日心第70回大会（2006）
Reproduction of the Asch experiment without using
confederates
○Kazuo Mori & Miho Arai
(Shinshu University)
Key words: the Asch experiment, conformity, the MORI Technique
Asch (1956) showed that a minority of one tended to conform to
a unanimous majority even when the majority seemed to have
made a wrong choice in a simple visual discrimination task. In the
Asch experiments, the majority comprised confederates and only
the minority participants were naïve.
Mori (2003) invented an innovative presentation method, the
MORI Technique, by means of which an experimenter can present
two different movies simultaneously to two groups of viewers
without their noticing the duality. Mori & Uchida (2006) further
developed it into a more easily used format requiring only one
video projector instead of two. They named it the “fMORI
Technique,” because it utilizes a “fraction” of the light beam of
LCD projector. (See Figure 1.)
In this paper, the Asch experiment was replicated using the
fMORI Technique instead of using confederates.
Methods
Participants: Four same-sex groups of four, one male group
and three female, participated. The grouping was done by the
experimenters from the participant pool. Their answering order
was randomly assigned at the beginning of the session.
S
T
Figure 1 The principle of projecting two different images
with only one projector: fMORI Technique
An LCD projector houses three LCD panels for the three primary colors,
red, green, and blue. Only the LCD panel for green is perpendicular to the
other two in terms of polarization. Therefore, a green component and a
mixture of red and blue (magenta) can be separated with two pairs of
polarizing sunglasses suitable for either of the two color components.
Figure 2 An example of Standard and Comparisons
The greenish part on the top of Standard, as shown in a dotted circle, can
or cannot be seen depending on the type of polarizing sunglasses worn
by the participants. The background is colored appropriately to maximize
the separation of the two images. Random dot noises are added for the
same purpose.
Stimuli: The nine stimulus sets used in Asch (1956) were
reproduced in approximately the same size when projected on the
screen using digital picture editing software (Adobe Photoshop).
The top parts of the Standard lines were drawn in either green or
magenta so that two groups of participants could see them
differently to form a majority and a minority utilizing the fMORI
Technique. (See Figure 2.)
Apparatus: Stimuli were presented on PowerPoint slides with a
personal computer (Apple iBook) and projected by an LCD
projector (EPSON ELP-730) onto a rear screen.
Rear screen: A rear screen was made from an office partition
183cm in height and 146cm in width by changing the window
glass pane from a patterned one to plain ground glass (80cm x
142cm).
Layout of the apparatus: The rear screen was set about 2m
away from the projector. Four chairs were placed in line side by
side about 2m apart on the other side of the screen.
Polarizing sunglasses: Participants were told to wear a pair of
polarizing sunglasses to protect their eyes from glare. The
sunglasses were the same ones as were used in Mori & Uchida
(2006). Three pairs were used to form the majority and one pair
was used for the minority. The sunglasses were put on the chairs
before the participants entered the laboratory. The minority
participants’ sunglasses were placed on the third chair.
Results
No participants noticed the duality. The Asch experiment was
successfully reproduced without using confederates.
Since the experiment has been just started, having been
conducted with only four groups, it is not possible to conduct any
statistical analysis. However, it has been found that one female
participant in the minority showed conformity responses, and
another female responded in the direction of the majority. Asch
(1956) reported that the percentage of conformity was about 30%
in his experiments. Therefore, it can be concluded that the present
experiment reproduced successfully the Asch results themselves.
References
Asch, S. E. (1956). Studies of Independence and Conformity: I. A
Minority of One Against a Unanimous Majority.
Psychological Monograph: General and Applied, 70(9),
Whole No. 416.
Mori, K. (2003). Surreptitiously projecting different movies to two
subsets of viewers. Behavior Research Methods, Instruments,
and Computers, 35, 599-604.
Mori, K. & Uchida, A. (2006). Can Artificially Contrived Success
Affect Subsequent Achievement among Junior High School
Students? Manuscript submitted for publication.
(MORI Kazuo, ARAI Miho)