從眾效應

在英文片語中「jump on the bandwagon」意思就是跳上樂隊花車，也就是加入 正在遊行的主流花車當中，代表著進入主流。在這裡有一個意思是，跟隨者選擇 採用他人的意見，自己不假思索其內涵的投入流行當中。在中文裡我們常用「一 窩蜂的現象」來表示這樣的狀況、行為。也因此我們可以其稱為Bandwagon effect，

直接翻譯的意思是樂隊花車效應，社會心理學家們也稱為「從眾效應(conformity effect)」。

「從眾效應」其定義是－人類經常會有一種傾向，去從事或相信其他多數人 城史瓦摩爾學院的社會心理學家所羅門．艾許（Solomon Asch，米爾格蘭的老師）

在1952年做了一個有關人類知覺的實驗，來觀察這個值得注意的現象[維基百科]。

到了2005年，亞特蘭大艾默里大學的神經科學家伯恩斯博士(Dr. Gregory Berns)的團隊加入了核磁共振攝影(MRI)的技術來重做艾許的實驗，利用核磁共振 cerning various matters; some time later they were again asked to state their choices, but now they were also in- formed of the opinions held by authori- ties or large groups of their peers on the same matters. (Often the alleged con- sensus was fictitious.) Most of these studies had substantially the same result:

confronted with opinions contrary to their own, many subjects apparently shifted their judgments in the direction of the views of the majorities or the ex- perts. The late psychologist Edward L.

Thorndike reported that he had suc- ceeded in modifying the esthetic prefer- ences of adu!ts by this procedure. Other psychologists reported that people’s evaluations of the merit of a literary passage could be raised or lowered by ascribing the passage to different au- thors. -4pparently the sheer weight of numbers or authority sufficed to change opinions, even when no arguments for the opinions themselves were provided.

Now the very ease of success in these experiments arouses suspicion. Did the subjects actually change their opinions, or were the experimental victories scored onlv on paper? On grounds of common sense, one must question whether opinions are generally as watery as these studies indicate. There is some reason to wonder whether it was not the investiga- tors who, in their enthusiasm for a theory, were suggestibie. and whether the ostensibly gullible subjects were nok providing answers which they thought good subjects were expected to give.

The investigations were guided by cer- tain underlying assumptions, which to- day are common currency and account for much that is thought and said about the operations of propaganda and public opinion. The assumptions are that peo- ple submit uncritically and painlessly to external manipulation by suggestion or prestige, and that any given idea or value can be “sold” or “unsold” without refer- ence to its merits. W e should be skepti- cal, however, of the supposition that the power of social pressure ne ssarily im- pendence and the capacity to rise above group passim are also open to human beings. Further, one may question on psychological grounds whether it is pos- sible as a ruls to change a person’s judg- ment of a situation or an object without first changing his knowledge or assump- tions about it.

plies uncritical submission

f

effects of group pressure which was car- ried out recently with the help of a num- ber of my associates. The tests not only demonstrate the operations of group pressure upon individuals but also illus- trate a new kind of attack on the prob- lem and some of the more subtle ques- tions that it raises.

A group of seven to nine young men, all college students, are assembled in a classroom for a “psychological experi- ment” in visual judgment. The experi- menter informs them that they will be comparing the lengths of lines. He shows two large white cards. On one is a single vertical black line-the standard whose length is to be matched. On the other two are substantially different, the differ- ence ranging from three quarters of an inch to an inch and three quarters.

The experiment opens uneventfully.

The subjects announce their answers in the order in which they have been seated in the room, and on the first round every person chooses the same matching line.

Then a second set of cards is exposed;

again the group is unanimous. The mem- bers appear read:; to endure politely an- other boring experiment. On the third trial there is an unexpected disturbance.

One person near the end of the grouF disagrees with all the others in his selec- tion of the matching line. He looks sur- prised. indeed incredulous, about the disagreement. On the following trial he disagrees again, while the others remain unanimous in their choice. The dissenter becomes more and more worried and hesitant as the disagreement continues in succeeding trials; he moy pause before announcing his answer and speak in a low voice, or he may smile in an em-

that all the other members of the group were instructed by the experimenter beforehand to give incorrect answers in unanimity at certain points. The single individual who is not a party to this pre- arrangement is the focal subject of our experiment. He is placed in a position in which, while he is actually giving the publicly.

The instructed majority occasionally reports correctly in order to reduce the possibility that the naive subject will sus- pect collusion against him. ( I n only a few cases did the subject actually show suspicion: when this happened, the ex- periment \vas stopped and the results were not counted.) There are 18 trials in each series. and on 12 of these the majority responds erroneously.

How do people respond to group pres- sure in this situation? I shall report first the statistical results of a series in which

ii total of 123 subjects from three institu- tjons of higher learnins (not including my w ~ m . Swarthmore College! were placed in the minority situation de- scribed :hove.

Two alternatives nere open to the subject: he could x t independently, re- pudiating the majority, or he could go along with the majority, repudiating the evidence of his senses. Of the 123 put to the test, a considerable percentage yielded to the majority. Whereas in ordi- nary circumstances individuals matching the lines will make mistakes less than 1 per cent of the time. under group pres-

SUBJECTS WERE SHOWN two rards. One bore a standard line. The other bore three lines, one of which was the same length as the standard. The subjects were asked to choose thisline.

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圖2.4 伯恩斯團隊的從眾實驗

所使用的題目，及受測人員與演員回答順序的安排 圖片來源：Biol Psychiatry 2005

圖2.5 伯恩斯團隊的從眾實驗 受測者的腦部MRI掃描畫面 圖片來源：Biol Psychiatry 2005