736 



MEMOIRS NATIONAL ACADEMY OF SCIENCES. 



[Vol. XV, 



negro recruits as follows: "The lighter class contained those whose color indicated that they 

 were true mulattoes or persons of a larger proportion of white blood than true mulattoes. 

 The darker class contained pure negroes and those whose skin color indicated that they had a 

 smaller proportion of white blood than true mulattoes. The classification was made by the 

 various examiners of the groups. 



"In alpha, the lighter negroes obtained a median score of 50 ; the darker obtained a median 

 of 30. In beta, the lighter negroes obtained a median score of 36; the darker obtained a 

 median of 29. 



"The percentage of darker negroes was greater among the illiterates than among the 

 literates. In the alpha group 82 per cent of the negroes were darker and 18 per cent lighter; 

 in the beta group 8S.5 per cent of the negroes were darker and 11.5 per cent were lighter." 



90 



©O- 



70 



60 



50 



AO 



SO 



to 



IO- 

 O 



ALPHA 



NO. CASES 



90- 



©O- 



70 



60- 



50- 



40- 



SO- 



20- |4.| 



1296 



10 



o 



56 



BETA 

 25 O 



3.4 



D C- 



C+ 6 



Fiq. 23. Percentage distributions by letter grades on two examinations of negroes who took (a) alpha and then beta; (6) beta and then the point 



scale; (c) beta and then the Stanford-Binet examination. 



Hollerith sortings were made of cases taking both alpha and beta, also of cases taking 

 both beta and individual examination. The men who took more than one examination were, 

 of course, almost entirely men who had made a failure or a very low grade on the first. It is 

 desired to compare the results of the first and second examination in order to see how the second 

 examination redistributes the men who made low grades on the first. Only three tables have a 

 sufficiently large number of cases to warrant their inclusion and consideration here. These 

 are tables 270, 271, and 272. The results are given graphically in figure 23. The first part 

 of this chart (a) shows how beta redistributed 1,296 men who had already taken alpha. The 

 distributions are made by letter grade and the height of the columns represents the percentage 

 of cases making a given grade. It will be seen that most of the alpha men are of D— grade. 

 When these same men take beta, only 14.1 per cent of them fail to make scores higher than 

 D— . The number who rate as D and therefore still inferior is large, but there are approxi- 

 mately 30 per cent who rate above D instead of 3 per cent so rating on alpha. Altogether the 

 distribution effected by beta is quite a significant improvement over that effected by alpha. 



