i6 MAL-NUTRITION AND THE TEACHER'S 



It may be gravely doubted whether he even placed his 

 hand, indeed, on the heads of the 82,000 children passed as 

 ' normal '. No growth curves were found, no allowance 

 made for differences between the sexes, and no definite 

 standard for large or small heads ever formulated. Yet 

 in Mr. Yule's analysis of Dr. Warner's data he has not 

 a word of criticism for methods such as this. 



But we can go further. In Table XVI of his Report 

 (p. 103) Dr. Warner finds that of the children with small 

 crania, 41-4 % of the boys and 45-5 % of the girls are ' men- 

 tally dull ' as compared with 8-3 % and 6-^ % in the whole 

 series ^ investigated. There is thus apparently a very close 

 relationship between mental defect and cranial defect. Now 

 this problem has been directly investigated by Professor 

 Karl Pearson. 2 The material dealt with consisted of {a) the 

 head measurements of 1,000 Cambridge graduates, together 

 with the examinational standing of each ; and {h) the head 

 measurements of over 5,000 school children, together with 

 an estimate by the teachers of the intelligence of the 

 children. Both sets of material gave the same results, but 

 only the observations on school children will be summarized 

 here. The children were placed in six groups for intelli- 

 gence ranging from ' Quick Intelligent ' to ' Very Dull '. 

 The ' Very Dull ' formed about 2 % of the whole as com- 

 pared with 7 % of Dr. Warner s school children, who were 

 classed as ' Mentally Dull '. Thus the * Veiy Dull ' were of 

 somewhat lower intelligence than Dr. Warner's ' Mentally 

 Dull ' group. In the following Table I have extracted from 

 Professor Pearson's results the means and standard devia- 

 tions for the head length, head breadth, head height, and 



^ 1888 investigation only. 



2 R. S. Proc, vol. Ixix, pp. 333-42. R. S. Proc, vol. Ixxi, pp. 106-14. 

 Bio7netrika, vol. v, pp. 105-46. 



