Here is a child of nine years of age, who has been selected for a class for defectives because he cannot follow the usual lessons in the elementary school. You, however, doctor, put to him some of your usual questions. You ask the child his name, his age, the occupation and address of his parents; the date, day, month, year; some details about his life; you even ask him to read or count. The replies are given to you quietly and correctly. Are you going to refuse to admit him to the special school, and by what right? You have the notes of one, of two, or of three teachers. He cannot follow; he is still with children of seven years of age, in spite of having been at school for three years. It is evident that he is not an idiot, nor an imbecile, nor even feeble-minded to any great extent. But you have been notified that he is behind other children of his age. There is therefore something peculiar about him. It is not a medical question whether he ought to remain in the ordinary school. The doctor cannot go against the opinions which have been given to him, in order to verify whether the retardation is genuine. To do so, it would be necessary for him to make a comparison with the normal condition. Now this varies according to age. The doctor does not know exactly, to two or three years, the normal condition of the mental faculties; nor, after such and such a period of school attendance, the habitual level of instruction reached. That, however, in such special conditions, is the very problem which faces him. We do not hesitate to express the opinion that, in such circumstances, the doctor would be incapable of estimating the intellectual level of the child. He has no more experience in this matter than any other person. Let a doctor seek to pick out a feeble-minded child from a number of normal ones, and he will find how little he is prepared to make the selection.

Physical Examination of Defectives.—But it may be asked: "Is not mental debility associated with physical signs which the doctor alone is able to appreciate?" About this question three kinds of facts may be considered: those pertaining to anthropometry, the stigmata of degeneration, and physiognomy. Let us consider in order what help may be derived from these.

Height and Head Measurements.—Numerous papers have been published upon height and cephalometry. The object of some has been to compare the less intelligent school children with those who are better endowed. Other authors have taken as their subject the study of asylum or hospital cases. The absence or paucity of results of the earlier studies seems to be due to a cause which we have referred to elsewhere (p. 39). The mistake has been made of judging the intelligence of the children by sole reference to the opinion of the teachers, although account should have been taken of the relationship between the age and the stage of instruction. The comparison between the height and head measurements of the hospital cases and those of school children is not subject to the same risk of error, and striking differences between the two have been noticed. But there is yet another factor which must be taken into account if the figures so obtained are to yield all they are capable of teaching. If one confines oneself to comparing the averages of the two sets of children, one finds them almost identical. We have shown that the only suitable method to use here is the method of arranging the figures in series. This proceeding has suggested to one of us a better method still, that of "frontiers." There is for each age a height limit below which the defectives become clearly more numerous. There are limits in the head diameters, upon each side of which are grouped the abnormally small and the hypertrophied heads, which are frequently associated with mental deficiency. We give here the table which one of us has published of the provisional frontiers for height and for the two cephalic diameters.

The Frontiers of Abnormality (Boys).

Age.Height.Antero-Posterior Diameter.Transverse Diameter.Sum of Diameters.
Centimetres.Millimetres.Millimetres.Millimetres.
6100 164134 298
7105 166135
8110 169136 305
9111 171137
10120 172138 310
11124 173139
12130 174140 314
13135 176141
14140 178142 320
15142.5179143.5
16154 180145 325
17147.5181146
18150 182147 329

What this table means is this: If we measure 100 children in an elementary school, we find only a small number (at most 10 per cent.) whose measurements are less than those indicated; if, on the other hand, we measure idiots and imbeciles, the proportion of those whose measurements are inferior is greater, amounting to over 25 per cent. Amongst 120 abnormal children we found not a single one who was below these frontiers in two measurements, whilst 10 per cent. of defectives were below. Certain measurements, therefore, are distinctly suggestive, although, no doubt, not absolutely diagnostic without reference to the subject examined.

The Stigmata of Degeneration.—Everyone has heard of the physical malformations which are called the stigmata of degeneration. Some of these are very apparent, such as a sixth finger on the hand, or a hare-lip, or those deformities of the head, which are called plagiocephalus (obliquely oval cranium), scaphocephalus (boat-shaped cranium), etc. Other stigmata are less apparent, such as abnormal shapes of the ear, irregular growth of hair, of the teeth, alterations in the eye, etc. Some doctors, not all, have made a study of these various stigmata. But school directors and teachers know nothing about them except what the present-day widespread popularisation of medical knowledge has permitted them to know. Evidently it is no part of their business to take up the study, although no State diploma will prevent their doing so if it is their good pleasure. There is no law against it. But they would expose themselves to grave risks of erroneous interpretations owing to their ignorance of the manner in which stigmata are produced, and the ignorance of doctors on this subject is still great. The determination of the stigmata, their enumeration, and their description, belong, therefore, at any rate by preference, to the doctor. God save us from wanting to dispossess him!

But what help could their study render us in the question whether a particular child ought or ought not to be admitted into a class for defectives? There is an opinion which is very widespread, especially amongst teachers and ordinary people, a souvenir of the doctrines of Gall, that the physical stigmata are signs of the original character, and that the possessor of a certain shape of head is certainly defective. "I have taken my son," a worthy mother said to us, "to consult Dr. P., because he was learning nothing in his class. He was sent away from every school I sent him to, and he is unbearable at home. The doctor felt all over his head. He evidently saw that there was something particular wrong with the boy." We do not smile at this good mother. Plenty of other intelligent people hold her opinions, if they are not so naïve in their language. They expect that the moment defective children are brought before them, they will find something peculiar, something ugly, in their physiognomy. And there are plenty of doctors, let us say frankly, who are equally naïve, and, more serious still, allow themselves to be influenced by unconscious suggestions. If, like our worthy mother, we present to the doctor a child as defective, the doctor will, as a general rule, have no difficulty in demonstrating that he must be so. How many of us are there without stigmata? None of us is built upon the model of the ideal man. It is always possible to discover some anatomical detail which will give support to a preconceived opinion. But the same doctor who, on seeing a defective child with adherent ear lobes, will say that that was just what he expected, will abruptly change his opinion if he discovers a whorl of frontal hair on a child who is presented to him as normal, and will refuse to attach to the fact any importance whatever. As a matter of fact, these questions have not yet been studied as they ought to be, by a comparison without parti pris between normal and abnormal children of the same age and in the same environment, and we do not yet know how stigmata should be interpreted. We can only suggest some provisional conclusions.

The first of these conclusions is that the presence or absence of a definite stigma has no exact significance for the individual who bears it; for on the one hand one meets with all kinds of malformations in average normal children, and on the other hand, some who are definitely abnormal are quite normal in their conformation. The stigma, therefore, has not the value of a definitely pathognomonic sign like the crepitating râle of pneumonia, or the transient unconsciousness of epilepsy; but if we compare a group of normal children with a group of abnormal, the total number of the stigmata will be much greater in the second group; and, moreover, the multiplicity of stigmata in a single individual constitutes a strong probability that that individual is abnormal. Here are some facts which support these two propositions:

Recently we made a rapid examination of the heads of fifty-eight school children, and noticed that eighteen of them had some stigma, especially an abnormal shape of the ear. We therefore find stigmata amongst children at the average school level. But of these fifty-eight school children only one had four abnormalities—malformed ears, strabismus, prognathism, and slight scaphocephaly. The others had a maximum of two. The first child alone is certainly defective.