The Incidence of Feeblemindedness Among Cases Examined in the Psychological Clinic of the University of Pennsylvania
- Author:
Miles Murphy
University of Pennsylvania
The records of the Psychological Clinic at the University of Pennsylvania show that 10,168 individuals have been examined in this clinic since it was founded in 1896. Of this numbei 9,043, or 89 per cent, have been examined during the twenty year period from 1912 to 1931 inclusive. The present study is an investigation of the incidence of feeblemindedness among the cases examined during this period.
Certain cases out of this total of more than nine thousand had to be eliminated, however, for reasons to be given. At the present time the work of the Psychological Clinic really comprises three clinics: the general mental clinic, the speech clinic, and the vocational guidance clinic. Cases examined in the vocational guidance clinic are excluded from the present study. This clinic has been in operation only during the last eleven years of the twenty year period during which time 832 individuals have received vocational guidance examinations. Of this number only 1.6 per cent were diagnosed as feebleminded. It seemed therefore that to include the vocational guidance cases would introduce a preponderance of normal individuals during the second half of the period with which we are concerned, and thus make it not strictly comparable with the first. It is obvious that with the beginning of the vocational guidance clinic a different group of persons was attracted to the services of the Psychological Clinic.
It was also necessary to exclude those cases in which a speech diagnosis alone was made with no reference to the mental status of the subject. This exclusion eliminates an additional 1,237 cases. It is to be noted that this figure does not give any indication of the number of cases actually receiving a speech examination. Many of the individuals examined in the speech clinic have been given a mental examination as well, and in those cases the complete diagnosis includes both a diagnosis of the speech condition and also a diagnosis of general mental status. Since the present study is one of general mental diagnoses, the speech cases receiving a mental examination are included. It is highly probable that most of the speech cases in which no reference is made to mental status are of normal mentality, but of this we can not be certain. Finally there were sixteen cases in which the records could not be located. The number of cases remaining for consideration in this investigation is thus reduced to 6,958. The records of these cases were examined in the files of the Psychological Clinic in order to determine the incidence of feeblemindedness.1
Of this group 60 per cent were diagnosed as having normal mentality; 29 per cent were diagnosed as feebleminded; 4 per cent were diagnosed as of borderline mentality; and in 7 per cent of the cases diagnosis was deferred.
A feebleminded person, as considered by examiners in this clinic, is one who because of mental defect, either congenital or appearing early in life, is unable to take his place in society without external supervision or support. The criterion is primarily a social one, and is not based on any absolute test results. The cases in which diagnosis is deferred require an explanation. The most common situation in which diagnosis is deferred is one in which the examiner is unable to reach a conclusion and desires a second examination, an extended period of observation, a period of diagnostic education, a medical examination, a school report or some other additional information. In case this information is secured, diagnosis is subsequently made. The seven per cent of cases indicated as deferred are those in which for some reason or another the recommendation for further study was not carried out, and final diagnosis could not be made.
In many of the cases of feeblemindedness the degree of mental deficiency, that is of imbecility or idiocy, was given. This practice was not, however, sufficiently uniform to render this material suitable for investigation. The type of mental deficiency was also given in those cases in which it could be definitely ascertained. In only one type was this incidence computed?the Mongolian. This type of feeblemindedness is quite definite and also quite easily recognized so that it is noted in the case record. Of the 2,036 feebleminded individuals among those investigated, 154, or 7.5 per cent, were classified as Mongolians.
1 The writer is greatly indebted to Miss Olive Norman and to Miss Mary Kinsey, members of the Clinic staff, for assistance in compiling the results of the study.
We do not intend to imply that the incidence of feeblemindedness in our group throws any light upon the problem of the incidence of this condition in the general population. The estimates in this latter respect vary all the way from about one half of one per cent to five or six per cent. The primary purpose of the present investigation is to show the variation in the incidence of feeblemindedness among clinic cases from year to year. Such a study ought to show the changes, if any, which occur in the clinic population during the twenty year period, and thus indicate to a certain extent the function of the Psychological Clinic in the community. Table I shows the total number of cases examined during each year and also the number and per cent of these cases which were Table I Year Total Cases Normal No. Per cent Feebleminded No. Per cent Borderline No. Per cent Deferred No. Per cent 1912. 1913. 1914. 1915. 1916. 1917. 1918. 1919. 1920. 1921 . 1922. 1923. 1924. 1925. 1926. 1927. 1928. 1929 1930 1931 246 328 334 321 350 365 258 438 413 393 413 327 244 250 289 333 393 400 460 403 63 133 141 133 133 146 134 243 236 215 265 211 167 185 208 239 295 319 377 331 25.6 40.5 42.2 41.4 38.0 40.0 52.0 55.5 57.2 54.7 64.2 64.5 68.4 74.0 71.9 71.8 75.1 79.75 82.0 82.1 105 125 120 129 158 183 100 156 141 137 100 85 56 47 65 74 75 66 66 48 42.7 38.1 35.9 40.2 45.2 50.2 38.7 35.6 34.1 34.8 24.2 26.0 23.0 18.8 22.5 22.2 19.1 16.5 14.3 11.9 13 16 26 22 19 18 11 3 5 16 23 18 11 6 9 6 8 7 12 16 5.3 4.9 7.8 6.9 5.4 4.9 4.3 .7 1.2 4.1 5.6 5.5 4.5 2.4 3.1 1.8 2.0 1.75 2.6 4.0 65 54 47 37 40 18 13 36 31 25 25 13 10 12 7 14 15 8 5 26.4 16.5 14.1 11.5 11.4 4.9 5.0 8.2 7.5 6.4 6.0 4.0 4.1 4.8 2.4 4.2 3.8 2.0 1.1 2.0 6958 4,174 2,036 265 483 normal, feebleminded, borderline, and in which diagnosis was deferred. The incidence of feeblemindedness from year to year is shown graphically in Figure 1.
Examination of the data reveals a general decrease in the incidence of feeblemindedness among clinic cases during the period. There is one outstanding exception?an increase during years 1916, 1917 and 1918, for which it is difficult to account. The highest incidence occurred in 1917 when almost exactly half of the individuals examined were diagnosed as feebleminded. The lowest incidence was reached in 1931 when slightly less than twelve per cent of the cases were diagnosed as feebleminded. During the past five years the decrease has been particularly consistent. It will be noticed that the minimum incidence is still much higher than the highest estimate of the incidence of feeblemindedness in the general population, so that the cases examined in the Psychological Clinic still constitute a highly selected group. The data also indicate a decided decrease in the number of cases in which diagnosis was deferred. This is not to be attributed to increased certainty on the part of examiners, but to other factors. In the first place, with a decrease in the number of feebleminded there is naturally a decrease in the number of cases in which the differential diagnosis as between normality and feeblemindedness requires additional study and information. In the second place there appears to have been increasing effort in the follow up of the first examination, and also an increase in the cooperation of parents and others. To assign reasons for the increasing number of normal children examined in the Psychological Clinic and for the corresponding decrease in the number of feebleminded examined is to deal largely in the realm of conjecture. We need hardly say that there is no | I r?I 1 ? 1 ? I 1 3II 1 1 1 ‘ -1 “1 Fig. 1. Per cent of cases diagnosed feebleminded from 1912 to 1931 * * Fig. 1. Per cent of cases diagnosed feebleminded from 1912 to 1931 reason whatever to believe that the decrease in the incidence of feeblemindedness among cases examined in the Psychological Clinic points to any actual decrease in the number of feebleminded in the general population.
In part the change in the clinic population is due to the presence of other agencies through which feebleminded individuals are discovered. In 1912 at the beginning of the period of our study, although the Psychological Clinic had been in operation for sixteen years, clinical psychology was still very much of a new thing in the world, and the number of organizations which provided clinical services was very small. The problem of feeblemindedness, and the accurate determination of its presence in a given individual constituted one of the most pressing problems in which the aid of the Psychological Clinic might be sought. Today this situation has changed. The public schools of Philadelphia employ a group of psychologists who are daily examining cases of maladjustment in school. Certainly a number of feebleminded children are thus detected very early in their school life. The courts of the city employ psychologists, and the delinquent feebleminded are likely to come to their attention; several hospitals also provide service in clinical psychology in medical cases where a problem of mental abnormality is suspected.
We believe, however, that the chief reason for the decrease in the frequency with which the diagnosis of feeblemindedness is encountered in clinic cases is to be found in the attitude of the public toward psychology in general and toward the psychological clinic in particular. It is not necessary to call attention to the great popularity of psychology?often enough unproductive of honor to the subject. In no branch of psychology is this more true than in relation to the child problem, and the “problem child.” The “problem child” might almost be said to be a child of the last ten years. “With all this dissemination of information about psychology, and particularly child psychology, there has gradually developed a belief that psychology can be of benefit and service to every child and every individual, and deficiency or abnormality of some sort is not a necessary card of admission to the Psychological Clinic. It might be pointed out here that if cases brought to the vocational guidance clinic were included in our study the decrease in the incidence of feeblemindedness would be even more marked than it is now. During the past ten years there has also been a very great increase in the number of definitely superior children brought to the clinic.
When the Psychological Clinic was founded at this University, one of the stimulating situations was the need for the mental analysis of normal children not succeeding in adjustment to school and other demands of life often because of defects difficult to discover, and not because of gross feeblemindedness. Such children now make up the larger proportion of cases examined in the clinic. There was a time after the clinic was organized when it of necessity acted as a social agency in examining children suspected of mental deficiency and in making a differential diagnosis. We further believe that at the present time with the emphasis upon normal, but maladjusted, and incidentally often superior children, it is returning more nearly to the original intention of its foundation.
Summary
From 1912 to 1931, 6,958 individuals received mental examinations in the Psychological Clinic for whom records were available. Of this number 2,036, or 29 per cent, were diagnosed as feebleminded. Of the feebleminded group 154, or 7.5 per cent, were of the Mongolian type. There was during the period in general a decrease in the incidence of feeblemindedness among cases examined. The maximum incidence was 50 per cent in 1917; the minimum, 12 per cent in 1931. The decrease during the past five years has been particularly consistent. The reason for this change is probably to be found largely in a changing orientation on the part of the public toward clinical psychology.
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