334 Prof. K. Pearson. On the Correlation of Intellectual 



excessive, and we owe entirely to the kindness of Mr. W. H. Macaulay, 

 of King's College, the presentation of our problem to the authorities 

 of the University Registry and the arrangements for supplying the 

 necessary data. We have heartily to thank both him and the officers 

 at the Registry for aid in this matter. We thus obtained the addition 

 to our cards of the exact nature, honours or poll, class-place, subject 

 (science, theology, literature, &c.) of the degree taken by each individual. 

 We were then provided with a most valuable mass of material for 

 testing how far any of the chief physical characters are correlated with 

 a fairly comprehensive scale of ability, or with the special intellectual 

 tastes of the measured. 



There is work in this mass of material, reducing and classifying it, 

 for one or two good calculators during several years. At present no 

 attempt has been made to reduce it, except in one special direction 

 that of the correlation of intellectual ability with the shape of the 

 head. This is the subject of the present preliminary notice. The tables 

 in this case were prepared partly by myself and partly by my assistant, 

 Mr. E. Blanchard, B.A., of Caius College. Nearly the whole work 

 of calculation is due to Dr. Alice Lee and Miss M. A. Lewenz, B.A. 

 The conclusions, therefore, are a co-operative product of the biometric 

 workers associated with me at University College, London. 



(2.) Dr. Lee, in a paper " A First Study of the Correlation of the 

 Human Skull," published in the Phil. Trans.,' A, vol. 196, pp. 225-264, 

 has presented a considerable amount of evidence to show that " there 

 is no marked correlation between skull capacity and intellectual 

 power " (p. 259). We have found this result frequently contested 

 and a very definite statement made that able men have large heads. 

 We cannot find, however, that there are really reliable statistics, 

 adequately treated, which in any way prove this general statement. 

 It is perfectly true that the professional classes in this country have a 

 rather larger head than the hand-working classes, and the former are 

 rather more intellectual ; but they are taller and physically more 

 developed also, and the whole difference is most probably due to better 

 nurture. One of our number, Dr. W. R. Macdonell, has recently 

 shown that the head of the Cambridge undergraduate is larger than 

 the head of the criminal population,* but any deduction from a mixture 

 of these two classes (that ability is correlated with size of head) 

 would be wholly misleading. We must take a homogeneous class of 

 approximately the same nurture and habits, and inquire whether there 

 is any correlation between ability and size of head within this class. 

 It is this which we have attempted to do with the Cambridge statistics. 



(3.) For our present purposes we have made a very broad classifica- 

 tion of Cambridge men into poll and honours men. There are occasion- 

 ally poll men who undoubtedly are intellectually stronger than some 

 * " On Criminal Anthropometry . . .," ' Biometrika,' vol. 1, pp. 185, 188, &c. 



