552 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



reduction in diet as these subjects underwent should be investigated 

 for its own sake and can not be rightfully assumed as a normal. Under 

 peace-time circumstances the men composing Squad A would usually 

 have remained in college for two or three months subsequent to the 

 experiment, a period which supposedly would have allowed them to 

 become adjusted to their natural dietetic habits. At the end of such 

 a period they doubtless could have been obtained for one or two 

 sessions of normal measurements. It is needless to explain the im- 

 practicability of such a plan in 1918. In fact, it was exceedingly 

 difficult to hold the subjects together until the end of the diet experi- 

 ment on February 3, and in some cases it was necessary to have men 

 excused temporarily from the Government service. Very shortly 

 after the end of the experiment, 6 of the men in Squad A had left 

 college and were in various fields of Government work. 



Squad B did not begin the reduced diet until January 8, and re- 

 mained on the low diet about 3 weeks, or until January 28. Hence, 

 a greater part of the measurements with this squad were under sup- 

 posedly normal conditions. If it is ever permissible with squads of 

 10 men to take the normal psychological results for one group and 

 assume them to be a normal measure for another group, then it is 

 permissible here. The men composing Squad A and Squad B came 

 from the larger homogeneous body at the International Y.M.C.A. 

 College. The men were not selected for one squad or the other on a 

 basis of scholarship; in fact, their scholastic records show that the 

 groups rank about evenly in this regard. Furthermore the squads 

 compared very well in age and physical abihty, although, in general, 

 upper classmen were taken for Squad A. Doubtless, as there was some 

 group spirit, each squad considered itself superior to the other, but as 

 subjects for laboratory experiments in psychological measurements 

 there was no prominent difference between them. Squad A had some- 

 what the advantage on the side of laboratory practice, since, in the 

 early fall, they came regularly every 2 weeks, while the sessions with 

 Squad B were sometimes separated by 4 weeks and the latter squad 

 had a total number of 8 laboratory sessions, while the former squad 

 had 10. (See chronological record, p. 60.) 



With some of the measurements there are already at hand con- 

 siderable normal data for comparison purposes. In the spring and 

 early summer of 1917 a series of neuro-muscular and psychological 

 observations were carried out at the Nutrition Laboratory with a group 

 of 63 college men who were prospective aviators attending an aviation 

 ground school. These subjects were mostly upper classmen or gradu- 

 ates from Harvard, Yale, and other leading universities. They were 

 in many respects a picked group of men who had passed the requisite 

 physical examination. They served one normal session of approxi- 

 mately H hours, which followed the evening meal as did the sessions 



