654 



MEMOIRS NATIONAL ACADEMY OF SCIENCES. 



Table 165. — Distributions on the combined scale of the main groups of the sample. 



[Vol. XV, 



Combined scale in class intervals. 



25.0-25.9. 

 24.0-24.9. 

 23.0-23.9. 

 22.0-22.9. 

 21.0-21.9. 

 20.0-20.9. 

 19.0-19.9. 

 18.0-18.9. 

 17.0-17.9. 

 16.0-16.9. 

 15.0-15.9. 

 14.0-14.9. 

 13.0-13.9. 

 12.0-12.9. 

 11.0-11.9. 

 10.0-10.9. 



9.0-9.9. 



8.0-8.9. 



7.0- 7.9. 



6.0- 6.9. 



5.0- 5.9. 



4.0- 4.9. 



3.0-3.9. 



2.0-2.9. 



1.0- 1.9. 



0.0-0.0. 



Cases. 



Means 



Standard deviations 



Mean in mental age years. 



Groups I. II, 

 anfi III, 



white draft. 



Frequency. 



6 



15 



122 



437 



1,000 



1,787 



2,953 



4,580 



6,634 



9,050 



11,572 



14,229 



13,940 



10,036 



6,887 



4,770 



2,951 



1,681 



808 



333 



122 



38 



11 



3 



93,965 



13.46 

 2.94 

 13.08 



Groups IV 



andV, 



colored draft. 



Frequency. 















2 



7 



17 



50 



91 



182 



332 



607 



1,132 



1,776 



2,283 



2,662 



2,903 



2,584 



1,953 



1,216 



646 



290 



110 



40 



7 



18,892 



2.68 

 10.37 



Group VIII, 



white 



officers. 



Frequency. 



1 



6 



106 



612 



1,648 



2,522 



2,836 



2,698 



2,155 



1,454 



837 



412 



179 



60 



14 



3 



1 



15,544 



18.84 

 2.10 

 17.26 



Development 



battalions 

 (Group VIII). 



Frequency. 







1 



3 



7 



16 



27 



47 



78 



121 



175 



230 



270 



251 



187 



149 



130 



102 



76 



52 



28 



15 



1,973 



12.71 

 3.32 

 12.49 



The means in mental ages were calculated from the regression of combined scale on mental age, which is: M. A. (in years)«=0.778 C. S. + 2.( 

 They are given in order that persons accustomed to thinking in terms of mental age can readily adjust themselves to the combined scale. 



Table 166. — Variables: Alpha score X beta score. Groups J, II, III: White draft. 



For men who took beta following alpha, or who took alpha, beta, and an individual examination. 



Table 166 exhibits the relation between alpha and beta for all individuals in Groups I, II, 

 III of the principal sample who had both of these examinations. The alpha distribution of 

 this table was turned into the combined scale by way of table 159, and the beta distribution 

 by way of table 162. The results are given in table 167. 



