504 THE POPULAR SCIENCE MONTHLY 



FAMILIES OP AMEEICAN MEN OF SCIENCE 



By J. McKEEN CATTELL 



IN a series of articles entitled " A Statistical Study of American Men 

 of Science," printed in Science in 1906 and 1910 and as an appen- 

 dix to "The Biographical Directory of American Men of Science," 

 methods were explained by which the thousand leading scientific men 

 of the United States had been selected and arranged in the order of the 

 merit of their work. Studies were made of the measurement of scien- 

 tific performance, of the origin and distribution of scientific men, and 

 of the changes which occurred during an interval of several years. 

 Data have now been gathered in regard to the families of the men of 

 science previously selected. In our present state of ignorance a statis- 

 tical study of any homogeneous and objectively chosen group should be 

 of value, both as a contribution to psychological and vital statistics in 

 general and for comparison with other groups which may be similarly 

 studied. Scientific men form a desirable group for such study as, on the 

 one hand, they may be assumed to be willing and competent to supply 

 the information and, on the other hand, knowledge concerning the con- 

 ditions favorable to scientific performance may have important practical 

 applications. 



Of one thousand one hundred and fifty-four scientific men from whom 

 information in regard to their families was requested 1,036 replied and 

 118 did not. Of the replies 16 were blank, sometimes accompanied by 

 the explanation that the information was not readily attainable or the 

 like, 7 were to the effect that the information would be sent later or the 

 like, 13 were received too late, 25 were very imperfect, 975 were usable 

 and in most cases complete. This is an unusually full reply to a ques- 

 tionnaire. For example, in answer to an inquiry in regard to note- 

 worthy relatives addressed to 467 fellows of the Eoyal Society, Sir 

 Francis Galton received 207 useful replies, and the completely available 

 returns "scarcely exceeded 100." In such cases it is desirable that re- 

 turns should be complete in order to avoid the selection of a special 

 class. Thus, when people are asked whether they have noteworthy rel- 

 atives, those having them are more likely to reply than others, and the 

 percentage of positive replies may give no definite information in re- 

 gard to the frequency. In the present case it appears, froni examina- 

 tion of the names of the ten per cent, who failed to reply, that there 

 was no group that would affect appreciably the result of the inquiry. 



