EUGENICS 125 



EUGENICS: WITH SPECIAL BEFEEENCE TO INTELLECT 



AND CHAEACTEE 1 



Bx Pbofessob EDWARD L. THORNDIKE 



TEACHERS COLLEGE, COLUMBIA UNIVERSITY 



BY" eugenics is meant, as yon all know, the improvement of mankind 

 by breeding. It has been decided by those responsible for this 

 lecture — Mrs. Huntington Wilson and the president and trustees of the 

 university — that its topic shall be the intellectual and moral, rather 

 than the physical, improvement of the human stock. 



Common observation teaches that individuals of the same sex and 

 age differ widely in intellect, character and achievement. The more 

 systematic and exact observations made by scientific students of human 

 nature emphasize the extent of these differences. Whether we take 

 some trivial function — such as memory for isolated words, or delicacy 

 of discrimination of pitch — or take some broad symptom of man's 

 nature, such as his rate of progress through school, or ability in tests of 

 abstract intellect, or even his general intellectual and moral repute — 

 men differ widely. Samples of the amount and distribution of such 

 differences are given in Charts 1, 2 and 3. Chart 1 relates that of 732 

 children who had studied arithmetic equally long, one could get over a 

 hundred examples done correctly in fifteen minutes, while others could 

 not get correct answers to five. Even if we leave out of account the 

 top three per cent., covering all the records of 60 or over, we have some 

 children achieving twenty-five times as many correct answers as other 

 children. 



Chart 2 shows that when four hundred children who had had similar 

 school training were given each the same amount of practise in certain 

 work in division, some improve not at all, and others enormously. Chart 

 3 shows that of children in the same school all of the same year-age 

 (thirteen), some have done the work of the eight grades of the elemen- 

 tary school and of one or two years of the high school, while others have 

 not completed the work of a single year. Still less competence at 

 intellectual tasks could be found by including children from asylums 

 for imbeciles and idiots. 



The differences thus found amongst individuals of the same sex and 

 age are due in large measure to original, inborn characteristics of the 

 intellectual and moral constitution of the individuals in question. They 

 are, it is true, in part due to differences in maturity — one thirteen-year- 

 old being further advanced in development than another. They are 



1 A lecture given at Columbia University, in March, 1913. 



