PSYCHOLOGICAL MEASUREMENTS. 



627 



112" III 2" IV2" V2" 



quence it did not seem justifiable to increase the size of tables 182 

 to 185 fivefold by printing these 2-second data. 



The averages are shown diagrammatically in figure 121. To avoid 

 complicating the figure, the results for evening and morning records 

 are grouped separately. The columns or ordinates from left to right 

 are headed I 2 seconds, II 2 seconds, etc. Each curve has a designa- 

 tion. The regularity of decline in the seven curves tells its own story 

 without further discussion. The curves {A and B) for the evening 

 normals are not so straight as are those for the low-diet results {A' and 

 B'). The fall from one 2 seconds to the next 2 seconds is uniformly 0.3 

 or 0.4 of a complete finger movement. Had we only the evening 

 data of Squad B, it might be thought that early fatigue developed a 

 Httle more slowly under conditions of food reduction and at the lower 

 level of performance which then obtains. The results with Squad A 

 and the morning results with B do not agree; there is thus no con- 

 sistent indica- 

 tion of a change Evening Morning 

 in fatigue de- is 

 velopment or 

 latency with 

 the food reduc- 

 tion. The dif- 

 ference in num- 

 ber of finger 

 m ovements 

 performed un- 

 der normal and 

 low-diet condi- 

 tions is sub- 

 stantially the 

 same whether 

 one takes 2, 4, 



6, 8, or 10 second records. It is apparently a difference in level 

 rather than one of readiness or fatigue of the process. 



It is clear that there was a decrease in the efficiency of the motor 

 coordination of finger movements which quite evidently resulted from 

 the food reduction. The decrease, with fluctuation, is shown in the 

 case of Squad A in both the evening and morning records and was very 

 prominent with Squad B during the three weeks' period of food reduc- 

 tion. Judging from the evening records of Squa,d A, the decrease in 

 the finger movements incident to the food reduction was fully 5 per 

 cent.^ Squad A during the greater number of experiments were below 

 B, even though they were normally capable of a faster rate than B, 

 as was shown on September 29. 



Fig. 121. 



-Number of finger movements performed in successive 

 2-second intervals. 



The scale at the left shows complete oscillations. Results for evening 

 and morning records are diagrammed separately. A, Squad A 

 normal; B, Squad B normal; A', Squad Aon low diet; B', Squad 

 B on low diet. 



^Four of the evening experiments during food reduction show a decrement as great or greater 

 than 6.4 per cent. 



