ASSOCIATION IN NORMAL SUBJECTS.
Among the most striking and commonly observed manifestations of
insanity are certain disorders of the flow of utterance which appear
to be dependent upon a derangement of the psychical processes commonly
termed association of ideas. These disorders have to some extent been
made the subject of psychological experimentation, and the object of
this investigation is to continue and extend the study of these
phenomena by an application of the experimental method known as the
association test.
§ 1. METHOD OF INVESTIGATION.
In this investigation we have followed a modified form of the method
developed by Sommer,[1] the essential feature of which is the
statistical treatment of results obtained by uniform technique from a
large number of cases.
[Footnote 1: Diagnostik der Geisteskrankheiten, p. 112.]
The stimulus consists of a series of one hundred spoken words, to each
of which the subject is directed to react by the first word which it
makes him think of. In the selection of the stimulus words, sixty-six
of which were taken from the list suggested by Sommer, we have taken
care to avoid such words as are especially liable to call up personal
experiences, and have so arranged the words as to separate any two
which bear an obviously close relation to one another. After much
preliminary experimentation we adopted the following list of words:
01 Table
02 Dark
03 Music
04 Sickness
05 Man
06 Deep
07 Soft
08 Eating
09 Mountain
10 House
11 Black
12 Mutton
13 Comfort
14 Hand
15 Short
16 Fruit
17 Butterfly
18 Smooth
19 Command
20 Chair
21 Sweet
22 Whistle
23 Woman
24 Cold
25 Slow
26 Wish
27 River
28 White
29 Beautiful
30 Window
31 Rough
32 Citizen
33 Foot
34 Spider
35 Needle
36 Red
37 Sleep
38 Anger
39 Carpet
40 Girl
41 High
42 Working
43 Sour
44 Earth
45 Trouble
46 Soldier
47 Cabbage
48 Hard
49 Eagle
50 Stomach
No attempt is made to secure uniformity of external conditions for the
test; the aim has been rather to make it so simple as to render
strictly experimental conditions unnecessary. The test may be made in
any room that is reasonably free from distracting influences; the
subject is seated with his back toward the experimenter, so that he
cannot see the record; he is requested to respond to each stimulus
word by one word, the first word that occurs to him other than the
stimulus word itself, and on no account more than one word. If an
untrained subject reacts by a sentence or phrase, a compound word, or
a different grammatical form of the stimulus word, the reaction is
left unrecorded, and the stimulus word is repeated at the close of the
test.
In this investigation no account is taken of the reaction time. The
reasons for this will be explained later.
The general plan has been first to apply the test to normal persons,
so as to derive empirically a normal standard and to determine, if
possible, the nature and limits of normal variation; and then to apply
it to cases of various forms of insanity and to compare the results
with the normal standard, with a view to determining the nature of
pathological variation.
§ 2. THE NORMAL STANDARD.
In order to establish a standard which should fairly represent at
least all the common types of association and which should show the
extent of such variation as might be due to differences in sex,
temperament, education, and environment, we have applied the test to
over one thousand normal subjects.
Among these subjects were persons of both sexes and of ages ranging
from eight years to over eighty years, persons following different
occupations, possessing various degrees of mental capacity and
education, and living in widely separated localities. Many were from
Ireland, and some of these had but recently arrived in this country;
others were from different parts of Europe, but all were able to speak
English with at least fair fluency. Over two hundred of the subjects,
including a few university professors and other highly practiced
observers, were professional men and women or college students. About
five hundred were employed in one or another of the New York State
hospitals for the insane, either as nurses and attendants or as
workers at various trades; the majority of these were persons of
common school education, but the group includes also, on the one hand,
a considerable number of high school graduates; and on the other hand,
a few laborers who were almost or wholly illiterate. Nearly one
hundred and fifty of the subjects were boys and girls of high school
age, pupils of the Ethical Culture School, New York City. The
remaining subjects form a miscellaneous group, consisting largely of
clerks and farmers.
§ 3. THE FREQUENCY TABLES.
From the records obtained from these normal subjects, including in all
100,000 reactions, we have compiled a series of tables, one for each
stimulus word, showing all the different reactions given by one
thousand subjects in response to that stimulus word, and the frequency
with which each reaction has occurred. [1] These tables will be found
at the end of this paper.
[Footnote 1: A similar method of treating associations has been used
by Cattell (Mind, Vol. XII, p. 68; Vol. XIV, p. 230), and more
recently by Reinhold (Zeitschr. f. Psychol., Vol. LIV, p. 183), but
for other purposes.]
With the exception of a few distinctive proper names, which are
indicated by initials, we have followed the plan of introducing each
word into the table exactly as it was found in the record. In the
arrangement of the words in each table, we have placed together all
the derivatives of a single root, regardless of the strict
alphabetical order.[1]
[Footnote 1: It should be mentioned that we have discovered a few
errors in these tables. Some of these were made in compiling them from
the records, and were evidently due to the assistant's difficulty of
reading a strange handwriting. Other errors have been found in the
records themselves. Each of the stimulus words _butter_, _tobacco_ and
_king_ appears from the tables to have been repeated by a subject as a
reaction; such a reaction, had it occurred, would not have been
accepted, and it is plain that the experimenter wrote the stimulus
word in the space where the reaction word should have been written.
Still other errors were due to the experimenter's failure to speak
with sufficient distinctness when reading off the stimulus words;
thus, the reaction _barks_ in response to _dark_ indicates that the
stimulus word was probably understood as _dog_; and the reactions
_blue_ and _color_ in response to _bread_ indicate that the stimulus
word was understood as _red_.]
The total number of different words elicited in response to any
stimulus word is limited, varying from two hundred and eighty words in
response to _anger_ to seventy-two words in response to _needle_.
Furthermore, for the great majority of subjects the limits are still
narrower; to take a striking instance, in response to _dark_ eight
hundred subjects gave one or another of the following seven words:
_light, night, black, color, room, bright, gloomy;_ while only two
hundred gave reactions other than these words; and only seventy
subjects, out of the total number of one thousand, gave reactions
which were not given by any other subject.
If any record obtained by this method be examined by referring to the
frequency tables, the reactions contained in it will fall into two
classes: the _common_ reactions, those which are to be found in
the tables, and the _individual_ reactions, those which are not
to be found in the tables. For the sake of accuracy, any reaction word
which is not found in the table in its identical form, but which is a
grammatical variant of a word found there, may be classed as
_doubtful_.
The value of any reaction may be expressed by the figure representing
the percentage of subjects who gave it. Thus the reaction,
_table--chair_, which was given by two hundred and sixty-seven
out of the total of our one thousand subjects, possesses a value of
26.7 per cent. The significance of this value from the clinical
standpoint will be discussed later.
§ 4. NORMAL ASSOCIATIONAL TENDENCIES
The normal subjects gave, on the average. 6.8 per cent of individual
reactions, 1.5 per cent of doubtful ones, and 91.7 cent of common
ones. The range of variation was rather wide, a considerable number of
subjects giving no individual reactions at all, while a few gave over
30 per cent.[1]
[Footnote 1: In the study of the reactions furnished by our normal
subjects it was possible to analyze the record of any subject only by
removing it from the mass of material which forms our tables, and
using as the standard of comparison the reactions of the remaining 999
subjects.]
In order to determine the influence of age, sex, and education upon
the tendency to give reactions of various values, we have selected
three groups of subjects for special study: (1) one hundred persons of
collegiate or professional education; (2) one hundred persons of
common school education, employed in one of the State hospitals as
attendants, but not as trained nurses; and (3) seventy-eight children
under sixteen years of age. The reactions given by these subjects have
been classified according to frequency of occurrence into seven
groups: (a) individual reactions (value 0); (b) doubtful reactions
(value ±); (c) reactions given by one other person (value 0.1 per
cent); (d) those given by from two to five others (value 0.2--0.5 per
cent); (e) those given by from six to fifteen others (value 0.6-1.5
per cent); (f) those given by from sixteen to one hundred others
(value 1.6--10.0 per cent); and (g) those given by more than one
hundred others (value over 10.0 per cent). The averages obtained from
these groups of subjects are shown in Table 1, and the figures for men
and women are given separately.
TABLE I
Value of reaction 0 ± 0.1 0.2-0.5 0.6-1.5 1.6-10 >10
Sex Number % % % % % % %
of cases
Persons of M.. 60 9.2 1.8 5.2 9.7 11.0 27.8 85.5
collegiate F... 40 9.5 1.8 8.0 9.8 11.7 28.0 83.4
education Both 100 9.3 1.8 4.7 8.7 11.8 28.2 34.4
Persons of M.. 50 5.8 1.6 8.6 8.3 10.2 81.6 88.7
common school F.. 50 4.6 1.8 8.8 7.1 9.4 82.0 42.1
education Both 100 5.2 1.4 3.5 7.7 9.8 81.8 40.4
School children M... 33 5.9 0.8 4.2 8.7 10.0 28.6 88.5
under 16 Jr. F.. 45 5.0 1.0 4.6 9.8 11.0 80.1 36.7
years of age Both 78 5.7 1.4 4.6 9.8 11.2 29.4 87.4
General average. Both.1000 6.8 1.5
It will be observed that the proportion of individual reactions given
by the subjects of collegiate education is slightly above the general
average for all subjects, while that of each of the other classes is
below the general average. In view, however, of the wide limits of
variation, among the thousand subjects, these deviations from the
general average are no larger than might quite possibly occur by
chance, and the number of cases in each group is so small that the
conclusion that education tends to increase the number of individual
reactions would hardly be justified.
It will be observed also that this comparative study does not show any
considerable differences corresponding to age or sex.
With regard to the type of reaction, it is possible to select groups
of records which present more or less consistently one of the
following special tendencies: (1) the tendency to react by contrasts;
(2) the tendency to react by synonyms or other defining terms; and (3)
the tendency to react by qualifying or specifying terms. How clearly
the selected groups show these tendencies is indicated by Table
II. The majority of records, however, present no such tendency in a
consistent way; nor is there any evidence to show that these
tendencies, when they occur, are to be regarded as manifestations of
permanent mental characteristics, since they might quite possibly be
due to a more or less accidental and transient associational
direction. No further study has as yet been made of these tendencies,
for the reason that they do not appear to possess any pathological
significance.
TABLE II.
Special group values.
_____________________________________
Stimulus Reaction General Contrasting Defining Specifying
word. word. value. group 49 group 73 group 84
| subjects subjects subjects
|----- % No. % No. % No. %
chair........... 26.7 25 51.0 11 15.1 10 11.9
1. Table....{ furniture....... 7.5 0 0 13 17.8 4 4.8
round........... 1.0 1 2.0 0 0 4 4.5
wood............ 7.6 2 4.1 9 12.3 10 11.9
cotton.......... 2.8 0 0 1 1.4 5 6.0
easy............ 3.4 0 0 8 11.0 1 1.2
feathers........ 2.4 0 0 1 1.4 5 6.0
7. Soft.....{ hard............ 36.5 34 69.4 14 19.2 18 21.4
silk............ 1.0 0 0 0 0 2 2.4
sponge.......... 2.2 0 0 0 0 4 4.8
cloth........... 1.7 1 2.0 0 0 3 3.6
color........... 12.9 0 0 20 27.4 6 7.1
11. Black...{ dress........... 2.9 1 2.0 1 1.4 9 10.7
ink............. 1.4 0 0 1 1.4 4 4.8
white........... 33.9 31 63.3 17 23.3 18 21.4
desire.......... 19.7 7 14.3 21 28.8 10 11.9
26. Wish....{ longing......... 1.9 1 2.0 6 8.2 2 2.4
money........... 3.2 0 0 1 1.4 3 3.6
flowers......... 4.2 0 0 1 1.4 7 8.3
girl............ 2.4 0 0 0 0 5 0.0
29. Beau- homely.......... 2.7 3 6.1 0 0 0 0
tiful..{ lovely.......... 6.4 2 4.1 7 9.6 2 2.4
pleasing........ 1.6 0 0 3 4.1 0 0
sky............. 1.6 0 0 0 0 3 3.6
ugly............ 6.6 13 26.5 3 4.1 0 0
court........... 6.4 2 4.1 5 6.8 10 11.9
56. Justice.{ injustice....... 2.6 6 12.2 1 1.4 0 0
right........... 15.7 3 6.1 20 27.4 13 15.5
comfort......... 2.6 0 0 5 6.8 1 1.2
disease......... 0.9 2 4.1 0 0 1 1.2
59. Health..{ good............ 9.4 2 4.1 8 11.0 18 21.4
sickness........ 15.3 23 46.9 6 8.2 1 1.2
strength........ 11.2 2 4.1 12 16.4 4 4.8
arrow........... 1.3 0 0 0 0 2 2.4
fast............ 22.2 0 0 25 34.2 15 17.9
horse........... 2.8 1 2.0 1 1.4 6 7.1
65. Swift...{ quick........... 11.7 1 2.0 22 30.1 2 2.4
run............. 1.9 0 0 0 0 4 4.8
runner.......... 1.3 0 0 0 0 1 1.2
slow............ 19.0 30 61.2 2 2.7 4 4.8
speed........... 2.9 1 2.0 5 6.8 0 0
disagreeable.... 1.0 0 0 2 2.7 0 0
distasteful..... 1.0 0 0 4 5.5 0 0
gall............ 4.2 0 0 2 2.7 8 9.5
76. Bitter..{ medicine........ 3.7 0 0 0 0 3 3.6
quinine......... 2.3 0 0 0 0 6 7.1
sweet........... 30.5 31 63.3 8 11.0 12 14.3
taste........... 6.6 1 2.0 17 23.3 3 3.6
bread........... 20.6 17 34.7 4 5.5 18 21.4
eatable......... 1.2 0 0 9 12.3 0 0
81. Butter..{ food............ 6.3 1 2.0 14 19.2 3 3.6
sweet........... 1.2 0 0 0 0 3 3.6
yellow.......... 8.0 0 0 0 0 18 21.4
gladness........ 4.4 0 0 7 9.6 1 1.2
grief........... 1.8 4 8.2 0 0 0 0
86. Joy.....{ pleasure........ 12.1 1 2.0 13 17.8 7 8.3
sadness......... 1.3 2 4.1 0 0 0 0
sorrow.......... 13.5 23 46.9 2 2.7 2 2.4
§ 5. PRACTICAL CONSIDERATIONS.
This method is so simple that it requires but little training on the
part of the experimenter, and but little co-operation on the part of
the subject. It is not to be assumed that every reaction obtained by
it is a true and immediate association to the corresponding stimulus
word; but we have found it sufficient for the purpose of the test if
the subject can be induced to give, in response to each stimulus word,
any one word other than the stimulus word itself. No attempt is made
to determine the exact degree of co-operation in any case.
In the early stages of this investigation the reaction time was
regularly recorded. The results showed remarkable variations, among
both normal and insane subjects. In a series of twenty-five tests,
made more recently upon normal subjects, ninety reactions occupied
more than ten seconds, and fifty-four of the stimulus words elicited a
ten-second response from at least one subject.[1]
[Footnote 1: These tests were made by Dr. F. Lyman Wells, of the
McLean Hospital, Waverley, Mass., and he has kindly furnished these
data.]
It is noteworthy that these extremely long intervals occur in
connection with reactions of widely differing values. That they are by
no means limited to individual reactions is shown in Table III. by a
group of selected reactions, all given by normal subjects.
TABLE III.
Word combination Reaction time Value of
in seconds. reaction.
comfort--happiness 20 5.0%
short--long 11 27.9%
smooth--plane 16 2.3%
woman--lady 40 4.1%
hard--iron 12 2.4%
justice--judge 20 9.1%
memory--thought 20 8.1%
joy--pleasure 18 12.1%
It is apparent, even from a superficial examination of the material,
that the factors which cause variations of reaction time, both in the
normal state and in pathological states, are numerous and complex.
It has been the purpose of this study to establish as far as possible
strictly objective criteria for distinguishing normal from abnormal
associations, and for this reason we have made no attempt to determine
by means of introspection the causes of variations of reaction time.
It would seem that the importance and magnitude of the problem of
association time are such as to demand not merely a crude measurement
of the gross reaction time in a large number of cases, but rather a
special investigation by such exact methods as have been used by
Cattell [1] and others in the analysis of the complex reaction. It
would be impracticable for us to employ such methods in a study so
extensive as this.
[Footnote 1: Mind, Vol. XI, 1886.]
In view of these considerations we discontinued the recording of the
reaction time.
If the association test is to be useful in the study of pathological
conditions, it is of great importance to have a reliable measure of
the associational value of a pair of ideas. Many attempts have been
made to modify and amplify the classical grouping of associations
according to similarity, contrast, contiguity, and sequence, so as to
make it serviceable in differentiating between normal and abnormal
associations.
In this study we attempted to apply Aschaffenburg's [1] classification
of reactions, but without success. Our failure to utilize this system
of classification is assigned to the following considerations: (1)
Distinctions between associations according to logical relations are
extremely difficult to define; in many cases there is room for
difference of opinion as to the proper place for an association, and
thus the application of a logical scheme depends largely upon the
personal equation of the observer; that even experienced observers
cannot, in all cases, agree in placing an association is shown by
Aschaffenburg's criticisms of the opinions of other observers on this
point.[2] (2) Logical distinctions do not bring out clearly the
differences between the reactions of normal subjects and those of
insane subjects; logically, the reaction _bath--ink_, which was given
by a patient, might be placed in the class with the reaction
_bath--water_, although there is an obvious difference between the two
reactions. (3) Many of the reactions given by insane subjects possess
no obvious logical value whatever; but since any combination of ideas
may represent a relationship, either real or imagined, it would be
arbitrary to characterize such a reaction as incoherent.
[Footnote 1: Experimentelle Studien uber Association. Psychologische
Arbeiten, Vol. I, p. 209; Vol. II, p. 1; Vol. IV, p. 235.]
[Footnote 2: Loc. cit, Vol. 1, pp. 226-227.]
The criterion of values which is used in this study is an empirical
one. As has already been explained (p. 8), every word contained in the
frequency tables possesses a value of at least 0.1 per cent, and other
words have a zero value. With the aid of our method the difficulty of
classifying the reactions quoted above is obviated, as it is necessary
only to refer to the table to find their proper values: the value of
the reaction _bath--water_ is 33.9 per cent, while that of the
reaction _bath--ink_ is 0.
Logically the combination _health--wealth_ may be placed in any
one of four classes, as follows:
/ intrinsic / causal dependence
health--wealth / \ coordination
\
\ extrinsic / speech reminiscence
\ sound similarity
But since our table shows this association to have an empirical value
of 7.6 per cent, it becomes immaterial which of its logical relations
is to be considered the strongest. It is mainly important, from our
point of view, to separate reactions possessing an empirical value
from those whose value is zero.
§ 6. AN EMPIRICAL PRINCIPLE OF NORMAL ASSOCIATION.
On a general survey of the whole mass of material which forms the
basis of the first part of this study, we are led to observe that
_the one tendency which appears to be almost universal among normal
persons is the tendency to give in response to any stimulus word one
or another of a small group of common reactions_.
It appears from the pathological material now on hand that this
tendency is greatly weakened in some cases of mental disease. Many
patients have given more than 50 per cent of individual reactions.
It should be mentioned that occasionally a presumably normal subject
has given a record very similar to those obtained from patients, in
respect to both the number and the nature of the individual reactions.
A few subjects who gave peculiar reactions were known to possess
significant eccentricities, and for this reason we excluded their
records from the thousand records which furnished the basis for the
frequency tables; we excluded also a few peculiar records obtained
from subjects of whom nothing was known, on the ground that such
records would serve only to make the tables more cumbersome, without
adding anything to their practical value. The total number of records
thus excluded was seventeen.
It will be apparent to anyone who examines the frequency tables that
the reactions obtained from one thousand persons fall short of
exhausting the normal associational possibilities of these stimulus
words. The tables, however, have been found to be sufficiently
inclusive for the practical purpose which they were intended to
serve. Common reactions, whether given by a sane or an insane subject,
may, in the vast majority of instances, safely be regarded as
normal. As to individual reactions, they cannot all be regarded as
abnormal, but they include nearly all those reactions which are worthy
of special analysis in view of their possible pathological
significance. What can be said further of individual reactions,
whether normal or abnormal, will appear in the second part of this
contribution.