due to more advanced age. The form of the psychograph also changes with age.

Neither professional training and experience nor the characteristics of the tests importantly influence, so far as analysis indicates, the intellectual rating of the medical group.

Method of selection, on the other hand, appears to be responsible to at least as great an extent as is age for the unsatisfactory intelligence of medical officers. Whereas, for most other arms of the service candidates for commission were sent to officers' training schools and there subjected to rigorous training and systematic examinations which tended to eliminate the intellectually incompetent, appointments to the Medical Corps, because of the imperative need for large numbers of medical officers, were made directly on the basis of age, certification by the American Medical Association, experience (and sometimes professional examination), prior to enrollment in the medical officers' training camp. This difference in procedure undoubtedly worked to the disadvantage of the Medical Department, so far as the intelligence of its officers is concerned. In the Medical Corps experience and professional reputation counted heavily. In the other arms of the service military educability and adaptability under the eye of instructors with whom rested the power of recommendation counted most of all.

Given identical age groups and similar methods of military selection, it seems probable that the intellectual status of the Medical Corps would differ little from that of the Engineers or Artillery. The psychographs for these groups might, however, differ extremely, thus indicating either primary differences in intellectual constitution or differences induced by professional training and experience.

3. Education. The typical medical officer is a high school graduate with about four years' professional training. He has devoted more of his life to schooling than has the officer of any other arm of the service. His median length of schooling is 15.8 years, whereas that of the Engineer is 15.3 and of the Quartermaster

12.4.

4. Experience. In general the medical officer is more experienced than any other type of officer. The medical group studied reported 11.07 years of experience. This fact gives point to the statement made above that experience was an important consideration in the appointment of medical as contrasted with other officers.

5. Geographical relations. When classified by section of the country from which they were graduated or certified, or in which they practiced, these medical officers exhibit substantial differences in intelligence, earnings and experience. Generally speaking, the northeast, the central and the northwest sections of the country show superiority over the south and south central sections.

Intelligence and earnings vary also with the population of the community in which the medical officer (as civilian, of course) practices. The order of increasing values for intelligence is rural, urban, metropolitan; that for earnings, rural, metropolitan, urban.

6. Earnings. The annual earnings reported by these medical men vary signally with geographical location, population of community, professional specialty, experience and medical school. The correlation between intelligence and earnings is extremely low.

7. Military relations.—Medical officers of the Regular Army Medical Corps and of the National Guard achieved somewhat higher intelligence ratings than those of the Medical Reserve Corps.

Intelligence is highly correlated with rank in the Medical Corps. This indicates, to the credit of the Medical Department, that superior intelligence tends to dominate in the rank of major and above. Promotion also depends to a significant degree on intellectual capacity, as is indicated by the intelligence ratings of promoted versus non-promoted officers.

The data of this report justify the statement that the Medical Corps obtained the services of the ablest as well as the weakest men of the profession. Had the latter been eliminated by a rigorous procedure of intelligence tests, combined with professional examination, the status of the group would undoubtedly have compared favorably with that of any other professional group in the army.

8. Membership in societies. The typical medical officer of this group claims membership in two or three medical societies, one of which is usually the American Medical Association.

III. Concerning Medical Schools

1. Classification.-More than 130 medical schools are represented by the 2507 medical officers statistically considered. The numbers from these schools vary from 1 to 118. Grouping of the schools for statistical purposes was necessitated by the small number of individuals from most institutions. Five classifications have been made: By geographical location, by size (number of stu

dents registered in 1916-1917), by entrance requirements, by American Medical Association rating, and by medical sect.

2. Geographical classification.—The intelligence ratings and earnings of graduates from schools in different sections of the country correspond in general to the same information for the medical men resident in those sections.

3. Classification by size. The schools represented in the medical group were separated according to size into 8 divisions ranging from those having less than 50 students in 1916-1917 to those having 400 or more. The men graduated from the larger institutions make, on the whole, a somewhat higher intelligence rating on examination alpha than those graduated from the smaller. Earnings, on the other hand, are not closely correlated with the size of the school.

4. Classification by entrance requirements. This classification was made on the basis of requirements enforced in 1916-1917. The intelligence of the medical officer is highly correlated with the standard of entrance requirements of the school from which he was graduated. The median score, in army examination alpha, of graduates from schools requiring but one year of college work in addition to high school graduation is 118.7, whereas that of graduates from schools requiring more than 3 years of college work is 154.2, a difference of 35.5 points. The earnings reported by men from schools with high entrance requirements are also strikingly larger than those from schools with low entrance requirements.

5. Classification according to rating of the American Medical Association. The difference in median alpha scores, between graduates of schools rated "A" by the American Medical Association and those rated "C," is 17.3 points, which, though significant, is less than half as great as the difference between schools of the highest and lowest entrance requirements. The difference in earnings between classes "A" and "C" is comparatively small.

6. Classification by medical sect.-In both intelligence scores and earnings the graduates from homeopathic schools stand as much above the eclectic schools as the class "A" schools are above the class "C" schools. Graduates from "regular" schools fall approximately half way between the other two.

7. Comparison of schools. A detailed comparison (table 43) of the graduates of the 18 schools which were represented in the medical group by more than 35 students each shows that the

median intelligence rating is A for seven schools. Median earnings of $5000 or over are reported by the graduates of eight schools. The southern schools on the whole show lower scores, less schooling, lower earnings and fewer promotions than the northern.

HISTORICAL STATEMENT

The psychological examination of officers in the United States Army very promptly indicated that the intellectual status of medical officers was less satisfactory than that of officers of several other arms of the military service. Colonel Henry A. Shaw, of the Regular Army Medical Corps, invited the attention of the Surgeon General to this fact in a report, submitted November 16, 1917, which he based upon observation of the psychological service and data of examination at Camp Lee, Virginia.1

Table 1, quoted from Colonel Shaw's report, indicates the remarkable differences in frequency of A and also of A and B grades, that is, very superior and superior intelligence, for officers of different arms of the service. Thus, for medical officers there are 27% of A grades; for engineers, 66%. Colonel Shaw remarks:

Comment on these figures is unnecessary. They speak for themselves. The only question is whether or not they represent a true state of affairs. With reference to the comparative efficiency of the officers of the various arms of the service I am not in a position to judge. I am of the opinion, however, that the order of mentality as shown by the psychological scores is fairly close to the truth. It is reasonable to believe that the engineers have succeeded in attaching to their corps a larger number of technically. trained young men than any other branch of the service. It is also probable that the officers' training camps have drawn into the commissioned grades a larger number of college-trained men than either the Quartermaster or the Medical Corps.

The psychological findings, Colonel Shaw's comment thereupon and his recommendations to the Surgeon General aroused the critical interest of the medical profession. It was variously suggested that differences in age, education, basis of selection, or applicability of the intelligence tests might be responsible for the relatively unsatisfactory showing of medical officers. Because of the general interest in these results and the discussion which they provoked, their later correction or confirmation became important.

1 On November 19 Colonel Shaw transmitted to the Surgeon General a special report on the psychological ratings of medical officers. This report is quoted entire in "Psychological Examining in the United States Army" (official report), Memoirs of the National Academy of Sciences, 15 (22-23). (In press.)

It is proposed to present in this report results which were secured during 1917 and 1918 in a large number of army camps and which undoubtedly represent fairly the officer personnel of the army with respect alike to its medical component and the other arms of the service. Colonel Shaw's report, by contrast, was based upon preliminary results in only one camp.

TABLE 1

Distribution of intelligence (Letter grades A to D) in different arms of the military service1

Although approximately 43,000 officers were given psychological examination, the Division of Psychology of the Surgeon General's Office, because of limited resources, was able to use only about 15,000 of these records for statistical purposes. Of the 15,000 about 3000 were the records of medical officers. The intelligence measurements available for these men were studied by the aid of the Hollerith method and a very brief and general statement on the status of medical officers was prepared for the official report to the Surgeon General concerning psychological examining in the army (see tables 2 and 3 herewith). While this work was in progress Dr. Robert H. Halsey of New York suggested to the Chief of the Division of Psychology the importance of arranging for a careful and thorough-going study of the data on medical officers which were available in army records. Following this suggestion, the Division of Psychology secured the coöperation of the Division of Medicine and Related Sciences of the National Research Council, which supplied adequate funds for the work.

It was promptly arranged that Miss Margaret V. Cobb, under the supervision of the Chief of the Division of Psychology of the Sur1 The letter grades are defined on page 467. The data of this table were obtained with army group-examination a, which was later revised and designated examination alpha, given to 1,166 officers, Camp Lee, Va. Percentages are taken from Table 1, p. 22, of the official report cited above.