back on the bandwagon: the effect of opinion polls on public opinion

Back on the Bandwagon: The Effect of Opinion Polls on Public OpinionAuthor(s): Catherine MarshSource: British Journal of Political Science, Vol. 15, No. 1 (Jan., 1985), pp. 51-74Published by: Cambridge University PressStable URL: http://www.jstor.org/stable/193747 .

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B.J.Pol.S. 15, no. I (I984), 51-74 Printed in Great Britain 51

Back on the Bandwagon: The Effect of Opinion Polls on Public Opinion CATHERINE MARSH*

The bandwagon was the caravan in a circus that carried the band, and usually took the lead in a procession. It has come to stand as a symbol for a party or a cause which is successful; we talk of people wanting to climb on to a bandwagon when their desire to be associated with the winning party or cause is strong. A 'bandwagon effect' is the label given by social scientists to a situation where the information about majority opinion itself causes some people to adopt the majority view for whatever reason; conversely, an 'underdog' effect is held to exist if the information causes some people to adopt a minority view. Processes of this kind are of theoretical interest because they affect the possibility of stable prediction in the social sciences; if the very act of predicting that one party will win an election can be a self-fulfilling prophecy1 then the natural scientific model of the social sciences may be compromised. Bandwagon processes are also of practical importance to pollsters, since the professional nature of their trade might also be compromised if their predictions could be shown to be interfering in political reality. These effects have therefore received a fair amount of attention in the literature. The main context studied has been the effect of exposure to an opinion poll on the general public. In this article, I shall first examine the existing evidence for poll effects of this kind, and then present and discuss a study of such effects.

I. PREVIOUS RESEARCH INTO THE EFFECT OF POLLS

The possibility of predictions affecting outcomes in the electoral arena has provided the meat for some elegant theoretical articles by political scientists.2

* Social and Political Sciences Committee, University of Cambridge. The research here was carried out with the support of SSRC grant no. E 230018. I am very grateful to Nigel Walker, Wolfson Professor of Criminology at the University of Cambridge, for giving me space on a survey of penal attitudes towards crime to conduct this experiment. Thanks are due to NOP Market Research Ltd., especially to Nick Moon, not just for carrying out the fieldwork for the research but also for advice and help throughout the survey, and for helpful comments on an earlier draft of this paper. Brian Omotani in the Computer Laboratory at the University of Cambridge gave invaluable technical advice. Others who have given advice or helped are: Bob Blackburn, David Calderbank and Colin Fraser.

1 R. K. Merton, 'The Self-Fulfilling Prophecy', Antioch Review, viii (1948), 193-21O; R. L. Henshel, 'The Boundary of Self-Fulfilling Prophecy', British Journal of Sociology, xxxIII (1982), 511-28.

2 H. A. Simon, 'Bandwagon and Underdog Effects in Election Prediction', in Models of Man: Social and Rational (New York: Wiley, I957), pp. 79-87; M. Gartner, 'Endogenous Bandwagon



















52 MARSH 52 MARSH 52 MARSH

However the empirical work that has been done to provide evidence for such processes has been scanty, and, where it has been performed has been rather restricted in its subject matter and uninspired in its research design.

There have been a handful of experimental studies where the researchers varied the information they gave to random groups of subjects about the current state of majority opinion before asking respondents their own opinion. Most of these come up with null or insignificantly small results.3 Similar null results are found in the widely cited four quasi-experiments which utilize the east-west time differences in the USA to explore the effect of hearing early returns from the east while polling continues in the west.4 Many of the investigators express surprise that they could not produce conformity effects with manipulation of this kind.

In fact, where an effect has been produced in experimental studies of voting behaviour, it suggests that polls encourage support for the underdog. In two studies, mock elections were set up, and subjects were given information about how others had voted before they were asked to vote again;5 under these very artificial conditions, there is some evidence that people tried to keep the loser, the underdog, in the running. Similarly, two experiments in Britain6 show that varying poll information can affect stated intention to vote in an

underdog direction; the supporters of the party behind at the polls say they are more likely to turn out to vote, and supporters of all parties say they are less likely to turn out if a clearcut victory persists. In the most recent study of this kind7 conducted on college students, evidence of fairly large underdog effects in voting intention in the I980 presidential election were produced;

and Underdog Effects', Public Choice, xxv (i976), 83-139; P. D. Straffin, 'The Bandwagon Curve', American Journal of Political Science, xxi (I977), 695-709; C. E. Zech, 'Leibenstein's

Bandwagon Effect as Applied to Voting', Public Choice, xxi (I975), 117-22. 3 H. F. Dizney and R. W. Roskens, 'An Investigation of the "Bandwagon Effect" in a College

Straw Election', Journal of Educational Sociology, xxxvi (I962), 108-14; R. Navazio, 'An

Experimental Approach to Bandwagon Research', Public Opinion Quarterly, XLI (1977), 217-25;

A. H. Cantril, ed., Polling on the Issues (Cabin John, Md.: Seven Locks Press, I980); J. L. Tyson and S. A. Kaplowitz, 'Attitudinal Conformity and Anonymity', Public Opinion Quarterly, xxxv

(1977), 226-34. 4 K. Lang and G. Lang, Voting and Nonvoting: Implications of Broadcasting Returns before

the Polls are Closed (Waltham, Mass.: Blaisdell, I968); H. Mendelsohn, 'Election Day Broadcasts and Terminal Voting Decisions', Public Opinion Quarterly, xxx (I966), 212-25; D. Fuchs, 'Election Day Radio-Television and Western Voting', Public Opinion Quarterly, xxx (I966), 226-236; S. Tuchman and T. E. Coffin, 'The Influence of Election Night Television Broadcasts in a Close Election', Public Opinion Quarterly, xxxv (1972), 315-26.

5 J. A. Laponce, 'An Experimental Method to Measure the Tendency to Equibalance in a Political System', American Political Science Review, LX (I966), 434-8; D. W. Fleitas, 'Band-

wagon and Underdog Effects in Minimal Information Elections', American Political Science

Review, LXV (1971), 434-8. 6 Rothman in F. Teer and J. D. Spence, Political Opinion Polls (London: Hutchinson

University Library, I973), pp. 131-2; G. Gaskell, 'Polls and the Voters', New Society, 4 April

1974, pp. 23-4. 7 S. J. Ceci and E. L. Cain, 'Jumping on the Bandwagon with the Underdog: the Impact of

Attitude Polls on Polling Behaviour', Public Opinion Quarterly, XLVI (1982), 228-42.





































Back on the Bandwagon 53 Back on the Bandwagon 53 Back on the Bandwagon 53

however, manipulation of the subjects' perception of the state of the polls was done twice in this rather complex and artificial study, and the main opinion shifts seemed to have occurred after the second treatment, a result that is very hard to interpret.

But neither the results of artificial, game-like situations nor the evidence of people's beliefs about causes of their behaviour is very convincing evidence for poll effects.

The non-experimental evidence that exists is open to a wide variety of interpretations. Beniger8 uses evidence from trends in the poll standing and success of candidates in state primary elections in the USA from 1936 to 1972 to advance a cautious 'glacial bandwagon' hypothesis: each report of the poll standing of a candidate does not in itself seem to influence his standing in subsequent polls, but the best single predictor of success in obtaining the Presidential nomination is the candidate's standing in the first poll. However, while this finding is consistent with the idea of a slow, cumulative effect, it is also consistent with many other explanations.

There is quite plausible evidence of an underdog effect in British election polling. In all the elections between 1959 and 1974, the poll predictions in the pre-election period are consistently above the final outcome. However, this could be a last minute anti-government rather than anti-winner decision on voters' part.9

Most importantly, the non-experimental cross-sectional evidence (as opposed to time-series data just discussed) cannot help resolve the crucial question of the direction of causal flow. Many studies have shown the correlation between personal opinions and perceptions of the opinions of others, but this could be the result of a psychological projection mechanism rather than of an opinion spiral. And, to repeat, we cannot treat it as evidence for the effect of poll information rather than the effect of information from other sources of public opinion.

As Campbell observed over thirty years ago, only experimental studies can hope to isolate the effect of publishing a poll result (195I). The field experiment that he proposed as a test of the bandwagon hypothesis involved selecting areas of America where no major newspapers carried syndicated public opinion services, modifying significantly the degree of knowledge of poll results in those areas, and monitoring the effects of this information over time; his proposal would have cost $75,000 in 1951. Such a full proposal forms a rich contrast to the studies that have been carried out; Campbell's, unsurprisingly, never was.

It is important, then, to establish whether the existing experimental studies

8 J. R. Beniger, 'Winning the Presidential Nomination: National Polls and State Primary Elections, I937-1972', Public Opinion Quarterly, XL (1976), 22-38.

9 See Catherine Marsh, 'Do Polls Affect What People Think?' in C. F. Turner and E. Martin, eds, Survey Measurement of Subjective Phenomena, Report of the Panel on Survey Measurement of Subjective Phenomena, National Research Council, National Academy of Sciences, 2 vols. (New York: Sage, I983)






















have produced null results because they are insufficiently sensitive in their design or because poll results really do not affect anybody. In general, the following criticisms can be advanced of the experimental and quasi- experimental studies cited in the literature:

I. The subject matter is almost exclusively on effects in election polls and ignores issue polls.

2. It is concerned with net, between-group effects, rather than with gross effects; it is possible that poll information could cause switching in different directions among subgroups.

3. It is concerned with effects on an undifferentiated electorate rather than on

particular groups for whom the information might be particularly important - the uncommitted, opinion leaders, those with a high desire for

approval and so on. 4. Attempts have not been made to control for an individual's prior beliefs

about majority views. This is a serious objection, especially in light of the robust finding in social psychology that it is surprising information that has most impact.10

5. The operationalization of the notion of a bandwagon is static rather than

dynamic; it is presumed that the current state of public opinion rather than the direction of change is influential.

6. All the studies are conducted within the 'persuasion' paradigm of media effects, rather than the 'agenda-setting' paradigm; to adapt the familiar cliche, it may be that the polls have their effect by telling people not so much what other people think as by giving an impression of what they think about.

An experimental study was therefore designed which tried to take most of these criticisms on board.

2. DESCRIPTION OF THE STUDY

In order to test whether poll information had any effect on individual

opinions, an experimental design was used where respondents were randomly assigned to one of four conditions. In two of these conditions, information about the results of current opinion polls was varied; in two, information about the trend of recent opinion polls was varied.

The subject matter chosen for the experiment was abortion. There were several reasons for this choice. Firstly, it is a subject about which it is reasonable to presume that crystallized public opinion exists; it therefore

provides a reasonably stringent test of the hypothesis that public opinion polls can themselves influence public opinion. In the bandwagon literature discussed in the last section, on the other hand, tests of the effect of polls were done on election decisions, and most of them tapped opinion far too late, at a point

10 H. R. Gollob, B. B. Rossman and R. P. Abelson, 'Social Inference as a Function of the

Number of Instances and Consistency of the Information Presented', Journal of Personality and

Social Psychology, xxvII (I973), I9-33.










































where a highly specific piece of behaviour, voting for a particular candidate, has been crystallized in a respondent's mind. Abortion does not fall foul of this criticism. It is much more multifaceted, as the range of answers to different questions demonstrates.1 Thus, secondly, the topic requires new thought when the question is put to the respondent. Moreover, for this same reason it is plausible to vary the information experimentally and tell people that public opinion is (or is becoming) either more or less restrictive.12

The third reason for choosing abortion was that there were good reasons to believe that a reasonably even-handed question on the topic could be devised. In small previous enquiries on student samples, we tested several forms of question-wording about abortion.13 We asked student samples if they could detect which side of the controversy had sponsored particular questions; they were able to do so correctly in almost all cases. One clear exception was a question where the majority of our student judges found it 'hard to say' which side commissioned it.

This seemed, therefore, an obvious question to use in the experiment. The question was modified slightly to read:

'In general, do you think the law should be left as it is, or should abortion be made easier to get, or should it be made more difficult to get?'

The questionnaire design was as follows. The questions came at the end of a forty-minute interview which was mainly about the unrelated topic of sentencing for petty crimes. It is arguable that the earlier questions may have biased responses by suggesting that abortion was a crime, but the results were not very different from recent studies using similar wording in a different context. All respondents were asked what they thought other people thought about changing the law on abortion.'4 Then they were asked in what direction they thought the trend of public opinion was going.15 Next, they were asked the question cited above, the main dependent variable. And finally they were asked how strongly they felt about the topic.16

11 Catherine Marsh and David Calderbank, 'Attitudes to Abortion i962-i982' (mimeograph, Social and Political Sciences Committee, University of Cambridge, I983).

12 In a pilot of seventy-one individuals we asked the interviewers to record if the experimental information was ever challenged, and it was on only one occasion.

13 Catherine Marsh, 'Judging Bias in Question Wording: A Research Note' (mimeograph, Social and Political Sciences Committee, University of Cambridge, I982).

14 'Do you think on balance that most people want the law left as it is now, or do they think that abortion should be easier to get, or do they think it should be more difficult to get?'

15 'In which direction do you think public opinion will move in the future? Will public opinion not change in the future, or will it move towards making abortion easier to get, or towards making it more difficult to get?'

16 We had an interesting degree of difficulty in the pilot study in devising a suitable measure of strength of feeling. We included a question after the main abortion question, saying simply: 'and how strongly do you feel about that?' The pilot interviewers reported that many people replied, 'About what?' Even with respondents who immediately gave a reply, many of them seemed to be answering a very vague question: 'How strong are your views on abortion?' The question was therefore modified in the main survey to read 'How strongly do you feel that the law on abortion should be ... left as it stands . . . the law should be altered (etc.)?' This worked much better.


























For the purposes of the experimental manipulation, the sample was divided randomly into four sub-samples of approximately equal size. The experimental manipulations were introduced into the survey at two slightly different points. Two subgroups were fed information about the supposed state of current public opinion immediately after they had said what they thought others thought, one subgroup being told that most people wanted abortion to be made easier, and the other subgroup that most people wanted it made harder.17 They were then asked the same question about trends and then their own opinion. The two other subgroups were asked what they thought others thought, then the question about trends, after which the experimentally varied supposed information on trends was given to them, one group being told the trend was towards abortion being made easier and the other harder.18 Then they were asked their own views. At the very beginning of the questionnaire there was a battery of items designed to tap authoritarian views in the family and legal arena. One of these questions was about abortion, and provided a useful control of people's view on abortion prior to the experimental manipulation.19

The device of asking people for their perceptions of public opinion before introducing the experimental manipulation was very successful in enabling the interviewer to tell respondents the supposed truth of the matter in a naturalistic manner while ensuring that the respondent's attention was focused on it. The interviewers were all personally briefed and sensitized to the importance of getting this information across clearly and convincingly but not in an over-obvious fashion; it seemed likely that in some of the previous research of this type the experimental information was simply missed by the respondents.

The universe sampled was that of parents with children under the age of twenty living at home. The survey was carried out in three English towns, selected as a contrast to one another, St Helens, near Liverpool, Basildon in Essex and Solihull in the West Midlands. The method of selection was a quota sample, with controls set on age, sex and working status, based on information derived from national random surveys conducted by NOP Market Research Ltd. (Polls). Interviewing was conducted in all wards of each constituency. A major degree of control over social class was also achieved by specifying small areas within the wards in which each interviewer was to work. A total of I,055 interviews was conducted, and the number of refusals before these were obtained was 990.

The enquiry was an experiment, not a passive observation programme. Therefore the most important design feature was not the representativeness

17 'In fact most people want abortion to be made easier/harder to get. 18 'In fact the trend in recent polls has been towards making abortion easier/harder to get.' 19 'Abortion should be legally available for anyone who wants it' - 'Strongly agree ... agree

... neither agree nor disagree ... disagree ... disagree strongly.'















Back on the Bandwagon 57

of the sample (whatever that means - see Kruskal and Mosteller)20 but the success of the random assignment process. To check that the result of the random allocation had not been to produce chance differences in the distribution of variables between versions, significance tests were performed on the association between each version and every demographic and attitudinal variable that we had not consciously tried to manipulate, including the earlier abortion item. Out of forty-two such variables only one (how severe a sentence individuals thought that a suspended prison sentence was) produced significantly different replies in each version at the io per cent level (p = 0.07).21 We can therefore conclude that the randomization was successful.

In order to describe the results succinctly, we shall use some short-hand ways of describing particular views. We shall refer to those who thought the law should be changed to make abortion easier to get as 'permitters', to those who thought it should be changed to make it more difficult to get as 'restricters', and to those who thought it should not be changed as 'non- interventionists'. With the earlier abortion question (text in footnote I9) we shall call people who endorsed the view 'pro-abortionists', those who rejected it 'anti-abortionists' and those who could neither agree nor disagree 'indecisive'; this terminology is not satisfactory, as it is doubtful whether anyone believes abortion to be a good thing, but I hope that misunderstand- ings will not rise from these abbreviated descriptors.

3. PROFILE OF NON-EXPERIMENTAL RESULTS

Before we consider the result of the experiment, some non-experimental findings will be presented, but it is important to remember that they have been derived by grouping together all four experimental groups and ignoring the treatments they were given.

There is no doubt that people notice public opinion polls. Seventy-seven per cent of the sample claimed to be aware of poll results either on television, radio or in the papers. This is slightly less than a similar result reported by Bowen22 where 84 per cent of the sample claimed to have noticed or heard about polls of voting intention, and somewhat more than the two-thirds who usually claim during an election campaign to be aware of the state of the polls.23 This high degree of awareness is not surprising, given the density of

20 W. Kruskal and F. Mosteller, 'Representative Sampling I, II and III', International Statistical Review, XLVII (I979), I3-24, III-27, 245-65.

21 Note that, since survey variables correlate with one another and are not independent, we would not, pace Selvin and Stuart (H. C. Selvin and A. Stuart, 'Data-dredging Procedures in Survey Analysis', American Statistician, xx (I966), 20-3), expect to find one in ten producing differences significant at the o-I level across randomized conditions.

22 Jenifer Bowen, 'A Survey of the General Public's Attitudes to Market Research', Journal of the Market Research Society, xxl (1979), 75-102.

23 NOP Market Research Ltd., NOP Political Bulletin, No. 124 (I974a); No. I3I (I974b); Market and Opinion Research International, British Public Opinion: General Election 1983: Final Report (MORI, 32 Old Queen Street, London SWIH 9HP).
























TABLE I Perception of Current Views by Perception of Trends*

Do you think on balance In which direction do you think public opinion will move that most people want the in the future? law changed to make More abortion...? Easier No change difficult Total (N)





Easier Left as it is More difficult



74'9 54-8 48.6

74'9 54-8 48.6

74'9 54-8 48.6

13'9 28.7 14'9

13'9 28.7 14'9

13'9 28.7 14'9

II-2 27.6 (267) I6-5 53'7 (520) 36-5 I8-7 (i8i)

II-2 27.6 (267) I6-5 53'7 (520) 36-5 I8-7 (i8i)

II-2 27.6 (267) I6-5 53'7 (520) 36-5 I8-7 (i8i)

Total. 59-2 22-0 I8-8

* Row percentages; taub = 0-20; p = -00ooo; missing observations = 87.

TABLE 2 Joint Distribution of Two Abortion Questions*

Abortion should be In general, do you think the law should be changed to legally available for make abortion? anyone who wants it Left as More

Easier it is difficult Total (N)

Agree strongly 65.2 31.8 3-0 65 ( 66) Agree 43'8 46-4 9'7 49'3 (504) Neither I8.8 44.9 36.2 6-7 (69) Disagree 6-o 40-0 54'0 27'9 (285) Disagree strongly 3-4 I2.6 83'9 85 ( 87)

Total 29'4 40'7 30'0

* Row percentages; taub = 0-52; p = o0ooo; missing observations = 44.

Total. 59-2 22-0 I8-8






Total 29'4 40'7 30'0


Total. 59-2 22-0 I8-8






Total 29'4 40'7 30'0


reporting coverage that polls receive.24 Our sample had no difficulty in

expressing a view on either the current state of public opinion on abortion (5 per cent declined a view) or on trends (only 4 per cent declined a view).

Table I shows the joint distribution of the answers to the two questions about respondents' perception of public opinion. Looking at the final column

(the row marginals), it is clear that most people (54 per cent) believe that others are non-interventionist. The remainder are more likely to think that others are permissive than to think they are restrictive. The distribution of perceptions of trends in public opinion, shown in the bottom row (the column

marginals) of Table I, shows a striking 59 per cent who believe that the public is becoming more permissive. However, the degree of association between the two variables is not complete; 49 per cent of those who believe public

24 It has been estimated that there is, on average, at least one poll finding in every newspaper issued in Britain and the USA (Turner and Martin, Survey Measurement of Objective Phenomena, Chap. 2.). MORI calculates that 4 per cent of the front page news coverage in the

I983 general election was devoted to opinion polls (Market and Opinion Research International Ltd. General Election I983, Appendix I).


















TABLE 3 Perception of Others' Views by Own Views*

Do you think on bal- In general, do you think the laws should be changed ance that most people to make abortion ...? want the law changed Left as More to make abortion .. .?t Easier it is difficult (N)

Easier 56-3 Ig9o 24.6 (268) Left as it is I8-7 57'3 24'0 (524) More difficult 18-7 24'7 56'6 (182)

In which direction do you think public opinion will move in the future?t

Easier 37.5 37'7 24-8 (589) No change 13-7 59'7 26-5 (2I) More difficult I6-7 317 5I16 (I86)

* Row percentages. t Tau, = 0-29; p = 0-000; missing observations = 8I. t Tau, = 0-23; p = 0-000; missing observations = 69.

opinion at present to be restrictive believe that it will move in a permissive direction.

The views of our sample, both on the earlier abortion item and on the main

dependent variable, are shown in Table 2. Looking first at the bottom row, (the column marginals), we can see that 41 per cent wanted the law left, 29 per cent wanted it changed to make abortion easier to get and 30 per cent wanted it changed to make abortion more difficult to get. The final column (the row marginals) of the table show the predisposition of our sample to

agreeing with the availability of abortion to everyone. The cells inside the table validate the 'easier' and 'more difficult' categories as pro- and anti- abortion positions respectively, but also show the complexity of views about leaving the law as it is. Forty-five per cent of pro-abortionists thought the law should be left, but so did 34 per cent of anti-abortionists. Non-interventionists probably include cautious Popperians, would-be permitters who fear re-opening a can of worms, would-be restricters who think the application of the law could be improved, those who are not prepared to admit that they have not thought about the topic and so on. However, the fact that more pro-abortionists than anti-abortionists thought the law should be left probably means that the current law is perceived as permissive. This is important to remember when looking at the experimental results that follow.

There is, of course, a strong association between personal views on abortion and perception of others' views on abortion. Table 3 shows the effect of the views of others on personal views.25 People tend to think that other people think like them now, and, to a lesser extent, they believe others will tend towards their own view in the future.

25 The percentages have to be run in this direction since the perception variable was manipulated among subgroups on the assumption that the direction of cause was from perception of others to own views.




























TABLE 4 Comparison of Attitudes to Abortion with National Sample*

Abortion should be made legally available for anyone who wants it.

Agree Disagree strongly Agree Neither Disagree strongly (N)

Our sample 6-4 49'9 7'2 28-I 8-5 (I,055) National sample 9-2 43.9 IO.I 27'4 9'5 (I,9II)

* Row percentages; missing observations: our sample = I6, national sample = 88.

The column marginals of Table 2 are indicative of the state of public opinion in our three towns, but they might differ from the view of the general public in Britain, and our sample may have been responding about the national picture. We are fortunate to have access to some data from a quota sample drawn by NOP Market Research Ltd. in June 1982 to be representative of the adult population of Great Britain, in which the same battery of authoritarianism items as we included in our survey was administered.26

As can be seen from Table 4, while our sample is marginally less happy about expressing 'strong' views, in general the profile of responses is similar. Let us therefore treat the column marginals of Table 2 as the true state of public opinion, and compare them with the perceived state of public opinion, the row marginals in Table I. Although there is no overall majority in any one category in the column marginals of Table 2, the largest proportion did want the law left as it is, so the 54 per cent who believed in general that the public was non-interventionist could consider themselves to have been vindicated. Similarly, the permitters do outnumber the restricters, just as those who believe the public to be permissive outnumber those who believe it to be restrictive.

It is much more difficult to assess whether our sample is correct in its

perception of trends; we cannot do that on the basis of this survey alone. In a

study of responses to opinion polls on abortion between I965 and I982, it has been shown that there have been no consistent or large changes in either

general attitudes to abortion and the law on abortion, or in attitudes to the

availability of abortion under differing circumstances.27 Opinion is as stable in the most recent past as it is over the whole period, so it is interesting that the respondents in our sample were so sure that there would be a permissive trend in the future. It is theoretically possible that respondents believed that the trend in the future would be different from the trend in the past, but it is more likely that they misperceived the trend in the past. Misperceptions of the trend of public opinion will raise questions for us later on about the

generalizability of the experimental results to the real world. Given that the trend in opinion is perceived to be permissive, are the

restricters frightened away from stating their views strongly, as one theory of 26 I am very grateful to NOP Market Research Ltd for making this available. 27 Marsh and Calderbank, 'Attitudes to Abortion 1962-1982'.































Back on the Bandwagon 6I Back on the Bandwagon 6I Back on the Bandwagon 6I

TABLE 5 Attitude to Law by Strength of View*

How strongly do you feel In general do you think the law should be changed to make that...? abortion...?

Left as More Easier it is difficult (N)

Very strongly 24-2 24'5 51.3 (380) Fairly strongly 32.4 46-4 2I-2 (478) Not at all strongly 30-3 63'8 5'9 (152)

* Row percentages; taub = o024 p = o-ooo; missing observations = I6.

public opinion formation might lead us to predict?28 On the contrary, Table 5 shows that it is the restricters who say they feel most strongly about the current state of the law.

This is fully consistent with findings from a range of social issues of a liberal/conservative kind researched in the United States; the conservatives on many issues including abortion hold their views with more expressed passion than the liberals.29 Moreover, our measure of attitude strength seems valid, since people who want to change the law in either direction feel more strongly about the issue than those who want the law left as it is.

However, some further clarification of the concept of attitude strength is required. Schuman and Presser distinguish between different dimensions of attitude strength - between centrality (the importance of an issue to an individual), intensity of feeling about that issue and the likelihood of behaviour resulting from the attitude.30 On this classification, the question about attitude strength used in this study would be an intensity measure. However, one might assume that there should be an element of tenacity, a propensity to hold on to one's attitude, in any measure of strength of feeling; we shall call that into question when we come to the experimental results in the next section.

The demographic profile of abortion attitudes contained few surprises. The most important predictor of attitudes to the law is religion. Denominational affiliation discriminates well between permitters and restricters, but only among members of non-Christian religions (where N= 6) is a majority restrictive; 46 per cent of Catholics, 26 per cent of members of the Church of England and I9 per cent of atheists are restrictive. A simpler and stronger discriminator is religious attendance; among those who attend a service at least once a week, 6I per cent are restricters, whereas among the rest only 26 per cent are restricters, and this strong effect holds up within each denomina-

28 E. Noelle-Neumann, 'The Spiral of Silence: A Theory of Public Opinion', Journal of Communication, xxxiv (1974), 43-51.

29 H. Schuman and S. Presser, Questions and Answers in Attitude Surveys (New York: Academic Press, 198I).

30 Schuman and Presser, Questions and Answers in Attitude Surveys, Chap. 9.




























tion. Men are more favourably inclined towards abortion than women; they are consistently more permissive and non-interventionist, while women are more restrictive. The sex differential is strongest among the semi-skilled and unskilled manual workers, where I7 per cent more women than men hold restrictive views. Age does not affect the restrictive category at all, but io per cent more young people than old favour making the law permissive; correspondingly, the old prefer to leave the law as it is.

4. EXPERIMENTAL RESULTS

We now turn to the results of the experimental manipulations. The ex-

perimental variation of information about poll trends was shown to have a

strong and significant effect on the respondent's own view, whereas the static information seemed to have little effect. We shall therefore consider first the

subgroup of 527 people in the experiment on trends.

4. I Varying Trend Information

The overall results of the experimental manipulation of responds' perception of trends in public opinion about abortion are shown in Table 6. Before

considering them, a word of explanation about the method of analysis and

presentation is required. In this and subsequent tables, the percentages in each treatment group (i.e. those who were told that the trend was towards

making abortion easier or harder to get) who responded to each category of the main dependent variables (own attitude to the law on abortion) are shown. The percentage of those told the trend was restrictive are subtracted from the percentage told it was permissive, and the resulting differences (d) are shown in bold print underneath; the value of d therefore indicates the

effect of being told that the trend is permissive as opposed to being told that it is restrictive on personal attitudes to the law. Thus, for example, the - I 6 in the third column of Table 6 indicates that I I 6 per cent fewer of those who were told that the trend was permissive than those told the trend was restrictive believed abortion should be made more difficult to get.

The percentage difference (d) is the measure we shall use to assess the

strength of effect. All three percentage differences in any one row must cancel each other out; the I .6 per cent fewer restricters among those who were told the trend was permissive are balanced out by 9-I per cent more permitters and 2-5 per cent more non-interventionists. We shall therefore use the largest d in any one row, whether it happens to be positive or negative, to indicate the overall strength of the association between our experimental manipulation and the dependent variable.31 This will be important in the following tables where we examine which subgroups exhibit the strongest effects.

Since the overall experimental result is highly significant (at the I per cent 31 When there are only three categories, the largest percentage difference is also the index of

dissimilarity.
















dissimilarity.
















dissimilarity.




TABLE 6 Effect of Trend Information on Attitude to the Law*

In general, do you think the law should be changed to make aborition ...?

Experimental Left as More condition Easier it is difficult (N)

Told that trend was permissive 34'5 39.6 25'9 (255) Told that trend was restrictive 25-4 371I 37.5 (256) d= + 9-I + 2-5 - I-6

* Row percentages; tau, = 0-12 p = O-OOI; missing observations = i6.

level), we need not worry that the results are a fluke of the randomizing process. When we proceed to explore how this finding arose, further significance tests will not be performed. Such tests could be misleading, since insignificance would most likely occur because of small subgroup sizes, not because of the weakness of the association; as we shall see, the strength of effect in certain subgroups is quite striking.

Table 6 shows that 9 per cent more people express a permissive view and 3 per cent more say they want no change in the law when they are told that public opinion is moving in a permissive as opposed to restrictive direction; conversely, 12 per cent fewer people express a restrictive view. Having history (or rather the future) on your side seems to be an important dimension of bandwagon thinking.

Furthermore, the fact that the effect of a permissive trend is split between encouraging a directly permissive view and a non-interventionist view confirms what we inferred from Table 2; on balance, people see the current law as permissive.

However, a much clearer picture emerges, and a more sensitive experimental result is obtained, if we split the sample up into groups on the basis of their answers to the question on abortion which was contained in the attitude battery earlier in the questionnaire. Table 7 shows the experimental results within each subgroup of prior attitudes.

Several interesting things emerge from this elaboration. In general, the effects of being told that the trend is permissive as opposed to restrictive (differences of percentages in bold print) are all positive on the 'easier' response and negative on the 'more difficult' response, which is what we would expect. The exception are the IO per cent more restricters among those who agreed strongly with the prior abortion question when they were told the trend was permissive as opposed to restrictive; we might have expected this figure to be zero, but the size of this subgroup is small (N = 26), and it would therefore only take one capricious individual to produce this result.

There is also a clear pattern in the effects on the 'left as it is' response. Among those who 'strongly agree' and to a lesser extent among those who 'agree', the effects are negative, but among the indecisive, and increasingly those who 'disagree' the effect is positive. Among pro-abortionists, the effect


























TABLE 7 Effect of Trend Information on Attitude to the Law: Broken Down by Prior Attitudes*

Abortion should In general, do you think the law should be be legally avail- changed to make abortion ...? able for anyone who wants it. Experimental Left as More

condition Easier it is difficult (N)

Agree strongly trend permissive 70-0 20-0 IO-0 (I0) trend restrictive 62-5 37.5 o-o (I6) d= + 7'5 -I7'5 +Io0o

Agree trend permissive 50-0 4I-0 9-o (134) trend restrictive 40-7 45.5 I3.8 (123) d= + 93 - 45 - 48

Neither trend permissive 30-0 40-0 30-0 (20) trend restrictive I4.3 38'1 47-6 (21) d = +15'7 + I19 -17-6

Disagree trend permissive 11.4 41.4 47.I (70) trend restrictive 2-8 32.4 64.8 (71) d= - 8-6 + 90o -I7-7

Disagree trend permissive 30-0 70-0 (20) strongly trend restrictive 4.3 95-7 (23)

d= +25-7 -25-7

* Row percentages; missing observations = 19.

of a permissive trend is mainly to push people from non-interventionist positions into permissive positions, whereas among anti-abortionists, the effect is to push them from restrictive positions into non-interventionist ones. This highlights a different interpretation of one category of the dependent variable among different subgroups in the population; the more anti-abortion one is, the more permissive one perceives the current law to be.

The second interesting feature of this table is that we have shown a differential effect depending on prior views. Notice that the effect on each of the subgroups is, in general, stronger than the effect overall. Controlling for prior views does indeed increase the sensitivity of the experiment; the strength of the effect in the overall experiment seems lower because it disguises effects in different directions upon those who believe the law should be left as it is. Studies that fail to measure prior orientations before the experimental treatment are relatively crude tests of the bandwagon hypothesis.

The indecisive ('neither agree nor disagree') are fairly strongly affected. This finding is unsurprising; Lazarsfeld, Berelson and Gaudet,32 who provide the first major discussion of election bandwagons, believed that the undecided would be the most susceptible. The criticism that was levelled against the

32 P. F. Lazarsfeld, B. R. Berelson, and H. Gaudet, The People's Choice (New York: Duell, Sloan and Pearce, 1944).









d= +25-7 -25-7














d= +25-7 -25-7









TABLE 8 Effect of Trend Information on Attitude to the Law: Broken Down by Attitude Strength*

In general, do you think the law should be changed to make abortion ...?

How strongly do Experimental Left as More you feel that ...? condition Easier it is difficult (N)

Very strongly Trend permissive 29.4 28-2 42.4 (85) Trend restrictive I7'3 21-2 6I-5 (104) d= +12-1 + 7-o -I9-I

Fairly strongly Trend permissive 36-3 43'5 20-2 (124) Trend restrictive 28-9 46-5 24-6 (114) d= + 74 - 30 - 4'4

Not at all Trend permissive 35-7 54-8 9'5 (42) strongly Trend restrictive 40-0 51.4 8-6 (35)

d= - 4'3 + 34 + o09


previous bandwagon experiments was that they looked for effects after attitude crystallization had taken place. But the undecided are not the most powerfully affected group; the strength of effect among those who 'disagree', 'neither agree or disagree' and 'strongly agree' is about the same. Ironically, it is those who agreed with our statement but not strongly who are the most impervious to the effects of information about trends. (The image of the mild liberal as a 'trendy' is obviously quite wrong; this group appears most personally secure in its views!) But the most powerful effect is on those who 'strongly disagree' with the liberal abortion statement; 26 per cent more of them express a restrictive view if they are told the trend is restrictive. Those who 'strongly agree' are also fairly powerfully affected. The Ns are small, but it does seem that people who feel strongly are more powerfully affected by the trend information.

In order to check this interpretation, we repeated the analysis on subgroups created by our later attitude strength measure. Table 8 shows the effects first among the zealots who said they felt very strongly, then among those who felt fairly strongly, and finally among the Laodicians,33 who said they did not feel at all strongly. This confirms the interpretation about strength of feeling in Table 7; the largest d is 19 per cent among the zealots, 7 per cent among those who feel fairly strongly and 4 per cent among the Laodicians. It also suggests that not feeling strongly is different from being indecisive, since the indecisive group in Table 7 were fairly powerfully affected.

This must force some reconsideration of what simple measures of attitude strength pick up. One thing is clear: they do not measure what we earlier called tenacity - preparedness to stick to one's views in the face of pressure;







d= - 4'3 + 34 + o09











d= - 4'3 + 34 + o09





33 Revelations, 3: 15. 33 Revelations, 3: 15. 33 Revelations, 3: 15.




TABLE 9 Effect of Trend Information on Attitude to the Law: Broken Down by Perception of Trends

In which direc- In general, do you think the law should be tion do you think changed to make abortion ...? public opinion will move in the Experimental Left as More future? condition Easier it is difficult (N)

Easier Trend permissive 39'0 40'4 20-5 (146) Trend restrictive 33'8 35'7 30'5 (154) d= + 5'2 + 47 -IO-O

No change Trend permissive 25-0 56-3 I8.8 (48) Trend restrictive 3.9 49'0 47.I (51) d= +21II + 73 -28-3

More difficult Trend permissive 25'5 25'5 48'9 (47) Trend restrictive 14'3 33'3 52.3 (42) d= +112 - 78 - 35


quite the opposite, in fact. Perhaps one important part of preparedness to

express strong views is the perception that popular opinion is moving in your direction; to shatter that view has more effect on those it matters more to.

Perhaps a process akin to the Freudian idea of denial is operating, and it is

people who feel most unsure of what they think who say they feel the

strongest; this hardly constitutes an explanation, however. Or it might simply be that those who do not care enough about the issue to say that they feel

strongly also do not care what other people think about it. Another major criticism mounted against the existing bandwagon literature

was that there was no attempt to measure what people thought was the current state of public opinion, and that therefore we could have no idea whether the information presented was surprising to people. Table 9 shows the results of the experiment, first among those who believed public opinion to be moving in a permissive direction, then among those who thought it not

moving, then among those who saw it moving in a restrictive direction. Our hypothesis was that the effect would be most powerful on those who

were surprised by the information fed to them. The group that could perceive no trend contained the largest number of surprised individuals and it does indeed exhibit a much stronger effect than the other two groups where only half the respondents had their perception of trends shaken. The increased

power of surprising information may even lie at the root of explaining why it is information about trends rather than information about static public opinion that is most powerful; one could argue that a trend of any sort is, in some ways, surprising. At any rate, researchers who wish to demonstrate the effect of a communication of information must strive to situate the information they are presenting within the wider picture of the individual's cognitive frame of reference.




































We saw in Table 3 that there is a strong correlation between what people believe themselves and what they think other people believe. Although the case bases now become small indeed, we can obtain some suggestive results by looking at the results broken down by both prior view (as in Table

7) and by perception of the trend (as in Table 9). Table Io allows the identification of different subgroups: those who confidently believed the trend of public opinion was towards their own views (top right and bottom left); those who gloomily believed it was moving away from their own views (top left and bottom right); and those who at least saw no immediate prospect of public opinion coming into line with their own views (middle two groups). There were so few indecisive respondents to the early abortion question that they have had to be omitted from this table. It seems that the information given to the confident groups rolled straight off them, while the information given to the other, possibly insecure groups produced consistently powerful bandwagon effects.

In order to see this pattern more clearly, we can estimate the total number of steps that people are 'pushed' away from the category most consistent with their prior views on abortion towards one more consistent with the trend information we gave them; Table II summarizes this. To see how the calculations for Table I I were performed, consider the anti-abortionists who previously thought the trend was to make abortion easier. Looking at the differences of percentages in bold print in Table 10, we argue that the Io-6 per cent who said 'easier' would have to move two steps to the right to adopt the restrictive position, and the I9-4 per cent 'left as it is' would have to move one; 2(10.6) + I9-4 = 40-6. Table i summarizes the net movement in a band-

wagon direction; if we make the reasonable assumption that people only move one step, then it also tells us the percentage of people pushed in this direction. This way of looking at the figures draws inescapable attention to the effect of the information on those who, we argued, were already insecure. Among the secure there is a suggestion of a kick-back effect, but is probably safer to treat it as insignificantly small.

It is a pity we did not have a no-information control group to tell us which of the two groups (those who had their fears confirmed or their personal views surprisingly vindicated) moved the most.34 Some suggestive evidence can, however, be gained by considering the average scores of the other five hundred people in the experiment where current opinion was varied, as shown in Table 10. If this group can be treated as providing evidence of the baseline from which the trend information moved people, it would appear that both these groups moved fairly equally.

The only demographic variable that produced strong differential effects was age. The young (those under 34) were much more powerfully affected by the trend information than either the middle-aged or the old; once into middle age, people seem to care much less about what other people think. There

34 The design of four experimental groups was not drawn up for the experiment on abortion

attitudes, and this was the most efficient way to use the four groups available.



















TABLE I0 Effect of Trend Information on Attitudes to the Law: Broken Down by Prior View and Perception of Trends* TABLE I0 Effect of Trend Information on Attitudes to the Law: Broken Down by Prior View and Perception of Trends* TABLE I0 Effect of Trend Information on Attitudes to the Law: Broken Down by Prior View and Perception of Trends*

In which direction do you think public opinion will move in the future?

Easier


Easier


Easier

In general, do you think the law should be changed to make abortion ...? In general, do you think the law should be changed to make abortion ...? In general, do you think the law should be changed to make abortion ...?

Anti-abortionistst Anti-abortionistst Anti-abortionistst

Experimental condition

Trend permissive Trend restrictive d=


Trend permissive Trend restrictive d=


Trend permissive Trend restrictive d= Controlt

No change Trend permissive Trend restrictive d= Control

Controlt


Controlt


More difficult More difficult More difficult Trend permissive Trend restrictive d= Control

Trend permissive Trend restrictive d= Control

Trend permissive Trend restrictive d= Control

Left as More Easier it is difficult



I4'3 3'7

+ io-6

9'4

8-3 0-0

+ 8-3 2-5

I4'3 3'7

+ io-6

9'4

8-3 0-0

+ 8-3 2-5

I4'3 3'7

+ io-6

9'4

8-3 0-0

+ 8-3 2-5

49'0 29-6

+19-4 35'4

41'7 21-7

+20'0

55'0

I3.6 20-0

- 64 I7.0

49'0 29-6

+19-4 35'4

41'7 21-7

+20'0

55'0

I3.6 20-0

- 64 I7.0

49'0 29-6

+19-4 35'4

41'7 21-7

+20'0

55'0

I3.6 20-0

- 64 I7.0

36-7 66-7

-30'0 55'2

50-0 78-3

-28-3

42'5

86-4 80o-

+ 6-4 83-0

36-7 66-7

-30'0 55'2

50-0 78-3

-28-3

42'5

86-4 80o-

+ 6-4 83-0

36-7 66-7

-30'0 55'2

50-0 78-3

-28-3

42'5

86-4 80o-

+ 6-4 83-0

Pro-abortionistst Pro-abortionistst Pro-abortionistst

Left as More (N) Easier it is difficult



(49) (54)

(96)

(12) (23)

(40)

(22) (15)

(47)

(49) (54)

(96)

(12) (23)

(40)

(22) (15)

(47)

(49) (54)

(96)

(12) (23)

(40)

(22) (15)

(47)

53-6 53'3

+ 03 55'4

34'4 9.1

+25'3 21-9

52'4 25-0

+27'4 34'2

53-6 53'3

+ 03 55'4

34'4 9.1

+25'3 21-9

52'4 25-0

+27'4 34'2

53-6 53'3

+ 03 55'4

34'4 9.1

+25'3 21-9

52'4 25-0

+27'4 34'2

35'7 37-8

- 2'I

39'0

62.5 77'3

-14.8 -I4'8 71'9

33'3 50-0

-I647 47'4

35'7 37-8

- 2'I

39'0

62.5 77'3

-14.8 -I4'8 71'9

33'3 50-0

-I647 47'4

35'7 37-8

- 2'I

39'0

62.5 77'3

-14.8 -I4'8 71'9

33'3 50-0

-I647 47'4

I0-7

8-9 + I-8

5.6

3'1 I3'6

-I0-5 6-3

14'3 25-0

-Io 7 I8.4

I0-7

8-9 + I-8

5.6

3'1 I3'6

-I0-5 6-3

14'3 25-0

-Io 7 I8.4

I0-7

8-9 + I-8

5.6

3'1 I3'6

-I0-5 6-3

14'3 25-0

-Io 7 I8.4

(N) (N) (N)

(84) (90)

(I77)

(32) (22)

(64)

(21) (20)

(38)

(84) (90)

(I77)

(32) (22)

(64)

(21) (20)

(38)

(84) (90)

(I77)

(32) (22)

(64)

(21) (20)

(38)

* Row percentages.

t Abortion should be legally available for anyone who wants it: (anti-abortionists are those who 'disagreed' or 'strongly disagreed': pro-abortionists are

those who 'agreed' or 'strongly agreed'). t Control groups: Those whose perception of trends was not manipulated. Note: This table contains a lot of information and is best read as the result of six separate experiments like Table 6; in the top left-hand corner is the result

for anti-abortionists who thought the trend was towards abortions getting easier, in the top right is the result for pro-abortionists who thought the trend was

towards abortions getting easier, etc.

* Row percentages.





* Row percentages.





2

cn x

>! 3o

2

cn x

>! 3o

2

cn x

>! 3o

I I I




TABLE I I Total Bandwagon Effect (Summary of Table Io)

Anti-abortionists Pro-abortionists

Easier 40-6 - 1.5 No change 36-6 35.8 More difficult - 6-3 38-I

TABLE 12 Effect of Current Information on Attitudes to the Law*

In general, do you think the law on abortion should be changed to make abortion ...?


Told public opinion permissive 30-2 41.I 28.7 (258) Told public opinion restrictive 26-4 45'3 28-3 (254) d= + 3-8 - 42 + o4

* Row percentages; taub = 0.02; p = 0-3o; missing observations = I8.

were no differential effects by sex or class or among those with differing degrees of education.

4.2 Varying Current Public Opinion

In contrast to the results shown in the last section, Table 12 shows that presenting respondents with information about the current state of public opinion had inconsistent and insignificant effects. The bandwagon has to be moving before people want to get on it. Tables comparable to those shown in Section 4. were constructed for the groups given information about current public opinion, and in no case did they produce significant results.

However, we must not rush to conclude that static information has no effect. It may be that the design of the questionnaire inhibited picking up this effect. As was explained earlier the experimental information about trends was presented directly before the main dependent variable, whereas the information about current public opinion came before this. The 530 respondents in this second experiment had the interference of the question about trends before getting a chance to express their own views. It may be that this prevented us picking up an effect. One finding might encourage this interpretation of our null results. The treatment in the second experiment did produce an effect on the interfering variable, perception of the trend (Table I3).

As we would expect, the effect is stronger when we control for what the respondent believed was the state of current public opinion prior to our manipulation (not shown here). This is unremarkable. People who 'discover' that they have a mistaken view of current public opinion could well






























TABLE I3 Effect of Current Information on Perception of Trends*

In which direction do you think public opinion will move in the future? No More

Easier change difficult (N)

Told public opinion permissive 68-3 I7-0 I4.7 (259) Told public opinion restrictive 47-6 28.6 23.8 (252)

* Row percentages; taub = 0-19; p = 00ooo; missing observations = I9.

compensate for this error by altering their perception of future trends. However, the experimental influence did not follow through; we obtained null results even when we controlled for respondent's perception of trends.

Although we found that the experimental information produced an effect on the interfering variable, we cannot treat this as evidence that it might have had more impact on the dependent variable if it had followed on directly. The only way to test that would be to replicate the results omitting entirely the question about trends in public opinion.

5. SUMMARY

The findings indicate that one powerful influence on an individual's attitude to the law on abortion is the perception he or she has of the dynamic of public opinion in this arena; people who are told that the trend is in a permissive direction are much more likely to endorse permissive views. The effect is particularly marked for those who voice strong views on abortion, and for those who suspect that the trend is away from their own point of view. Information about static current opinion had no effect.

6. DISCUSSION

The discussion of these findings will be split into two parts. First, the meaning of the results internally in the experiment will be considered, and then their

generalizability and significance externally will be assessed.

6. i Internal Validity and Interpretation

As with all experiments, we must consider the possibility that the result is simply artefactual. Orne has shown that respondents pick up cues from experimenters about what is being demanded, and try to 'help' them by giving what they think is the desired response.35 Rosenthal has shown that experimenters' expectations can even be communicated sub rosa to respondents.36

35 M. T. Orne, 'On the Social Psychology of the Psychological Experiment', American

Psychologist, xvi (1962), 776-83. 36 R. Rosenthal, Experimenter Effects in Behavioural Research (New York: Appleton-

Century-Croft, I966).








5. SUMMARY


6. DISCUSSION















5. SUMMARY


6. DISCUSSION











There are several reasons why such artefacts are implausible in our case. First, the respondents did not know until the debriefing at the end of the interview that they had taken part in an experiment. More importantly, most previous experiments on this topic have suffered from what is the reverse of this problem, namely being insufficiently sensitive to detect any effects at all.37 This is actually a very common problem with laboratory experiments.38 Our findings replicate the null findings on the static information, but the trend information produced strong effects. It is unlikely that demand characteristics and expectancy effects operate only on trends, and then in such a selective and structured way that they produce the patterns in Tables 7 and Io.

Treating the effect as real, we must ask how it is produced in this experiment. In the literature on conformity effects in group psychology39 two interpretations prevail: conformity results from either a 'normative effect', where individuals desire directly the rewards which accrue from upholding consensual views (or fear the sanctions which come from deviating from them), or from an 'informational effect', where individuals use the information about majority views as new evidence about reality, and then re-evaluate this new perception of reality. The distinction will be especially important when we consider if we can generalize from abortion attitudes to other areas such as voting; the debate about publishing polls during elections turns rather crucially on whether the public is normatively persuaded towards a candidate by a poll, or merely processes the information contained in the poll in order to cast a more effective vote.

It is attractive to interpret the results of conformity studies as informational effects; this cast human beings in a much pleasanter, more rational light. It is hard, however, to interpret our results in this way. The experimental information about trends in public opinion on abortion could not have given any respondent data of strategic relevance; to make the argument stick, it would be necessary to believe that the information about trends actually altered individuals' perception of the law, which is unlikely. No new arguments, new information about the law or about the issue of abortion were given to anybody, and yet a significant number of people were influenced in their response by the trend information. The most plausible explanation is that the effect is normative.

If the result stems from an irrational desire to conform to perceived norms, why do we only find the effect when we manipulate the information about trends, and why does it affect some groups of people and not others?

37 L. Festinger, 'Laboratory Experiments', in L. Festinger and D. Katz, eds, Research Methods in the Behavioural Sciences (New York: Holt, Rinehart and Winston, 1965).

38 An example of this can be found in the main part of this same investigation. The main purpose of the rest of the survey was to test hypotheses about the effects of information about sentencing on attitudes to crime; despite varying the sentencing information quite markedly in different conditions (telling one group a criminal got a six-month prison sentence and another that he got probation), no significant differences were produced.

39 E.g. C. Fraser, 'Group Risk-taking and Group Polarisation', European Journal of Social Psychology, I (1971), 493-551.


















The failure of information about static public opinion to produce an effect has been viewed with surprise by some earlier researchers,40 since it seems to deny the results of a wide range of conformity experiments in social psychology. These experiments were mostly conducted on small groups, with pressure being exerted by people who were normatively important for the individual. One explanation that has been mounted for the non-effect of opinion polls has been that the views of the general public are normatively irrelevant for individuals. The findings about the effect of trend information show this dismissal to be too hasty.

Insight can be gained from the results of more recent research into attitude changes in small groups. The heavy emphasis on conformity in the early experiments seemed to be contradicted by a series of studies in the I96os which showed that people tended to reach more extreme decisions in groups than they did as individuals. This was originally understood as a move towards risk-taking in groups (the 'risky-shift' phenomenon), but more recent research has shown that this is only true in situations where risk is positively valued (e.g. in business); the general phenomenon seems to involve a shift towards an extreme on a valued dimension (which could in some cases be the dimension of caution).

Most important of all for interpreting our results, some recent work in France suggests that the process of attitude change is crucially mediated by the perceptions that individuals have of the direction of change of that valued dimension, of the changing norms and values in society.41 Paicheler, believing that society's norms are becoming more pro-feminist, shows that deviant but 'norm-oriented' views (in this case extreme pro-feminist) are more resistant to attitude change than deviant and 'anti-norm-oriented' ones (i.e. extreme anti-feminist ones).

Our findings about the powerful effect of trend information on those who believe their own views to be contrary to the trend, i.e. 'anti-norm-oriented', suggest that this is a phenomenon which is not restricted to small group interaction. Furthermore, they suggest a refinement of Paicheler's hypothesis: different individuals have different views about which pole is the 'norm-oriented' one, and this perception is an important key to understand- ing their susceptibility to attitude change.

6.2 External Validity and Interpretation

We must next ask whether this phenomenon occurs in everyday life, and, if so, how powerful it is, and how widespread. No reliance can be placed on the absolute magnitude of the effect discovered in this experiment for two reasons. The first (technical) reason, is that the percentage differences depend not just on the marginal distribution of abortion attitudes, but also on

40 E.g. J. L. Tyson and S. A. Kaplowitz, 'Attitudinal Conformity and Anonymity'. 41 G. Paicheler, 'Norms and Attitude Change I: Polarisation and Styles of Behaviour',

European Journal of Social Psychology, vl (1976), 405-28.




















the marginal distribution of perception, which was artificially manipulated. The second is a general reason which explains why experimental investigations into the effect of information on attitude change tend to produce stronger results than non-experimental investigations into the same phenomenon;42 in an experiment you can focus people's attention on information in a way that may not occur naturally.

To say that the real magnitude of the effect is unknown is not to render the research valueless, of course. The counter to the criticism is to argue that even small effects, if they accumulate, can amount to very powerful forces when taken in aggregate; Beniger's glacier analogy springs to mind. It is not necessary to believe that the very strong effects produced in this experiment occur naturally to argue that we are dealing with a process of real significance.

It is sometimes argued that bandwagon effects cannot really exist, since all opinions would converge to unanimity over time, charismatic leaders would constantly emerge, and countries would become effectively one-party states. There is a grain of truth in this argument in that pure systems of positive feedback are very unstable and very rare in the natural or social world. But that does not stop us concluding that there is a bandwagon element in the

process of opinion formation. Clearly there are a multitude of influences

helping to form opinions on abortion; this experiment suggests that a bandwagon effect is one of them.

In order for this finding to have significance in the external, 'real' world, people must pay attention to opinion polls in the first place. While it was shown in Secion 3 that people do claim to be aware of polls, they probably misperceived the trend in abortion attitudes, suggesting that they are not very acute poll-watchers of social attitudes of this kind. It would be wise, therefore, to temper our conclusion that polls could be having an effect in themselves with this rider: when people pay close attention to them.

There are occasions, of course, especially during elections and by-elections, when people do pay close attention to the polls. Moreover, the press frequently lay stress on changes in opinion when they report polls.43 It is interesting in conclusion to speculate about the possibility that reporting trends in political opinion polls might similarly exert an influence on people before elections. The fear that polls have an effect on the outcome of elections is widespread throughout the world, and has led to various efforts to control polling activity in pre-election periods. In some countries, like

42 C. I. Hovland, 'Reconciling Conflicting Results Derived from Experimental and Survey Results of Attitude Change', in N. Warren and M. Jahoda, eds, Attitudes (Harmondsworth: Penguin, 1966).

43 The error associated with change in party support is, moreover, much greater than that associated with a single estimate (A. Stuart, 'Public Opinion Polls', Journal of the Royal Statistical Society, A, CXLII (1979), 443-67). It is ironic that the most unreliable poll results are not

only the most likely to be picked up by the press (Ivor Crewe, 'Improving but Could Do Better: A Report on the Media and the Polls in the 1979 General Election', in M. Harrop and R. Worcester, eds, Political Communication and the General Election of I979 (London: Macmillan, 1981)) but they are possibly the most influential.
























Germany, the polling companies themselves impose a voluntary embargo on conducting surveys; in others, like Brazil, the publication of results is banned. The idea of imposing similar restrictions in Britain is debated from time to time but has up to now met with hostility, not surprisingly from the polling companies, but also from the House of Commons and from the general public.

The issue was raised with more force recently following the Bermondsey by-election of I982 in which few people deny that the published polls played a

large part in the remarkable movement of support in the eight days before the election from the Labour candidate to the Liberal candidate. Douglas Hoyle, MP, sponsored a Ten Minute Bill, which was once more unsuccessful, to ban

polling in any pre-election period. Interestingly, the debate hinged centrally on whether any effect that polls

might have was normative or informational. Hoyle and his supporters argued that poll results have a normative effect, placing pressure on people directly. The pundits (e.g. The Times, 23 February I983), while agreeing that

bandwagon effects occurred, viewed them as having an informational effect, allowing people to revise their view of majority opinion and so cast their vote more effectively.

The experiment reported here was about an attitude to abortion. The effect

may not generalize to other attitudes, let alone to behaviour such as voting. However, these findings do provide one clear instance of polls having a

powerful normative effect. They must raise the possibility that trend data on candidate support in elections operates in a similar manner, and place that

hypothesis on the research agenda.























back on the bandwagon: the effect of opinion polls on public opinion

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