students of each sex were randomly assigned to the experimental group and 20 to the control group.
Slides and Apparatus Subjects rated their favorability toward 20 college seniors, 10 white and 10 black, selected from a pool of 80 individuals taken from the 1970 Michigan State and University of Arkansas yearbooks. An 11-point, equal-interval rating scale was used to measure both pre- and postexposure attitudes toward the college graduates. The yearbook photographs were processed into 2 x 2 monochromatic slides for screen projection by a Kodak Carousel Slide Projector (Model 850). The stimulus exposure, interstimulus interval, and instructions were electronically controlled by a slide-tape synchronizer (Edmund Scientific Co.: Stock #41,222) and a stereo tape recorder (Wollensak 6200).
Experimental Design Slide selection. A preexperimental study was conducted to select the five most neutral slides for each sex by race category from a pool of 80 slides randomly selected from the yearbooks. The categories were white male, white female, black male, and black female. Forty preexperimental subjects rated each slide and final selection was based on two criteria: (a) the degree to which any slide approximated a neutral score of 6 on the 11-point favorability scale, (1-11), and (b) a discrepancy of less than 20 total points between male and female raters. The second criterion was employed to minimize the presence of any sex of rater effect in the subsequent exposure experiment. A series of t tests, comparing male and female favorability ratings of each slide, indicated the absence of significant sex differences. Experimental treatments. The effect of mere exposure on interpersonal favorabi!ity was
INTERPERSONAL FAVORABILITY
17
measured by a pre- to posttest change in subjects' ratings. Two groups, experimental (exposed) and control (nonexposed), were employed. In the pretest condition, both groups were exposed to each of the 20 slides for 2 sec, followed by a 5 sec interstimulus interval during which the subjects rated their favorability toward each slide on the 11-point scale. The order in which the slides were presented was randomly determined. After the pretest ratings, the experimental group was exposed to each individual photograph 10 times for a total of 200, 2 sec presentations. The exposure sequence was arranged such that each individual's slide occurred randomly once every 20 trials. The control group performed an inverted alphabet printing task during the period in which the experimental group received the exposure treatment. The slide sequence, interstimulus interval, and exposure duration used for the posttest were the same as used for the pretest.
Procedure Seven groups of approximately 12 subjects each rated the slide sequence. These groups were alternately given the experimental and control treatments. Instructions for the initial ratings were as follows. The purpose of this experiment is to study whether photographs can be used in forming impressions of people. You will view a number of slides of individuals, each presented for a 2 sec interval. After seeing a slide, you will have 5 sec to rate that person on an 11-point scale. Make your judgments about each person on the scale from unfavorable to favorable. Your judgments should be made on the basis of how much the person appeals to you or how pleasing he or she seems. Scale usage was then explained in detail. The instructions for the experimental treatment were. "Now view these slides without rating them." The control group was given instructions for the inverted alphabet printing task (see (Jung and Bailey, 1966)). For the posttest condition, all subjects were told, "Now rate these slides." After the postratings, all subjects responded to a demand-characteristics questionnaire (see (Orne, 1962)). The experimental group subjects were asked first. "Describe what you think the experimenter was trying to accomplish by asking you to print in alphabetical order the letters of the alphabet in an inverted or upside-down arrangement?" All subjects were then questioned. "What do you think was the purpose of this experiment?"
RESULTS The ratings of favorability for the five slides which composed each race by sex category were summed separately for the pre- and posttests. Two separate repeated measures analyses of variance were performed o n t h e t o t a l e d f a v o r a b i l i t y s c o r e s . T h e first w a s a 2 ( T r e a t m e n t ) × 2 ( S e x of Rater) × 2 (Race) × 2 (Sex of Slide) analysis on the pretest ratings. T h e a n a l y s i s w a s p e r f o r m e d to r e v e a l d i f f e r e n c e s in t h e p e r c e p t i o n o f black and white male and female slides by Caucasian subjects. Second, a 2 (Treatment) × 2 (Sex of Rater) × 2 (Test) × 2 (Race of Slide) × 2 (Sex of Slide) repeated measures analysis was conducted on the subjects' favorability ratings for both the pre- and posttests to examine possible d i f f e r e n c e s in e x p o s u r e r e l a t e d to s e x o f s u b j e c t , r a c e , a n d s e x Of slide.
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HAMM, BAUM AND NIKELS
Pretest Analysis Sex o f slide. T h e main effect o f sex o f slide was significant (F(1,76) = 38.83, p < .01). The mean favorability rating for female slides was 34.01, for male slides, 31.15. Sex o f rater × sex o f slide. This interaction indicated a larger sex of slide effect f o r m a l e raters than female raters (F(1,76) = 7.70,p < .01 ). A simple effects analysis revealed that, while female slides of both races were not rated differently by the sexes, females rated male slides significantly more favorably than male subjects (F(1,76) = 15.02, p < .001). Sex o f rater x race of slide. T h e analysis of the interaction of sex of rater and race of slide was significant (F(1,76) = 5.45, p < .05). Inspection of the cell means indicated larger differences due to sex of rater for black slides than for white slides. H o w e v e r , a simple main effects analysis revealed an absence of further statistically reliable differences. Race of slide x sex of s#de. T h e F value for the race by sex of slide interaction was significant ( F ( 1 , 7 6 ) = 17.57, p < .01). Inspection of the data revealed the presence of a smaller sex effect for black slides than for white slides. Additionally, a simple main effects analysis revealed no significant sex effect for black slides. H o w e v e r , the significant interaction probably represents a type I error since subjects were randomly assigned to treatment groups (see (Rosnow and Suls, 1970)). In any case, since these same three factors were not found to interact significantly with the exposure treatment, as cited below in the exposure analysis, this did not constitute a potential source of bias in evaluating the exposure effect. N o other main effects or interactions were found to be significant in the pretest analysis. Exposure Analysis Sex ofs6de. As in the pretest analysis, female slides were rated more favorably than male slides ( F ( 1 , 7 6 ) = 55.20, p < .001). H o w e v e r , little information, above that provided by the pretest analysis, is presented by the main effect of sex since it may be confounded by a potential exposure effect present in the posttest measure. Treatment × test. Figure 1 presents the mean favorability scores for both treatments on the pre- and posttests. The analysis yielded a significant interaction (F(1,76) = 7.28, p < .01). Inspection of Fig. 1 indicates that exposure served to enhance the attitudes of the experimental group, while the interpolated activity of inverted alphabet printing resulted in a slight decrease in favorability ratings from the pre- to posttest for the control group. A simple main effects analysis revealed a significant increase in ratings of favorability from the pre- to the posttests for the
INTERPERSONAL FAVORABILITY
-
~35
19
- Experimental Group
,,---,,, Control Group
.m 3 4
2 o 33 ,- 3 2
!
!
Pre
Post Test
FIG. 1. M e a n favorability rating as a function o f exposure across tests (Experiment 1).
experimental group (F(1,76) = 4.48, p < .05). The decrease in favorability from pre- to posttest for the control group was not significant (F(1,76) = 2.91,p > .10). No additional main effects or interactions relating to the exposure condition were found to be statistically reliable.
Demand-Characteristics Questionnaire A content analysis was performed on the responses made by both treatment groups to the second question. The response categories of attitude change, first impressions, and true feelings, including amount remembered, and personal appeal toward the slides, were then collapsed across both groups. A Binomial Test comparing the observed response frequencies of the experimental and control group was not statistically significant (z = .802, p > .05), indicating the absence of differential demand characteristics for both treatments.
EXPERIMENT II Experiment II dealt with race and level of initial interpersonal favorability. Previously, Perlman and Oskamp (I 971) reported that when black and white photographs were presented in positive, neutral, and negative settings, blacks displayed a smaller effect of positive exposure and a greater effect of negative context than whites.
METHOD
Subjects Preexperimental subjects were 20 white male volunteers enrolled in an introductory psychology class at the University of N e b r a s k a at O m a h a . A similar sample of 50 males, 25 each for the experimental and control groups, served as subjects for the exposure experiment. Participation was voluntary.
20
HAMM, BAUM AND NIKELS
Apparatus Apparatus was the same as in Experiment I, except 50 monochromatic 2 x 2 slides were taken from recent Hiram Scott College (Scottsbluff, Nebraska) yearbooks.
Experimental Design and Procedure Preexperimentalprocedure. A preexperimental study was conducted to select five positive and five negative photographs for each racial group. Ratings were made on a pool of 25 black and 25 white male slides, each preselected for high or low favorability. Since black slides were not judged as extreme as whites, the five most negative and five most positive black photographs were chosen and matched with slides of whites. Accordingly, the two most negative and the most positive white slides were not included in the experimental sequence because of their extreme ratings. The mean ratings for the low and high black and white groups were 4.15, 7.70, 4.22, and 7.56, respectively. Two t tests compared the mean black and white ratings for each favorability category; both t values were found to be nonsignificant (p > .05). Experimental design. The general experimental design was the same as Experiment I, except the sex of slide and sex of rater variables were excluded from consideration and the factor of initial affective favorability added. Also, instead of a completely randomized preand posttest slide sequence, slides were randomly presented with the restriction that every four trials were balanced for the variables of race and initial favorability. Procedure. There were three somewhat minor differences between the procedures used in Experiments I and II. First, a 4 sec intertrial interval was used for subjects to make their pre- and posttest ratings. Second, eight groups, averaging six subjects were alternately assigned to the experimental (exposure) and control (nonexposure) conditions. Finally no "demand characteristics" questions were used at the end of the experiment.
RESULTS T h e five ratings for e a c h race b y f a v o r a b i l i t y c a t e g o r y were t o t a l e d for each s u b j e c t in c a l c u l a t i n g the d e p e n d e n t m e a s u r e . A s in E x p e r i m e n t I, two r e p e a t e d m e a s u r e s a n a l y s e s o f v a r i a n c e were c o m p u t e d to e v a l u a t e s e p a r a t e l y differences in p r e t e s t ratings a n d a n y c h a n g e s p r o d u c e d b y mere exposure. The former analysis consisted of a 2 ( t r e a t m e n t ) × 2 (race) x 2 (initial f a v o r a b i l i t y ) a n a l y s i s of v a r i a n c e of the p r e t e s t measure, while the latter c o n s t i t u t e d a 2 ( t r e a t m e n t ) x 2 (tests) × 2 (race) x 2 (initial f a v o r a b i l i t y ) a n a l y s i s o n both the pre- a n d p o s t t e s t data.
Pretest Analysis Initialfavorability. T h e p r e t e s t a n a l y s i s r e v e a l e d a significant m a i n effect for the f a v o r a b i l i t y c a t e g o r y (p < .001). H e n c e , the effect represents a cross v a l i d a t i o n of the f a v o r a b i l i t y categories with a different s a m p l e o f s u b j e c t s t h a n u s e d in the p r e e x p e r i m e n t a l p r o c e d u r e . Treatment × race × initial favorability. T h i s triple o r d e r i n t e r a c t i o n y i e l d e d a significant effect ( F ( l , 4 8 ) = 6.39, p < .025). I n s p e c t i o n o f the cell m e a n s r e v e a l e d that the low f a v o r a b i l i t y white slides w e r e rated l o w e r t h a n the low f a v o r a b i l i t y b l a c k slides for the e x p e r i m e n t a l group. C o n v e r s e l y , for the c o n t r o l g r o u p , the low f a v o r a b i l i t y b l a c k slides were
21
INTERPERSONAL FAVORABILITY A.LOW FAVORABILITY 50 29 28 27 26
o---OEXPERIMENTAL GROUP I - - - . I C O N T R O L GROUP
24 ~ 25
B . H ~ H FAVORABILtTY 45 42 41 40 39
/
e
38 37 36' 35
23 22 21 20
34 33' i PRE
l POST
<
t PRE
I POST
TEST
FIG. 2. M e a n favorability rating as a function of e x p o s u r e and initial affective value across tests (Experiment Il).
rated lower than the white slides. However, since each small group was alternately assigned to each treatment group, this triple-order interaction probably represents an alpha error. Exposure Analysis T r e a t m e n t x tests. As in Experiment I, it is evident that the experimental group, which received the exposure condition, exhibited a larger pre- to posttest increase in affective ratings than did the control group (F(1,48) = 42.64, p < .001). A simple main effects analysis revealed that the judged favorability increased from pre- to posttest for the experimental group (F(1,24)= 25.72, p < .001), while no significant change occurred for the control group. T r e a t m e n t x initial favorability x tests. Convergence across tests did not take place for the high- and low-favorability categories. Figure 2 presents graphically the nonsignificant interaction (F(1,48) = 3.13, p > .10). As graph A of Fig. 2 indicates, an increase in favorability as a function of exposure was found for the slides initially rated as low in favorability. However, as graph B illustrates, exposure also produced an increase in affective rating for the high favorability slides, a result contrary to the convergence hypothesis. No other interaction effect relating to the exposure treatment was found to be significant.
DISCUSSION Experiment I
The significant overall T r e a t m e n t x Test interaction and subsequent simple main effects analyses indicated that exposure served to enhance
22
HAMM, BAUM A N D NIKELS
interpersonal favorability for experimental subjects, while no significant change in favorability occurred for the control (unexposed) subjects. Such results replicate Zajonc's (1968) "mere exposure effect" using photographs of human faces, as well as other laboratory studies dealing with exposure (Harrison, 1969; Johnson, Thomson, and Fincke, 1960; Perlman and Oskamp, 1971), and provides one of the few demonstrations of the effect with a between group design. Little can be said about the substantial, but nevertheless nonsignificant, decrease in the control group's favorability ratings from the pre- to posttest since no similar change occurred for the control group in Experiment II. Also, the significant interactions involving the treatment variable for the pretest results in both experiments are difficult to explain. They can only represent either two type I errors, or the presence of some unknown sampling bias. In addition to replicating the "mere exposure effect," analysis of the pretest favorability scores revealed the presence of several interesting interactions regarding the importance of sex and race in the impression formation process. However, little can be learned about real-life racism since no comparable sample of black subjects was included in the experiment and subjects evaluated pictures of individuals rather than the individuals themselves. Despite these limitations, future research should be done to assess the generalizability of the present laboratory findings. Experiment I I
As in Experiment I, the significant Treatments x Tests interaction replicated and extended the "mere exposure effect" across the variables of race and initial level of favorability. Hence, exposure to an integrated slide sequence was a sufficient condition for the enhancement of interpersonal attraction. Unlike Experiment I, only a slight decrease was observed across tests for the control group. From Rosenblood and Ostrom's (1971 ) study, it was expected that the ratings for the favorability categories would converge across tests. Such a prediction is consistent with an adaptation level theory of mere exposure. However, the results of the present experiment appear inconsistent with both the adaptation and association (classical conditioning) views of mere exposure. Regarding the latter, the negative affect associated with slides of low favorability would be expected to produce a decrease in liking as a function of exposure. Obviously, the opposite was found. The general response competition view represents the only theoretical orientation consistent with the present experimental results. Empirically speaking, the results of the present study may not be inconsistent with the earlier Rosenblood and Ostrom (1971) investigation. Inspection of their data reveals that a slight increase in favorability took
INTERPERSONAL FAVORABILITY
23
place for art pieces judged highly attractive. It was only after 20 exposures that a significant convergence in ratings occurred. Another important difference between the studies concerns the relative distinctiveness of categories. On a 7-point scale, they reported mean ratings of 2.55 for low favorability objects and 5.13 for high favorability objects. These means indicated that they used favorability categories which were more extreme than in the present study. Finally, human faces are certainly different from abstract art, and it is quite possible that exposure may produce a different effect for each type of stimulus. Indeed, like the present investigation, a recent study reported by Saegert, Swap, and Zajonc (1973) found that interpersonal attraction increased as a positive function of number of encounters, regardless of the situational context. Finally, the fact that Burgess and Sales (1971), Perlman and Oskamp (1971) and the present study varied the inherent attractiveness of the object may account for the difference in results. R a c e and M e r e Exposure
Perhaps the most important result of Experiments I and 1I was the absence of significant Treatment x Tests x R a c e interactions. Regardless of race of slide, therefore, exposure served to enhance the interpersonal attractiveness of both black and white individuals. The context of the social interaction may reveal racial differences, as recently reported by Perlman and Oskamp (1971). They presented black and white individuals in positive, neutral, and negative behavioral settings to their subjects. They found that positive behavior contexts enhanced attitudes while negative contexts decreased attitudes. However, black photographs displayed a smaller effect of positive exposure and a larger effect of negative exposure than white individuals. Generalizing the results of the present study to real-life interaction or integration must be made with extreme caution (see (Amir, 1969)). However, despite the potential importance of social context, the present study might suggest that nominal exposure to blacks might be sufficient condition for attitudinal enhancement on the part of white Americans. Future research should seek to evaluate the generalizability of the present laboratory results to real-life integrated situations.
REFERENCES AMIR, Y. Contact hypothesis in ethnic relations. Psycholoq, ical Bulletin, 1969, 71, 319-342. BRICKMAN, P., & REDFIELD, J. Drive and predisposition as factors in the attitudinal effects of mere exposure. Paper presented at the meeting of American Psychological Association, Miami Beach, September 1970. BURGESS, T. D. G., II, & SALES, S. M. Attitudinal effects of mere exposure: A re-evaluation. Journal of Experimental Social Psychology, 1971, 7, 461-472.
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HARRISON, A. A. Exposure, favorability, and item endorsement. Psychological Reports, 1968, 23, 1070. (a) HARRISON, A. A. Response competition, frequency, exploratory behavior, and liking. Journal of Personality and Social Psychology, 1968, 9, 363-368, (b) HARRISON, A. A. Exposure and popularity. Journal of Personality, 1969, 37, 359-377. HARRISON, A. A., & ZAJONC, R. B. The effects of frequency and duration of exposure on response competition and affective ratings. Journal of Psychology, 1970, 75, 163-169. JOHNSON, R. C., THOMSON, C. W., & FINCKE, G. Word values, word frequency, and visual duration thresholds. Psychological Review, 1960, 67, 332-342. JUNG, J., & BAILEY, J. Contemporary Psychology Experiments: Adaptations for the Laboratory. New York: Wiley, 1966. ORNE, M. T. On the social psychology of the psychological experiment: With particular reference to demand characteristics and their implications. American Psychologist, 1962, 12, 776-783. PERLMAN, D., & OSKAMP, S. The effects of picture content and exposure frequency on evaluations of Negroes and whites. Journal of Experimental Social Psychology, 1971, 7, 503-514. ROSENBLOOD, L., & OSTROM, T. M. Is "mere exposure" merely adaptation? Paper presented at the Midwestern Psychological Association, Detroit, May 1971. ROSNOW, R. L., & SULS, J. M. Reactive effects of pretesting in attitude research. Journal of Personality and Social Psychology, 1970, 15, 338-343. SAEGERT, S., SWAP, W., & ZAJONC, R. B. Exposure, context, and interpersonal attraction. Journal of Persona6ty and Social Psychology, 1973, 25, 234-242. STRASSBURGER,F., & WERTHEIMER, M. The discrepancy hypothesis of affect and association value of nonsense syllables. Psychological Reports, 1959, 5, 528. ZAJONC, R. B. Attitudinal effects of mere exposure. Journal of Personality and Social Psychology, 1968, 9 (2, part 2), 1-27. ZAJONC, R. B. & RAJECKI, D. W. Exposure and affect: A field experiment. Psychonomic Science, 1969, 17, 216-217. ZA~ONC, R. B., SHAVER, P., TRAVIS, C., & VAN KREVELD, D. Exposure, satiation, and discrimination. Journal of Personality and Social Psychology, 1972, 21, 270-280.