- Email: [email protected]
Permissive introduction and anchoring in altering perceptual-judgmental processes and the impact of a persuasive communication
JOURNAL
OF
EXPERIMENTAL
Permissive
SOCIAL
PSYCHOLOGY
Introduction
and
5, 417428
Anchoring
Perceptual-Judgmental Processes Impact of a Persuasive Communication RONALD
C. DILLEHAY University
( 1969)
in Altering and
the
AND PHILIP K. BERGER of Kentucky
Previous research on the influence of external anchors on judgment of a persuasive communication has produced conflicting results. Permissive introduction to a communication is investigated in this study for its importance in judgmental responses and subsequent opinion effects, and is used to account for the previous inconsistent results concerning anchoring. Following anchoring or permissive introduction or both, subjects judged the position advocated in a communication dealing with treatment of juvenile delinquents and registered their own opinions on the issue. The data support the hypothesis that permissive introduction alters judgment of the communicator’s position, whereas anchors alone do not produce a significant difference. Opinion effects are consistent with the judgmental results and indicate that the more extreme the perceived stand advocated in the communication, the greater the opinion change. The effects of a permissive introduction are discussed in terms of alternative hypotheses of an atmosphere effect or salience for alternative attitudinal stands.
Reaction to a persuasive communication can be conceptualized as a two-stage process, the first stage entailing a perceptual-judgmental activity of locating the communication along a continuum of favorability toward the topic of the communication and the second stage involving the incorporation or rejection of the message content. Both features of reaction to persuasion have been included in the formulations by Hovland, Harvey, and Sherif ( 1957; see also Sherif and Hovland, 1961). An important consideration in both aspects of this two-part process is the discrepancy between the attitudinal position of the message recipient and the stand advocated in the communication. Regarding the perceptual-judgmental activity, any factor that systematically influences the characteristics of the subjective scales of judgment utilized by listeners should produce systematic effects upon judgment. The use of anchors in research with psychophysical continua has 417
418
DILLEHAY
AND
BERGEfl
produced such systematic effects, described as contrast and assimilation (e.g., Rogers, 1941; Sherif, Taub, and Hovland, 1958). Contrast, a shift in judgment away from an anchor, has been shown to increase as the anchors are made more and more remote on the stimulus scale from the stimuli being judged. One interpretation of this phenomenon has been that the scale of judgment is extended to the anchors, sliding past the stimuli and causing them to be placed in categories more distant from the end of the scale that contains the anchor. An alternative statement of this effect is that the scale does not change, but that the categories are redefined due to the introduction of the anchor on the scale so that the stimuli being judged are displaced down the scale. Several studies report the use of external anchors with social phenomena. Weiss (1958), employing a scale of punitiveness toward juvenile delinquents, used statements of extreme opinions on the treatment of juvenile delinquents as anchors, with one extreme opinion for each end of the scale. He obtained less extreme judgments of a moderately punitive communicator when the anchors were present than when the communicator was judged without the anchors. That is, the results appear to indicate judgmental contrast with the anchors. Weiss introduced the anchors to his subjects by statements “to the effect that some people hold to the opinion extremes of complete leniency or excessive punitiveness (p. 380). However, Choo (1964) was unable to toward delinquents” replicate Weiss’s findings. In another experiment dealing with external anchoring and a persuasive communication, Dillehay (1965) failed to obtain a contrast effect. His procedure, different from that used by Weiss and more clearly analogous to the psychophysical paradigm, was to provide three extreme statements on only one end of the scale or the other. The statements were introduced as examples of what some people had said about the issue. While the failure of anchoring effects under these circumstances could have been due to a number of factors, it prompted close re-examination of anchoring in both studies. This re-examination suggested the influence of a factor here termed permissive introduction to a persuasive communication which should influence the subjective scale of judgment in a manner comparable to the theoretical effects of anchoring. Permissive introduction, thus, is another theoretically appropriate method to achieve systematic alterations in subjective judgments of the position advocated in a persuasive communication. In perhaps the most general case, a permissive introduction might consist of statements that suggest a wide range of existing opinion on the issue. In fact, Weiss used just such an introduction, disregarding any effect it might have. In his study, permissive introduction was inadvertent and completely confounded with the anchoring treatment in such a way as to combine the
PERMISSIVE
INTHODUCTION
TO
A
COMMUNICATION
419
effects of the two factors. It is, therefore, possible that the effects he attributed to anchoring were, in fact, due to the effects of a permissive introduction. The theoretical basis for expecting systematic alterations of the scale of judgment following permissive introduction is twofold. First, such remarks might serve to remind subjects of specific extreme points of view, producing the effect of broadly based, internally supplied anchors (cf. Dillehay, 1965). A well-anchored scale, particularly at the extremes, should yield apparent contrast effects with the end points of the scale, showing judgment of a communicator’s position as less extreme than when judgment occurs without the permissive introduction. This effect might be regarded as increased salience of varying opinions. Second, an alternative possibility is that permissive introduction might produce an atmosphere or mood of toIerance for views discrepant from the listener’s, serving to minimize distinctions among the various positions on the issue and to blur discrepancies between the recipient’s original position and the position advocated by the message. The outcome should then be perception of a discrepant communicator’s position as nearer to the listener’s attitudinal position. The resulting assimilation effect should hold especially in the case of considerable discrepancy between the listener’s point of view and that advocated by the communicator. In any case, either or both of these processes should result in less extreme judgments of a moderately extreme communicator when he is introduced by permissive remarks to an audience holding views less extreme than those in the message. The major hypothesis tested in this experiment with respect to judgment of a persuasive communication is that permissive introduction preceding a persuasive communication that takes a moderate but plainly fixed point of view makes the communication appear less extreme. A secondary hypothesis tested is that anchors in the form of positive and negative opinions that represent extreme positions on the scale of judgment make a communication appear less extreme than when that communication is judged in the absence of these anchors. These hypotheses are based on theoretical support rather than empirical support due to the alternative interpretations possible in Weiss’s study and the failure of an anchoring effect in the previous anchoring experiment by the first author and by Choo ( 1964). One interest in external anchoring, and presumably other procedures for altering perception of a persuasive communication, is that systematically altered judgment should act as a mediator for attitude change. That is, if communicators can be made to appear less extreme, their impact may be greater when one is dealing with controversial issues, and less when one is dealing with relativeIy factual, noninvolving matters.
420
DILLEHAY
AND
BERGEZI
This relationship between discrepancy between communicator and audience and impact has been discussed by Hovland and his co-workers (Hovland, 1959; Hovland et al., 1957; Sherif and Hovland, 1961), and explored in a number of systematic studies of the discrepancy variable (e.g., Hovland and Pritzker, 1957; Bochner and Insko, 1966). In the only study of successful manipulation of the communicator’s position, Weiss (1958) found the greater absolute change in opinion among those who judged the communicator to be more extreme. But when one is considering the role of discrepancy in conjunction with an alteration in perception of the communication due to some manipulation of the scale of judgment, one must take into account the possible direct influence upon opinions of the procedures that alter perception of the communication. In the study by Weiss ( 1958), for example, it is possible that the opinion changes were a result, not of an altered impact of the communication due to differential perception of the content, but of the anchors or statements comprising the permissive introduction operating directly upon opinion. This latter effect could be due theoretically to either an alteration in opinions due to the anchoring or introduction, or to a differential perception of the statements that made up the scale on which the subjects registered their opinions. In either event, the effect is directly upon opinions and does not require the intervening change in perception of a persuasive communication. This question is not merely a methodological one, but has theoretical substance as well. One such feature is whether opinion changes can be induced directly through altering the scale of judgment to which they are referred. This kind of change is one of redefining attitudinal positions on the scale through a change in that scale but not changing the content of opinion; whereas the more typical view of attitude change is one in which an alteration in content is manifested by a change of location on the scale. Anchoring and permissive introductions may have either of these effects. With regard to opinion change, this experiment examines the differential influence of a persuasive communication that is preceded by anchors, permissive introduction, or both. It further examines the direct impact of such manipulations upon opinions in the absence of an intervening communication. METHOD Subjects
Ninety-nine at Texas requirement.
male and 192 Christian University
female students in the introductory participated in this experiment
psychology as part of
course a course
PERMISSIVE
INT-RODUCXION
TO
A
COMMUNICATION
421
Design An after-only design was employed. Four groups read a communication from an anonymous source favoring more punitive action toward juvenile delinquency, and three control groups were not exposed to the communication. The communication groups were: ( 1) Communication plus permissive introduction plus anchors ( Comm f PI f A) : Subjects in this group (N = 41) were introduced to the communication as follows: “Because the topic of juvenile delinquency is controversial, different people hold extremely differing opinions about the treatment of juvenile delinquents. Some people express opinions of complete leniency in dealing with juvenile delinquents. For example: ‘Delinquents should only be treated with sympathetic understanding, guidance, and re-education; for the punishment of misguided youngsters is brutal and degrading.’ Other people, with directly opposite views, express opinions of extreme punishment. For example: ‘All delinquents should be given long-term prison sentences and very severe physical punishment.’ In fact, the treatment of juvenile delinquents is one of those issues on which all degrees of opinion exist.” The two examples of extreme opinions are the anchors while the remainder of the text constitutes the permissive introduction. The anchors are those reported by Weiss (1959). The permissive introduction and/or anchors were presented on a separate page preceding the communication, which was entitled “Dealing with Juvenile Delinquents.” By this procedure we hoped to clearly separate the introduction and anchoring treatments from the communication proper. (2) Communication plus permissive introduction (Comm $ PI): Subjects in this group (N = 42) were introduced to the communication with only the permissive introduction cited above, i.e., the examples (anchors) were omitted. (3) Communication plus anchors ( Comm f A) : Subjects in this group (N = 41) were introduced to the communication with the examples (anchors) from the introduction cited above without the permissive introduction material. (4) Communication only (Comm only) : Subjects in this group (N = 43) read the communication without a permissive introduction or anchors. All communication groups responded to a modification (for juvenile delinquents ) of the Wang-Thurstone scale on the treatment of criminals as they thought the communicator would respond. Subjects’ responses reflected whether the communicator would agree or disagree with each item on modified Form A. Following this rating, ::ubjects responded to a modification of Form B in terms of their own opinion. Three control groups received no communication and did not make judgments of the communicator’s position on juvenile delinquency: ( 1) Control No PI, No A. Members in this group (N = 42) just rated each statement on modified Form A along an 11-point scale in terms of its favorableness or unfavorableness to punishment of juvenile delinquents.’ Own opinion on treatment of delinquents was obtained from responses to modified Form B. ‘The purpose of having control subjects judge the Form A items was to provide them with experience over the same content as the communication groups, save fol the communication itself. The additional possibility that judgments of these items might prove useful in examining the operation of the permissive introduction and anchors was precluded by large variabilities in item judgments. Inspection of the patterns of judgment5 suggested that the large variabilities were due to the failure of slightly over half of the subjects to judge Form A according to the leniency and harshness of the items rather than agree or disagree with them. This was surprising
422
DILLEHAY
(2) Control rating the
+ items
PI. The
permissive
AND
BERGER
introduction
preceded
Form A of the modified (N = 41) expressed their own opinion on modified
on
(3) mod&xl
Control Form
Experimental
$ A. The two A. Own opinion
Pretest on the anonymous punitive given
Form B. embedded in the instructions on rating on modified Form B (N = 41).
anchors were was obtained
“criminal”
communication
indicated
that it was moderateIy
treatment of juvenile delinquents. to the communication was 10.2.
The Wang-Thurstone word
instructions
scale. Subject.;
Matetials
able toward average rating the
subjects’
Wang-Thurstone
from
with
scale on treatment
On
of criminals
a 19point
was modified
favor-
scale,
the
by replacing
“delinquent.”
Procedure Data were collected in group sessions, with the number per session ranging from 20 to 50. Booklets to each session.
containing Subjects
each were
of the seven treatments were randomly ordered told that they were participating in a study
of
prior the
judgment of other people’s opinions, and that the topic being considered was juvenile deknquency. It was pointed out that their responses were anonymous. The Wang-Thurstone scales were scored value of one and antipunitive responses a scored under this procedure and were deleted of the communicator’s position on punitiveness
and own opinion on punitiveness
by
assigning
propunitive
value of zero. Neutral from the is based
responses
a
items cannot be
following analyses. Judgment upon 18 items from Form A,
is based upon 17 Form B items. RESULTS
Judgment
of Communicator’s
Position
A preliminary 2 X 2 X 2 (permissive introduction X anchor X factorial analysis of variance for unequal N (unweighted means) computed to determine whether sex difference interacted with the ments. None of the relevant interactions were signifkant nor was
sex) was treatthere
a main effect due to sex. Data for males and females were then combined, and a 2 x 2 factorial analysis of variance for unequal N was performed (Table 1). Results of this analysis indicated that the main effect due to permissive introduction was significant (F = 3.92, 1 and 163 df, p < .OS), but that the anchoring manipulation was not. Individual comparisons between means (Table 2) were made using the t statistic suggested by Winer (1962, p. 244) for use with unequal KS. The Comm + PI + A group, which is analogous to Weiss’s (1958) original End Standards condition, attributed less punitiveness to the communicator than did the Comm Only group (t = 2.12, 163 df, p < .025).* to us since the judgment successfully used in prior ’ One-tailed test.
instructions to subjects studies by the first author
had been pretested elsewhere and with different college populations.
PERMWVE
I~ODU&ION
TO
TABLE ANALYSIS
OF VARIANCE
OF JUDGMENT
423
A COMMUNICA-~ION
1 OF COMMUNICATOR’S
Source
df
Anchors vs. no anchors (A) Permissive introduction vs. no permissive introduction AXB Within-cell error
MS
1
(B)
POSITION
1 1
163
13.76 51.30 .83 13.10
F
3.92*
* p < .05. TABLE MEAN
JUDGMENTS
Anchors No anchors
2
OF COMMUNICATOR’S
POSITION
Permissive introduction
No permissive introduction
11.44 11.86
12.39 13.12
The Comm Only group is analogous to Weiss’s No Standards condition. The Comm + PI group also judged that the communicator advocated a less punitive position than did the Comm Only group (t = 1.60, 163 rlf, p < .10).2 There was no difference in judgment of the communicator’s position between the Comm + A and the Comm Only groups. In an attempt to determine whether the manipulations affected the punitive items, the lenient items, or both, the beliefs attributed to the communicator in each of the communication groups were examined. These analyses showed that in the PI + A group there was a greater tendency to attribute lenient beliefs to the communicator and a lesser inclination to attribute punitive beliefs to him relative to the Comm Only group. That is, the locus of the effect for the PI + A group is in both the lenient items and the punitive items of the scale used to measure the perceived stand of the communicator. This analysis was done by using the sign test to compare the differences between proportions of agreement for the communicator in the two groups on lenient and punitive items on the Wang-Thurstone Form A scale. Considering the Comm Only vs. Comm + PI + A comparison, the number of punitive items on which a greater proportion of subjects in the Comm Only group agreed was significant ( p = .039) ; the number of lenient items with a higher proportion of Comm Only subjects disagreeing was significant ( p = .07). Combined the difference was highly sign&cant (p = .002). Comparable comparisons for the Comm Only and the Comm + PI groups showed the
424
DILLEHAY
effect on ence for None of proached
AND
BERGER
the punitive items to be significant ( p = .039), with no differthe lenient items ( p = .50) and items combined (p = .14). the comparisions involving Comm Only and Comm + A apsignificance.
Own Opinion The first of variance cant (F = groups (F
analysis of subject’s own opinion was a 2 x 7 factorial analysis for unequal N (Table 3). Main effects due to sex are signifi8.56, 1 and 277 df, p < .Ol) as are main effects for treatment = 3.25,6 and 277 df, p < .Ol). TABLE ANALYSIS
OF VARIANCE
Source
sex(A) Treatment groups (B) AXB Within-cell *p
error
~h'ISIOX
df
MS
F
1 6 6 277
36.07 24.31 2.71 6.55
8..56* 3.2.5*
< .Ol. TABLE MEAN
Males Females
3 OF OWS
OWN
OPINIOS
4
FOP, COMMUNICATION
Comm only
Comm +A
Comm + PI
8.50 6.79
7.40 6.27
7.08 6.13
AXD
CONTROL
GROTPS
Comm
Control
Control
Control, no PI,
+PI+A
+PI
+A
no A
.5.76 5.71
6.38 4.96
5.83 5.17
6.56 5.88
Individual comparisons between means were tested using the NewmanKeuls technique with the level of significance established at p < .05. The comparisons reported here are for marginal means, i.e., for treatment main effects rather than for simple main effects on males and females separately. The Comm Only group was significantly more punitive than the other communication groups and the controls. The Comm + A group held a significantly more punitive opinion than did the three controls. The Comm + PI group was also significantly more punitive than the three controls. No other means were significantly different from one another. A second analysis of own opinion was performed on scores from the four communication groups. A preliminary 2 X 2 X 2 factorial analysis of variance for unequal N established that none of the interactions asso-
PERMISSIVE
INTFiODUCI-ION
TO
425
A COMMUNICATION
ciated with sex approached significance. The sex main effect was significant. Table 5 shows the 2 x 2 factorial analysis of variance for unequal N computed on the combined male and female data. The permissive introduction main effect was significant at the .lO level (F = 3.56, 1 and 163 df). Ana~~srs
OF VARIANCE OF OWN
TABLE 5 OPINION FOR COMMUNICATION GROUPS
Source
Anchors vs. no anchors (A) Permissive introduction vs. no permissive introduction AXB Within-cell error *p
(B)
c1.f
MS
F
1 1 1 163
11.68 27.11 .83 7.62
1.53 3.56*
< .lO.
Individual comparisons between means (Table 6) were made using the t statistic suggested by Winer (1962, p. 244), The Comm + PI + A group, analogous to Weiss’s Ends Standards condition, expressed less punitiveness than did the Comm Only group, analogous to Weiss’s No Standards condition (t = 2.21, 163 df, p < .025).2 The Comm + PI group was also slightly less punitive in its opinion than the Comm Only group (t = 1.59, 163 df, p < .10).2 There were no differences in own opinion between the Comm + A and Comm Only groups ( t < 1). MEAN Owr
TABLE 6 OPINION FOR COMMUNICATION GROUPS Permissive introduction
Anchors No anchors
6.02 6.40
No permissive introduction 6.68 7.35
DISCUSSION
The results offer clear support for the hypothesis that a permissive introduction alters judgment of a persuasive communication that argues for a moderately extreme stand on a social issue. Anchoring, on the other hand, was found to be ineffective in bringing about a significant judgmental effect. With regard to consequences for opinions, the otherwise effective communication was rendered ineffective by the combination of variables of permissive introduction and anchors. Although the communication with either permissive introduction or anchors produced significant opinion change, this change was reliably less than the amount
426
DILLEHAY
AND
BERGER
produced by the communication alone. There was no suppon ror the notion that a permissive introduction or a set of anchors alone is sufficient to yield directly a change in opinion without the accompaniment of a communication. Permksive Zntroduction
as Context for a Persuasive Communication
One hypothesis that may account for the effects of a permissive introduction upon judgment of a persuasive communication can be referred to as a mood or atmosphere effect; a second possible interpretation concerns the salience of the variety of possible positions on the subjective scale of judgment. In either case the consequences should bc to reduce the perceived extremity of the stand advocated in the communication. The data presented here are not consistent with the idea that a permissive introduction to the issue in the absence of a persuasive communication has a direct impact upon opinions; or, if it does, the effects in this experiment are offset by changes in complementary directions by different subjects. If the permissive introductions operated directly upon opinions in a way consistent with either of the hypotheses just described, subjects in this study receiving the permissive introduction and no communication would have become less lenient in their advocated treatment of juvenile delinquents (from their somewhat lenient positions suggested by the control group’s position) because of either less discrimination along the scale of judgment or because of a more highly differentiated judgmental scale. Concerning the impact of the communication upon opinions about the treatment of juvenile delinquency, there was a marginally significant reduced impact due to permissive introduction alone with the communication, and a more significant outcome when anchors were utilized with the permissive introduction. These results fit the pattern of judgmental differences with the overall outcome that the less extreme the communicator was judged to be, the less change in opinion he brought about. These findings agree with that portion of the literature (e.g., Hovland and Pritzker, 1957; Weiss, 1958) that indicates greater change with greater discrepancies between the communicator’s position and the attitudinal positions of the communication recipients, and disagree with those findings that smaller discrepancies are more likely to produce change than larger ones (e.g., Hovland et al., 1957; Sherif and Hovland, 1961). A persistent problem with the reconciliation of these seemingly contradictory results is the distinction between emotionally involving and non-involving issues, which is suggested as the basis on which one can predict the amount of change likely to occur. For the present experiment the question would seem to be, is the treatment of juvenile delinquents it
PERMISSIVE
INTRODUCTION
TO
A
COMMUNICATION
421’
sufficiently involving issue for the subjects? The issue is probably less involving than prohibition or politics, which were studied by Hovland and his associates (see Hovland, 1959). An additional problem, of course, is the matter of the absolute discrepancies between the subjects’ positions and the perceived stand taken in the communications that are included in the study. Some difference is obviously required before change could be expected even with the most involving issue, and an extremely great discrepancy for even a non-involving issue may lead to rejection of the communication and to no effects upon opinions, or even changes opposite to the stand advocated by the communicator. The Use of External
Anchors with Persuasive Communications
With the clarification provided by the present study, we may conclude on present evidence that deliberately supplied external anchors in the fern? of examples of opinions that people hold on the topic of the communication are not effective in altering perception of the stand advocated in the commmlication. Previous negative evidence (Choo, 1964; Dillehay, 1965) and the explication and reinterpretation of Weiss’s ( 1958) findings as a consequence of the operation of a permissive introduction provide the basis for such a conclusion. It should be noted, however, that these studies have utilized opinion statements for anchors that contain a tone of reason in contrast to emotion. It is possible that emotional, inflammatory anchors might produce the predicted contrast effects. Other kinds of anchors in the communication situation, such as the invested position of the communicator as determined by previous knowledge (Dillehay and Lerner, 1968) or the attitudinal position of a significant person other than the communicator in the situation might be effective. While anchors alone did not yield effects, anchors in the form of opinion statements at the extreme positions on the scale did augment the effects of a permissive introduction, It seems plausible that the anchors supplement recall of opinion statements when the audience is induced to do so by a permissive introduction. An assumption concerning the utilization of this hypothesis to account for the differences between the impact of anchors and that of a permissive introduction is that the permissive introduction is more effective in evoking alternative positions on the judgmental scale than are anchors. The data from the present study present no support for the possibility that the use of external anchors in the form of examples of opinion extremes directly alter expressed opinions in the absence of an intervening communication. The findings of this experiment have interesting theoretical and prac-
428
DILLEHAY
AND
BERGER
tical consequences. The influence of a permissive introduction significantly modified the perceived position of the communicator and eliminated his impact upon the opinions of the audience. These consequences were even more pronounced when anchors were included with the permissive introduction. A curious paradox is contained in this kind of introduction. Using a permissive introduction one appears to be tolerant and fair, recognizing a variety of opinions on the issue at the same time he is neutralizing the impact of the communication to follow. REFERENCES BOCHNER, S., AND INSKO, C. A. Communicator discrepancy, source credibility, aud opinion change. Journal of Personality and Social Psychology, 1966, 41, 614-621. CHOO, TONG-HE. Communicator credibility and communication discrepancy as determinants of opinion change. Journal of Social Psychology, 1964, 64, 65-76. DLLLEHAY, R. C. Judgmental processes in response to a persuasive communication. Journal of Personality and Social Psychology, 1965, 1, 631-641. D~LEHAY, R. C., AND LERNER, M. J. Judgment of a persuasive communication as a function of recipient attitude, speaker, and message, Paper presented at the meeting of the Southwestern Psychological Association, New Orleans, April, 1968. HOVLAND, C. I. Reconciling conflicting results derived from experimental and survey studies of attitude change. American Psychologist, 1959, 14, 8-17. HOVLAND, C. I., HARVEY, 0. J., AND SHERIF, M. Assimilation and contrast eflects in reactions to communication and attitude change. Journal of Abnormal and Social Psychology,
1957, 55, 244-252.
C. I., AND PF~ITZKER, H. A. Extent of opinion change as a function of amount of change advocated. Journal of Abnormal and Social Psychology, 1957, 54,257-261. ROGERS, S. The anchoring of absolute judgments. Archives of Psychology, 1941, 37, No. 261. SHERIF, M., AND HOVLAND, C. I. Social judgment. New Haven: Yale University Press, 1961. SHERIF, M., TAUB, D., AND HOVLAND, C. I. Assimilation and contrast effects of anchor stimuli and judgments. Journal of Experimental Psychology, 1958, 55, 150-155. WEISS, W. The relationships between judgments of a communicator’s position and extent of opinion change. journal of Abnormal and Social Psychology, 1958, 56, 380-384. WEISS, W. The effects on opinions of a change in scale judgments. Journal of Abnormal and Social PsychoZogy, 1959, 58, 329-334. WINER, B. J. Statistical principles in experimental design. New York: McGraw-Hi]!. 1962.
HOVLAND,
(Received July 5, 1968)
OF
EXPERIMENTAL
Permissive
SOCIAL
PSYCHOLOGY
Introduction
and
5, 417428
Anchoring
Perceptual-Judgmental Processes Impact of a Persuasive Communication RONALD
C. DILLEHAY University
( 1969)
in Altering and
the
AND PHILIP K. BERGER of Kentucky
Previous research on the influence of external anchors on judgment of a persuasive communication has produced conflicting results. Permissive introduction to a communication is investigated in this study for its importance in judgmental responses and subsequent opinion effects, and is used to account for the previous inconsistent results concerning anchoring. Following anchoring or permissive introduction or both, subjects judged the position advocated in a communication dealing with treatment of juvenile delinquents and registered their own opinions on the issue. The data support the hypothesis that permissive introduction alters judgment of the communicator’s position, whereas anchors alone do not produce a significant difference. Opinion effects are consistent with the judgmental results and indicate that the more extreme the perceived stand advocated in the communication, the greater the opinion change. The effects of a permissive introduction are discussed in terms of alternative hypotheses of an atmosphere effect or salience for alternative attitudinal stands.
Reaction to a persuasive communication can be conceptualized as a two-stage process, the first stage entailing a perceptual-judgmental activity of locating the communication along a continuum of favorability toward the topic of the communication and the second stage involving the incorporation or rejection of the message content. Both features of reaction to persuasion have been included in the formulations by Hovland, Harvey, and Sherif ( 1957; see also Sherif and Hovland, 1961). An important consideration in both aspects of this two-part process is the discrepancy between the attitudinal position of the message recipient and the stand advocated in the communication. Regarding the perceptual-judgmental activity, any factor that systematically influences the characteristics of the subjective scales of judgment utilized by listeners should produce systematic effects upon judgment. The use of anchors in research with psychophysical continua has 417
418
DILLEHAY
AND
BERGEfl
produced such systematic effects, described as contrast and assimilation (e.g., Rogers, 1941; Sherif, Taub, and Hovland, 1958). Contrast, a shift in judgment away from an anchor, has been shown to increase as the anchors are made more and more remote on the stimulus scale from the stimuli being judged. One interpretation of this phenomenon has been that the scale of judgment is extended to the anchors, sliding past the stimuli and causing them to be placed in categories more distant from the end of the scale that contains the anchor. An alternative statement of this effect is that the scale does not change, but that the categories are redefined due to the introduction of the anchor on the scale so that the stimuli being judged are displaced down the scale. Several studies report the use of external anchors with social phenomena. Weiss (1958), employing a scale of punitiveness toward juvenile delinquents, used statements of extreme opinions on the treatment of juvenile delinquents as anchors, with one extreme opinion for each end of the scale. He obtained less extreme judgments of a moderately punitive communicator when the anchors were present than when the communicator was judged without the anchors. That is, the results appear to indicate judgmental contrast with the anchors. Weiss introduced the anchors to his subjects by statements “to the effect that some people hold to the opinion extremes of complete leniency or excessive punitiveness (p. 380). However, Choo (1964) was unable to toward delinquents” replicate Weiss’s findings. In another experiment dealing with external anchoring and a persuasive communication, Dillehay (1965) failed to obtain a contrast effect. His procedure, different from that used by Weiss and more clearly analogous to the psychophysical paradigm, was to provide three extreme statements on only one end of the scale or the other. The statements were introduced as examples of what some people had said about the issue. While the failure of anchoring effects under these circumstances could have been due to a number of factors, it prompted close re-examination of anchoring in both studies. This re-examination suggested the influence of a factor here termed permissive introduction to a persuasive communication which should influence the subjective scale of judgment in a manner comparable to the theoretical effects of anchoring. Permissive introduction, thus, is another theoretically appropriate method to achieve systematic alterations in subjective judgments of the position advocated in a persuasive communication. In perhaps the most general case, a permissive introduction might consist of statements that suggest a wide range of existing opinion on the issue. In fact, Weiss used just such an introduction, disregarding any effect it might have. In his study, permissive introduction was inadvertent and completely confounded with the anchoring treatment in such a way as to combine the
PERMISSIVE
INTHODUCTION
TO
A
COMMUNICATION
419
effects of the two factors. It is, therefore, possible that the effects he attributed to anchoring were, in fact, due to the effects of a permissive introduction. The theoretical basis for expecting systematic alterations of the scale of judgment following permissive introduction is twofold. First, such remarks might serve to remind subjects of specific extreme points of view, producing the effect of broadly based, internally supplied anchors (cf. Dillehay, 1965). A well-anchored scale, particularly at the extremes, should yield apparent contrast effects with the end points of the scale, showing judgment of a communicator’s position as less extreme than when judgment occurs without the permissive introduction. This effect might be regarded as increased salience of varying opinions. Second, an alternative possibility is that permissive introduction might produce an atmosphere or mood of toIerance for views discrepant from the listener’s, serving to minimize distinctions among the various positions on the issue and to blur discrepancies between the recipient’s original position and the position advocated by the message. The outcome should then be perception of a discrepant communicator’s position as nearer to the listener’s attitudinal position. The resulting assimilation effect should hold especially in the case of considerable discrepancy between the listener’s point of view and that advocated by the communicator. In any case, either or both of these processes should result in less extreme judgments of a moderately extreme communicator when he is introduced by permissive remarks to an audience holding views less extreme than those in the message. The major hypothesis tested in this experiment with respect to judgment of a persuasive communication is that permissive introduction preceding a persuasive communication that takes a moderate but plainly fixed point of view makes the communication appear less extreme. A secondary hypothesis tested is that anchors in the form of positive and negative opinions that represent extreme positions on the scale of judgment make a communication appear less extreme than when that communication is judged in the absence of these anchors. These hypotheses are based on theoretical support rather than empirical support due to the alternative interpretations possible in Weiss’s study and the failure of an anchoring effect in the previous anchoring experiment by the first author and by Choo ( 1964). One interest in external anchoring, and presumably other procedures for altering perception of a persuasive communication, is that systematically altered judgment should act as a mediator for attitude change. That is, if communicators can be made to appear less extreme, their impact may be greater when one is dealing with controversial issues, and less when one is dealing with relativeIy factual, noninvolving matters.
420
DILLEHAY
AND
BERGEZI
This relationship between discrepancy between communicator and audience and impact has been discussed by Hovland and his co-workers (Hovland, 1959; Hovland et al., 1957; Sherif and Hovland, 1961), and explored in a number of systematic studies of the discrepancy variable (e.g., Hovland and Pritzker, 1957; Bochner and Insko, 1966). In the only study of successful manipulation of the communicator’s position, Weiss (1958) found the greater absolute change in opinion among those who judged the communicator to be more extreme. But when one is considering the role of discrepancy in conjunction with an alteration in perception of the communication due to some manipulation of the scale of judgment, one must take into account the possible direct influence upon opinions of the procedures that alter perception of the communication. In the study by Weiss ( 1958), for example, it is possible that the opinion changes were a result, not of an altered impact of the communication due to differential perception of the content, but of the anchors or statements comprising the permissive introduction operating directly upon opinion. This latter effect could be due theoretically to either an alteration in opinions due to the anchoring or introduction, or to a differential perception of the statements that made up the scale on which the subjects registered their opinions. In either event, the effect is directly upon opinions and does not require the intervening change in perception of a persuasive communication. This question is not merely a methodological one, but has theoretical substance as well. One such feature is whether opinion changes can be induced directly through altering the scale of judgment to which they are referred. This kind of change is one of redefining attitudinal positions on the scale through a change in that scale but not changing the content of opinion; whereas the more typical view of attitude change is one in which an alteration in content is manifested by a change of location on the scale. Anchoring and permissive introductions may have either of these effects. With regard to opinion change, this experiment examines the differential influence of a persuasive communication that is preceded by anchors, permissive introduction, or both. It further examines the direct impact of such manipulations upon opinions in the absence of an intervening communication. METHOD Subjects
Ninety-nine at Texas requirement.
male and 192 Christian University
female students in the introductory participated in this experiment
psychology as part of
course a course
PERMISSIVE
INT-RODUCXION
TO
A
COMMUNICATION
421
Design An after-only design was employed. Four groups read a communication from an anonymous source favoring more punitive action toward juvenile delinquency, and three control groups were not exposed to the communication. The communication groups were: ( 1) Communication plus permissive introduction plus anchors ( Comm f PI f A) : Subjects in this group (N = 41) were introduced to the communication as follows: “Because the topic of juvenile delinquency is controversial, different people hold extremely differing opinions about the treatment of juvenile delinquents. Some people express opinions of complete leniency in dealing with juvenile delinquents. For example: ‘Delinquents should only be treated with sympathetic understanding, guidance, and re-education; for the punishment of misguided youngsters is brutal and degrading.’ Other people, with directly opposite views, express opinions of extreme punishment. For example: ‘All delinquents should be given long-term prison sentences and very severe physical punishment.’ In fact, the treatment of juvenile delinquents is one of those issues on which all degrees of opinion exist.” The two examples of extreme opinions are the anchors while the remainder of the text constitutes the permissive introduction. The anchors are those reported by Weiss (1959). The permissive introduction and/or anchors were presented on a separate page preceding the communication, which was entitled “Dealing with Juvenile Delinquents.” By this procedure we hoped to clearly separate the introduction and anchoring treatments from the communication proper. (2) Communication plus permissive introduction (Comm $ PI): Subjects in this group (N = 42) were introduced to the communication with only the permissive introduction cited above, i.e., the examples (anchors) were omitted. (3) Communication plus anchors ( Comm f A) : Subjects in this group (N = 41) were introduced to the communication with the examples (anchors) from the introduction cited above without the permissive introduction material. (4) Communication only (Comm only) : Subjects in this group (N = 43) read the communication without a permissive introduction or anchors. All communication groups responded to a modification (for juvenile delinquents ) of the Wang-Thurstone scale on the treatment of criminals as they thought the communicator would respond. Subjects’ responses reflected whether the communicator would agree or disagree with each item on modified Form A. Following this rating, ::ubjects responded to a modification of Form B in terms of their own opinion. Three control groups received no communication and did not make judgments of the communicator’s position on juvenile delinquency: ( 1) Control No PI, No A. Members in this group (N = 42) just rated each statement on modified Form A along an 11-point scale in terms of its favorableness or unfavorableness to punishment of juvenile delinquents.’ Own opinion on treatment of delinquents was obtained from responses to modified Form B. ‘The purpose of having control subjects judge the Form A items was to provide them with experience over the same content as the communication groups, save fol the communication itself. The additional possibility that judgments of these items might prove useful in examining the operation of the permissive introduction and anchors was precluded by large variabilities in item judgments. Inspection of the patterns of judgment5 suggested that the large variabilities were due to the failure of slightly over half of the subjects to judge Form A according to the leniency and harshness of the items rather than agree or disagree with them. This was surprising
422
DILLEHAY
(2) Control rating the
+ items
PI. The
permissive
AND
BERGER
introduction
preceded
Form A of the modified (N = 41) expressed their own opinion on modified
on
(3) mod&xl
Control Form
Experimental
$ A. The two A. Own opinion
Pretest on the anonymous punitive given
Form B. embedded in the instructions on rating on modified Form B (N = 41).
anchors were was obtained
“criminal”
communication
indicated
that it was moderateIy
treatment of juvenile delinquents. to the communication was 10.2.
The Wang-Thurstone word
instructions
scale. Subject.;
Matetials
able toward average rating the
subjects’
Wang-Thurstone
from
with
scale on treatment
On
of criminals
a 19point
was modified
favor-
scale,
the
by replacing
“delinquent.”
Procedure Data were collected in group sessions, with the number per session ranging from 20 to 50. Booklets to each session.
containing Subjects
each were
of the seven treatments were randomly ordered told that they were participating in a study
of
prior the
judgment of other people’s opinions, and that the topic being considered was juvenile deknquency. It was pointed out that their responses were anonymous. The Wang-Thurstone scales were scored value of one and antipunitive responses a scored under this procedure and were deleted of the communicator’s position on punitiveness
and own opinion on punitiveness
by
assigning
propunitive
value of zero. Neutral from the is based
responses
a
items cannot be
following analyses. Judgment upon 18 items from Form A,
is based upon 17 Form B items. RESULTS
Judgment
of Communicator’s
Position
A preliminary 2 X 2 X 2 (permissive introduction X anchor X factorial analysis of variance for unequal N (unweighted means) computed to determine whether sex difference interacted with the ments. None of the relevant interactions were signifkant nor was
sex) was treatthere
a main effect due to sex. Data for males and females were then combined, and a 2 x 2 factorial analysis of variance for unequal N was performed (Table 1). Results of this analysis indicated that the main effect due to permissive introduction was significant (F = 3.92, 1 and 163 df, p < .OS), but that the anchoring manipulation was not. Individual comparisons between means (Table 2) were made using the t statistic suggested by Winer (1962, p. 244) for use with unequal KS. The Comm + PI + A group, which is analogous to Weiss’s (1958) original End Standards condition, attributed less punitiveness to the communicator than did the Comm Only group (t = 2.12, 163 df, p < .025).* to us since the judgment successfully used in prior ’ One-tailed test.
instructions to subjects studies by the first author
had been pretested elsewhere and with different college populations.
PERMWVE
I~ODU&ION
TO
TABLE ANALYSIS
OF VARIANCE
OF JUDGMENT
423
A COMMUNICA-~ION
1 OF COMMUNICATOR’S
Source
df
Anchors vs. no anchors (A) Permissive introduction vs. no permissive introduction AXB Within-cell error
MS
1
(B)
POSITION
1 1
163
13.76 51.30 .83 13.10
F
3.92*
* p < .05. TABLE MEAN
JUDGMENTS
Anchors No anchors
2
OF COMMUNICATOR’S
POSITION
Permissive introduction
No permissive introduction
11.44 11.86
12.39 13.12
The Comm Only group is analogous to Weiss’s No Standards condition. The Comm + PI group also judged that the communicator advocated a less punitive position than did the Comm Only group (t = 1.60, 163 rlf, p < .10).2 There was no difference in judgment of the communicator’s position between the Comm + A and the Comm Only groups. In an attempt to determine whether the manipulations affected the punitive items, the lenient items, or both, the beliefs attributed to the communicator in each of the communication groups were examined. These analyses showed that in the PI + A group there was a greater tendency to attribute lenient beliefs to the communicator and a lesser inclination to attribute punitive beliefs to him relative to the Comm Only group. That is, the locus of the effect for the PI + A group is in both the lenient items and the punitive items of the scale used to measure the perceived stand of the communicator. This analysis was done by using the sign test to compare the differences between proportions of agreement for the communicator in the two groups on lenient and punitive items on the Wang-Thurstone Form A scale. Considering the Comm Only vs. Comm + PI + A comparison, the number of punitive items on which a greater proportion of subjects in the Comm Only group agreed was significant ( p = .039) ; the number of lenient items with a higher proportion of Comm Only subjects disagreeing was significant ( p = .07). Combined the difference was highly sign&cant (p = .002). Comparable comparisons for the Comm Only and the Comm + PI groups showed the
424
DILLEHAY
effect on ence for None of proached
AND
BERGER
the punitive items to be significant ( p = .039), with no differthe lenient items ( p = .50) and items combined (p = .14). the comparisions involving Comm Only and Comm + A apsignificance.
Own Opinion The first of variance cant (F = groups (F
analysis of subject’s own opinion was a 2 x 7 factorial analysis for unequal N (Table 3). Main effects due to sex are signifi8.56, 1 and 277 df, p < .Ol) as are main effects for treatment = 3.25,6 and 277 df, p < .Ol). TABLE ANALYSIS
OF VARIANCE
Source
sex(A) Treatment groups (B) AXB Within-cell *p
error
~h'ISIOX
df
MS
F
1 6 6 277
36.07 24.31 2.71 6.55
8..56* 3.2.5*
< .Ol. TABLE MEAN
Males Females
3 OF OWS
OWN
OPINIOS
4
FOP, COMMUNICATION
Comm only
Comm +A
Comm + PI
8.50 6.79
7.40 6.27
7.08 6.13
AXD
CONTROL
GROTPS
Comm
Control
Control
Control, no PI,
+PI+A
+PI
+A
no A
.5.76 5.71
6.38 4.96
5.83 5.17
6.56 5.88
Individual comparisons between means were tested using the NewmanKeuls technique with the level of significance established at p < .05. The comparisons reported here are for marginal means, i.e., for treatment main effects rather than for simple main effects on males and females separately. The Comm Only group was significantly more punitive than the other communication groups and the controls. The Comm + A group held a significantly more punitive opinion than did the three controls. The Comm + PI group was also significantly more punitive than the three controls. No other means were significantly different from one another. A second analysis of own opinion was performed on scores from the four communication groups. A preliminary 2 X 2 X 2 factorial analysis of variance for unequal N established that none of the interactions asso-
PERMISSIVE
INTFiODUCI-ION
TO
425
A COMMUNICATION
ciated with sex approached significance. The sex main effect was significant. Table 5 shows the 2 x 2 factorial analysis of variance for unequal N computed on the combined male and female data. The permissive introduction main effect was significant at the .lO level (F = 3.56, 1 and 163 df). Ana~~srs
OF VARIANCE OF OWN
TABLE 5 OPINION FOR COMMUNICATION GROUPS
Source
Anchors vs. no anchors (A) Permissive introduction vs. no permissive introduction AXB Within-cell error *p
(B)
c1.f
MS
F
1 1 1 163
11.68 27.11 .83 7.62
1.53 3.56*
< .lO.
Individual comparisons between means (Table 6) were made using the t statistic suggested by Winer (1962, p. 244), The Comm + PI + A group, analogous to Weiss’s Ends Standards condition, expressed less punitiveness than did the Comm Only group, analogous to Weiss’s No Standards condition (t = 2.21, 163 df, p < .025).2 The Comm + PI group was also slightly less punitive in its opinion than the Comm Only group (t = 1.59, 163 df, p < .10).2 There were no differences in own opinion between the Comm + A and Comm Only groups ( t < 1). MEAN Owr
TABLE 6 OPINION FOR COMMUNICATION GROUPS Permissive introduction
Anchors No anchors
6.02 6.40
No permissive introduction 6.68 7.35
DISCUSSION
The results offer clear support for the hypothesis that a permissive introduction alters judgment of a persuasive communication that argues for a moderately extreme stand on a social issue. Anchoring, on the other hand, was found to be ineffective in bringing about a significant judgmental effect. With regard to consequences for opinions, the otherwise effective communication was rendered ineffective by the combination of variables of permissive introduction and anchors. Although the communication with either permissive introduction or anchors produced significant opinion change, this change was reliably less than the amount
426
DILLEHAY
AND
BERGER
produced by the communication alone. There was no suppon ror the notion that a permissive introduction or a set of anchors alone is sufficient to yield directly a change in opinion without the accompaniment of a communication. Permksive Zntroduction
as Context for a Persuasive Communication
One hypothesis that may account for the effects of a permissive introduction upon judgment of a persuasive communication can be referred to as a mood or atmosphere effect; a second possible interpretation concerns the salience of the variety of possible positions on the subjective scale of judgment. In either case the consequences should bc to reduce the perceived extremity of the stand advocated in the communication. The data presented here are not consistent with the idea that a permissive introduction to the issue in the absence of a persuasive communication has a direct impact upon opinions; or, if it does, the effects in this experiment are offset by changes in complementary directions by different subjects. If the permissive introductions operated directly upon opinions in a way consistent with either of the hypotheses just described, subjects in this study receiving the permissive introduction and no communication would have become less lenient in their advocated treatment of juvenile delinquents (from their somewhat lenient positions suggested by the control group’s position) because of either less discrimination along the scale of judgment or because of a more highly differentiated judgmental scale. Concerning the impact of the communication upon opinions about the treatment of juvenile delinquency, there was a marginally significant reduced impact due to permissive introduction alone with the communication, and a more significant outcome when anchors were utilized with the permissive introduction. These results fit the pattern of judgmental differences with the overall outcome that the less extreme the communicator was judged to be, the less change in opinion he brought about. These findings agree with that portion of the literature (e.g., Hovland and Pritzker, 1957; Weiss, 1958) that indicates greater change with greater discrepancies between the communicator’s position and the attitudinal positions of the communication recipients, and disagree with those findings that smaller discrepancies are more likely to produce change than larger ones (e.g., Hovland et al., 1957; Sherif and Hovland, 1961). A persistent problem with the reconciliation of these seemingly contradictory results is the distinction between emotionally involving and non-involving issues, which is suggested as the basis on which one can predict the amount of change likely to occur. For the present experiment the question would seem to be, is the treatment of juvenile delinquents it
PERMISSIVE
INTRODUCTION
TO
A
COMMUNICATION
421’
sufficiently involving issue for the subjects? The issue is probably less involving than prohibition or politics, which were studied by Hovland and his associates (see Hovland, 1959). An additional problem, of course, is the matter of the absolute discrepancies between the subjects’ positions and the perceived stand taken in the communications that are included in the study. Some difference is obviously required before change could be expected even with the most involving issue, and an extremely great discrepancy for even a non-involving issue may lead to rejection of the communication and to no effects upon opinions, or even changes opposite to the stand advocated by the communicator. The Use of External
Anchors with Persuasive Communications
With the clarification provided by the present study, we may conclude on present evidence that deliberately supplied external anchors in the fern? of examples of opinions that people hold on the topic of the communication are not effective in altering perception of the stand advocated in the commmlication. Previous negative evidence (Choo, 1964; Dillehay, 1965) and the explication and reinterpretation of Weiss’s ( 1958) findings as a consequence of the operation of a permissive introduction provide the basis for such a conclusion. It should be noted, however, that these studies have utilized opinion statements for anchors that contain a tone of reason in contrast to emotion. It is possible that emotional, inflammatory anchors might produce the predicted contrast effects. Other kinds of anchors in the communication situation, such as the invested position of the communicator as determined by previous knowledge (Dillehay and Lerner, 1968) or the attitudinal position of a significant person other than the communicator in the situation might be effective. While anchors alone did not yield effects, anchors in the form of opinion statements at the extreme positions on the scale did augment the effects of a permissive introduction, It seems plausible that the anchors supplement recall of opinion statements when the audience is induced to do so by a permissive introduction. An assumption concerning the utilization of this hypothesis to account for the differences between the impact of anchors and that of a permissive introduction is that the permissive introduction is more effective in evoking alternative positions on the judgmental scale than are anchors. The data from the present study present no support for the possibility that the use of external anchors in the form of examples of opinion extremes directly alter expressed opinions in the absence of an intervening communication. The findings of this experiment have interesting theoretical and prac-
428
DILLEHAY
AND
BERGER
tical consequences. The influence of a permissive introduction significantly modified the perceived position of the communicator and eliminated his impact upon the opinions of the audience. These consequences were even more pronounced when anchors were included with the permissive introduction. A curious paradox is contained in this kind of introduction. Using a permissive introduction one appears to be tolerant and fair, recognizing a variety of opinions on the issue at the same time he is neutralizing the impact of the communication to follow. REFERENCES BOCHNER, S., AND INSKO, C. A. Communicator discrepancy, source credibility, aud opinion change. Journal of Personality and Social Psychology, 1966, 41, 614-621. CHOO, TONG-HE. Communicator credibility and communication discrepancy as determinants of opinion change. Journal of Social Psychology, 1964, 64, 65-76. DLLLEHAY, R. C. Judgmental processes in response to a persuasive communication. Journal of Personality and Social Psychology, 1965, 1, 631-641. D~LEHAY, R. C., AND LERNER, M. J. Judgment of a persuasive communication as a function of recipient attitude, speaker, and message, Paper presented at the meeting of the Southwestern Psychological Association, New Orleans, April, 1968. HOVLAND, C. I. Reconciling conflicting results derived from experimental and survey studies of attitude change. American Psychologist, 1959, 14, 8-17. HOVLAND, C. I., HARVEY, 0. J., AND SHERIF, M. Assimilation and contrast eflects in reactions to communication and attitude change. Journal of Abnormal and Social Psychology,
1957, 55, 244-252.
C. I., AND PF~ITZKER, H. A. Extent of opinion change as a function of amount of change advocated. Journal of Abnormal and Social Psychology, 1957, 54,257-261. ROGERS, S. The anchoring of absolute judgments. Archives of Psychology, 1941, 37, No. 261. SHERIF, M., AND HOVLAND, C. I. Social judgment. New Haven: Yale University Press, 1961. SHERIF, M., TAUB, D., AND HOVLAND, C. I. Assimilation and contrast effects of anchor stimuli and judgments. Journal of Experimental Psychology, 1958, 55, 150-155. WEISS, W. The relationships between judgments of a communicator’s position and extent of opinion change. journal of Abnormal and Social Psychology, 1958, 56, 380-384. WEISS, W. The effects on opinions of a change in scale judgments. Journal of Abnormal and Social PsychoZogy, 1959, 58, 329-334. WINER, B. J. Statistical principles in experimental design. New York: McGraw-Hi]!. 1962.
HOVLAND,
(Received July 5, 1968)