Karl Pearson 
101 
mean weight appears to be greater at the latter age, and possibly in mere exami- 
nation activity quantity may reckon more than quality in brains as well as it 
frequently does in marking. It might be of value to determine the partial 
correlation when allowance was made for the number of times the candidate had 
entered. 
Illustration III. Conscientiousness and Cephalic Index. It is well known that 
the cephalic index remains fairly constant from about 2 or 3 years old onwards. 
It is further a marked racial character. Folklore associates with various grades of 
honesty the local races of this country. It seemed accordingly worth while testing 
whether my school records gave any association between cephalic index and 
conscientiousness. The children measured were divided into those whose con- 
scientiousness was " Keen," " Dull " or " Betwixt." The latter class were about 
147o of the total and we divided them equally between the "keen" and "dull" 
classes. The result is given in the table below. We obtained for 1534 boys: 
Mean Cephalic Index of the " Dull " group 78-8876. 
Mean Cephalic Index of all Boys 78-8801. 
Standard Deviation for all Boys 3-2929. 
Conscientiousness and Cephalic Index of Boys. 
Conscientiousness 
Conscientiousness 
Cephalic 
Cephalic 
Index 
Index 
Keen 
Dull 
Totals 
Keen 
Dull 
Totals 
66 
1 
1 
79 
127 
62 
189 
67 
SO 
122 
58 
180 
68 
1 
1 
2 
81 
99 
44 
143 
69 
4 
1 
5 
82 
86 
24 
no 
70 
5 
1 
6 
83 
55 
84 
71 
7 
2 
9 
8Jf 
28 
21 
49 
72 
11 
6 
17 
85 
18 
11 
29 
73 
26 
10 
36 
86 
16 
7 
23 
74 
35 
18 
53 
87 
8 
1 
9 
75 
58 
25 
83 
88 
3 
3 
76 
81 
40 
121 
89 
1 
1 
77 
110 
58 
168 
90 
1 
1 
2 
78 
145 
64 
209 
91 
2 
2 
Totals 
1049 
485 
1534 
Further, i (1 - a) = -3162) . . 
i (! + «)= •6838} g>vmg. = -3oo8. 
Thus we find p/a, 4- ^-^^^ = + -0023, 
5/(72 = 1 1 252. 
And finally r=-|--0020. 
