On Experimental Psychology and Philosophy
Raiten Taya
Okayama University
In most textbooks of “Introduction to Psychology”, it has been written that
contemporary experimental psychology began in 1879 when Wundt opened hisexperimental laboratory at Leipzig. He was originally a physiologist. According tohim, psychologists studies not the substance of mind, but the immediate experience,or one’s consciousness obtained through introspection. He made only an abortive
attempt to find mental elements to begin psychology as science. But what he wasmost interested in was not the mental element but “apperception”, or aphilosophical concept devised by Kant, which contained an active process notdirectly observable by any experiment. Thus, he described Psychology still as aphilosopher and was not yet an experimentalist.
Experimental Psychology was gradually formed during the period between 1879
and 2000. As soon as Wundt opened his laboratory, a lot of researchers came toWundt from all over the world, including Prof. Matsumoto from Japan. They cameback to their home university a few years later, and opened their own laboratories.
Although they would still not have any clear idea of mental element, perhaps they
accepted these experimental methods to be psychologists of the newest style. They
wanted to create some new fields of sciences, where their specialty could be well
accepted. Philosophers also wanted to make their fields more specific, and actually
got a few new styles of philosophy such as phenomenology and analytic philosophy.
In this era, most researchers wanted to become any specialists. Generally,
specialists began to appear only from this 19 century.
The most influential works in psychology might be achieved by Fechner’s
psychophysics rather than by Wundt’s psychology. Prof. Motora, the first professor
at Tokyo University, began his lecture only 9 years later than the opening ofWundt’s laboratory. He lectured first not on Wundt but on Fechner. He wasoriginallya physicist, and was clearly experimental and scientific.

I have learned Psychology as a student since 1964. Let me show you my firstexperience on Mueller-Lyer Illusion Experiment.
Mueller-Lyer Illusion (1)Figure 1

Our task was set out extremely simple. Just change the length of the upper shafts(see Fig.1) so that these two shafts might match in lengths with each other. The
task is certainly experimental and quantitative.
As these figures are very famous, most of you might already know that the shaft
with outwards arrows appears longer than the shaft with inwards arrows. Most
students shortened the length of the upper shaft. But a few of them extended it. I
asked one of them whether he really perceived that the upper shaft was shorter
than the lower shaft. He answered to me that he had known these figures to causeillusions. He decided not to be deceived, and he decided to extend a little.
Mueller-Lyer Illusion (2)Fig. 2> ―<<―>In the conditions where there are some gaps between shaft and arrows, theillusion appears frequently reversed; i.e., the left shaft in Fig. 2 appears shorter
than the right shaft. This reversed illusion phenomenon has been known rather
recently, for these 30 years.
I found that no one had yet discussed on this problem. Then I measured theamounts of illusion in these two figures, and tried to find a consistent explanationon these results. A journal accepted my paper as a new finding.
Now you may clearly understand that even a young researcher can find a newphenomenon in the field of Experimental psychology. It is enough to find anything
new, even in a very tiny field such as these two Mueller-Lyer illusions.
But frankly speaking, you may not be glad to think that any part of your mind canbe treated experimentally. Please just try to find a tiny part of your mind where you
may allow it to treat experimentally. An example may be found in sensory scales.
The loudness of a tone can be expressed, e.g., as 100 db. We use this unit in our daily
life, as if it might be a physical scale. The subjective impression of loudness of a tone
could never be compared between two individuals. But today, 100 db is used as if it
might be a physical loudness. In the process of constructing such a scale, we could
not help but change the idea of loudness a little, so that we may apply the science
more easily to our sensation concept.
After the World War II, a big era of experimental social psychology began.
There, individual judgments have lost their value as data, and only amean judgment of one group is frequently treated as the first significant data.
Every data becomes significant only after statistic procedures. Here again, thescience changed a little in this field of experimental social psychology.
From this perspective, I will give some comments on experimental philosophy.
(End)