In discussing the results, those measurements given by the group method will be first considered. They are treated in their approximate order of complexity, as numbered and tabulated on page 139.

(1) Accuracy In Tracing

The data for this simple motor test are embodied in tables 147 and 148 for Squads A and B, respectively. At the left in chronological order are found the dates for the evening experimental sessions. The data for the various subjects are arranged in columns from left to right. The headings of these columns are the abbreviated names of the subjects. The subjects are always listed in the same order, that is, with Squad A, beginning with Bro and ending with Fre. The latter subject served the shortest time, that is, the fewest number of sessions of any one in either squad, and with some measurements there are no data for him. Kon, who was originally a member of Squad B, replaced Fre, who left Squad A on October 26. Kon served his first session October 6 as subject No. 5 in Squad B. His data for this evening are transferred to the tables for Squad A and given under the date of September 29, the first session for Squad A. Fre was present at the Laboratory at the second session with Squad A, that is, October 13, so that Kon actually came into Squad A at a later date. He began his diet reduction on October 30, and since the percentage reduction was very rapid, it seems best not to average the results for Kon with Squad A. Spe, owing to illness (see p. 360), was not present at the Laboratory after December 8, and his place was not filled. In Squad B, Fis was in the hospital for an operation for hernia on December 15. McM was not taken into Squad B until after their first session on October 6, when he replaced Kon. In the early part of January he had some digestive difficulties which made it seem unwise for him to serve as a subject during the severe food reduction for this squad. His place was taken by Kim, who had served on January 5 in place of Lon. Lon on that date was ill and it was possible that he might not be able to continue as a subject in Squad B. Mac was called into the Government service during the Christmas vacation, receiving his notification only the day before it was necessary for him to appear at camp. We were not informed of his call until after he had been at camp several days. An arrangement was made with the commandant to release him until the first of February. The subject thought that this short interval in college would be of little value, and, as he was well started in his work, he did not see fit to leave it to carry on the experiment. A substitute was found in Sch, who served in the last four sessions of Squad B. Tho, in returning from his Christmas vacation, was delayed, and because of transportation conditions could not reach the Laboratory on the evening of January 5 until after the group work had been completed. These breaks or irregularities in all our psychological data occur in the succeeding tables for other measurements and will not need special mention there.

Table 147. - Squad A - Accuracy Of Movement In Tracing. (Average Number Of Errors Per Line)

1 This average does not include Kon, Spe and Fre. 2 The one normal experiment, Sept. 29, is not included in the average.

3 It is worthy of notice that Vea, who made this best score and one of the best average scores, suffered most from cold hands during the low-diet period.

The values given in tables 147 and 148 show the average number of errors per line. Each average represents five lines, as the test blank was so made up. In table 147, the scores range from 0.6 to 10.8. The total average is approximately 5. The individual differences may be seen in the averages in the bottom line of the table. Each value is from the nine low-diet results in the column above. As September 29 was normal, it is never averaged with the other dates. The average at the bottom of the table covers the low-diet period and for convenience is called low-diet average. Tom, Bro, and Vea made the best scores. The values were: 2.0, 2.2, and 2.3. Tom was very consistent throughout. He made decidedly the best records in the early sessions, but did not keep his lead owing, no doubt, to his physical condition as a result of the operation which came near the end of the experiment. The scores of Pea may have been affected by the fact that a few hours before he came to Boston he usually engaged in a cross-country race. It may be of significance that when Kon showed the poor score of 10.8, he was practically fasting.

In table 148, which gives the results for Squad B, the range of variation is about the same, that is, from 0.6 to 11.7. The upper 5 dates at the left hand of the table were normal; the 3 lower ones were during food reduction. The two groups of records have been averaged separately for each individual. The best records were made by Sne, How, and Tho. The low-diet averages for each individual, with the exception of a few cases, show that during the low diet the subjects continued to improve in the test, with the result that they made fewer errors. This was not the case with Har, who had a normal average of 3.7 and a low-diet average of 5.1, and Liv, who averaged 3.5 under both conditions. The average score for both groups of men, Squads A and B, is, if anything, a little smaller than the scores reported by Fisher and Berry, who used this same test in an investigation carried out at the International Y. M. C. A. College in 1915.1

Table 148. - Squad B - Accuracy Of Movement In Tracing. (Average Number Of Errors Per Line)

1 This average does not include McM, Kim, Mac, and Sch.

The average results for both squads, considered together, are shown in figure 102. The upper horizontal line of dates at the top of the figure, beginning September 29, October 13, etc., is for the sessions of Squad A (see table 147). September 29 is the only normal date, the others representing a reduced diet. The lower horizontal line of dates beginning October 6, November 3, etc., is for the sessions of Squad B. The first five of these, that is, until and including January 5, were normal sessions (uncontrolled diet). The last three, January 13, 19, and 27, were under conditions of reduced diet when the reduction was much more pronounced than usual for Squad A. On September 29, the one normal date, Squad A had an average value of 5.7. On the two succeeding dates, October 13 and 27, separated by 2-week intervals, the average errors were somewhat larger, 5.9 and 6.0; several of the men made their poorest records on October 27. Other subjects - Can, Gul, and Pea - showed very little improvement over the previous two sessions. The improvement was not what would be expected nor equal to that found with Squad B and shown by the curve in figure 102. Squad B, it is true, showed no improvement between the first two sessions, but a period of four weeks elapsed between the two experiments of October 6 and November 3. Between the second and third sessions the period was exactly two weeks; much improvement was shown, the errors being reduced to 4.6. Between sessions 3 and 4 a period of a month again elapsed and no improvement is shown. The same is to be said for sessions 4 and 5, which were separated by 3 weeks. When the sessions were separated by two weeks or less an improvement in accurate tracing with Squad B almost always resulted. While the two curves start at nearly the same point, it is evident that, considering the number of practices and the intermissions, Squad B made definitely the better performance. Squad A did as well as Squad B at the sixth session, that is December 8 for Squad A and January 13 for Squad B. This abnormal rise for Squad A is associated with the more comfortable period in the early part of December, when the men were receiving more food. December 19, which shows a depression in the curve, was probably influenced by the fact that the observations on this date immediately preceded the Christmas vacation. On January 12 the net energy given the subjects was small to counterbalance the overeating during the vacation period. On the last two dates, January 26 and February 2, the group made their best records. It is unfortunate that the experiments with Squad B did not come with the same regularity and were not equal in number to those with A. It is, furthermore, unfortunate that the last normal date for this squad (January 5) was the immediate close of the vacation period and was separated from their previous experiment by 3 weeks. The conditions in the two observations preceding the food reduction with Squad B are not favorable for revealing the influence of the 3 weeks of reduced diet. Notwithstanding this, it is evident from the curve in figure 102 that up to the sixth experiment, in spite of the longer intervals between experiments, Squad B shows a superior performance to Squad A. At the sixth experiment, the first in the reduced-diet period for Squad B, they are slightly poorer than Squad A, and in their next two, January 19 and 27, while they improve over January 13, they do not reach the record of Squad A for January 26 and February 2, which, considering their superiority over Squad A in experiments 2 to 5 inclusive, they might reasonably have been expected to reach.

1 Fisher and Berry. Physical Effect of Smoking, New York 1917. These authors state that a fountain pen was used for drawing between the lines, that a metronome was employed to time the men, and that 17 seconds were allowed for each line. Professor Berry informs us that " 17" is a misprint and the time should be 14 seconds, the same as that used in our investigation.

It seems justifiable to conclude, although the results for Squad B, unless interpreted in the light of certain modifying conditions, will not entirely support the statement, that with Squad A, particularly during the months of October and November, the motor functions involved in steadiness in tracing as used in this test were interfered with by the reduced diet, since the squad as a whole did not do such accurate work or make such rapid improvement in the test as would have been expected of them under normal conditions.