At the same time, as citizens, you want to be one of those who help to make more general and more real this feeling of responsibility for the children and for the generations yet to come.

The problem of eugenics is twofold: To know the truth about the influence of inheritance, and to apply this truth to the benefit of the future generations of our race. The goal is high; the certainty that it is also distant should not daunt us. It is enough that we know that public opinion, based on sound eugenic teaching can do much, and that how much it will do depends on each individual one of us. The citizen who performs his part in the formation of this public opinion will be content if he will learn of nature the lesson of quiet work:

"One lesson of two duties kept at one,

Though the loud world proclaim their enmity -
Of toil unsevered from tranquillity;

Of labor, that in lasting fruit outgrows
Far noisier schemes, accomplished in repose,
Too great for haste, too high for rivalry."

XII

EUGENICS: WITH SPECIAL REFERENCE TO INTELLECT AND CHARACTER

EDWARD L. THORNDIKE

By eugenics is meant, as you all know, the improvement of mankind by breeding. It has been decided by those responsible for this lecture 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 emphasise the extent of these differences. Whether we take some trivial function - such as memory for isolated words, or delicacy of discrimination of pitchor 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 reputemen differ widely. Samples of the amount and distribution of such differences are given in Charts 1, 2 and 3. Chart I 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.

Examples done correctly in 15 minutes.

CHART I. THE RELATIVE FREQUENCIES OF DIFFERENT DEGREES OF ABILITY IN ADDITION IN THE CASE OF FOURTH-GRADE PUPILS.

O-1 percent

10

20

30

40

50

Gain made in examples done correctly in 10 minutes
CHART 2. THE RELATIVE FREQUENCIES OF DIFFERENT AMOUNTS OF
GAIN FROM FIFTY MINUTES OF PRACTISE IN DIVISION, IN THE CASE
OF PUPILS OF THE SAME SCHOOL GRADE.

Chart 2 shows that when four hundred children who had had similar school training were given each the same amount of practice in certain work in division,

ן

some improved not at all, and others enormously. Chart 3 shows that of children in the same city all of the same year-age (thirteen), some have done the work of the eight grades of the elementary 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.

0-1 per cent

I I I N ▼ ■ VII VII IMS IIMS.
Grade reached at the age of 13.

CHART 3 THE RELATIVE FREQUENCIES OF DIFFERENT AMOUNTS OF
PROGRESS IN SCHOOL OF THIRTEEN-YEAR-OLD CHILDREN.

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 constitutions 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 also due in part to differences. in environment, circumstances, training-one sort of

home-life being more favourable than another to progress through school, for example. Each advance in the study of individual differences, however, shows that differences in maturity and differences in the circumstances of nurture account for only a small fraction of the differences actually found in individuals of the same general environment of an American city in 19001912. Long before a child begins his schooling, or a man his work at trade or profession, or a woman her management of a home-long indeed before they are born their superiority or inferiority to others of the same environmental advantages is determined by the constitution of the germs and ova whence they spring, and which, at the start of their individual lives, they

are.

Of the score or more of important studies of the causes of individual differences which have been made since Francis Galton led the way, I do not find one that lends any support to the doctrine of human initial equality, total or approximate. On the contrary, every one of them gives evidence that if the thousand babies born this week in New York City were given equal opportunity they would still differ in much the same way and to much the same extent as they will in fact differ.

We find, for instance, that the children of certain families rank very much higher in certain psychological tests of perception, association and the like, than the children of certain other families. Now if this difference were due to the difference between the two groups of families in environment-in ideals, customs, hygienic conditions and the like it should increase greatly with the age of the children in some rough pro