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MEMOIRS NATIONAL ACADEMY OF SCIENCES. 



[Vol. XV, 



Tables 368, 369, and 370 give comparisons of officer groups at Camps Taylor, Greenleaf , and 

 Lee. In all cases there is a definite trend toward decreasing score with increasing age. These 

 tables are based on examination a. 



Table 368. — Relation of intelligence ratings to age of 1,192 white officers, Camp Taylor. Median scores of examination a. 



Table 369. — Relation of intelligence rating to age of 5,742 medical officers, Camp Greenleaf. Median scores of examination a. 



2,475 MEDICAL OFFICERS OF DRAFT AGE. 



Table 370. — Relation of intelligence rating to age of 778 white officers, Camp Lee. Median scores of examination a. 



Camp Devens reported the data from examination a that are summarized in table 371. 

 Here the age distribution of medical officers (146 cases) is approximately normal. Its median 

 is at 37 years. The median age of infantry officers is 25.4. Tetrachoric correlations of age 

 with score gave —0.0107 for medical officers and +0.12 for infantry officers. The modes of the 

 distributions for all officers and for the infantry group fall near age 25 with decidedly skewed 

 distributions. The small number of cases in the higher age groups makes comparisons uncertain. 

 Nevertheless, the drift is again in the direction of decreasing score with increasing age. If we 

 accept the criterion that a difference between means which is three times its probable error is 

 significant, we find that the age group 21-25 is superior to the group 26-30 or to any higher 

 group. Above 35 years in these data there is no significant difference between age groups. 



