CHAPTER

"acquired characters." Recent discoveries. The de-

termination of sex.

(b) Experimental breeding.

(c) Statistical methods.

The difference between changes in germ and body
cells. The uses of the word "heredity."

VI. HEREDITY AND SOCIETY

The folly of attempting to compare two essentials.

The real question is to determine what we get via the

road of heredity, what from the environment. The

inheritance of physical traits such as dwarfism, deaf-

mutism, hemophilia, classification of human beings

on basis of mental powers. Feeble-minded, normal,

genius. Evidence as to share played by heredity and

environment in reproducing these types. The relation

of genius and insanity. The frequency of genius.

Evidence that desirable traits are inherited. Illustra-

tions from royal families of Europe. The rôle of cus-

tom and law in controlling marriage. Negative

eugenics - the attempt to stop the reproduction of the

unfit. Positive eugenics - the attempt to improve the
race stock by greater care and selection in marriage.

The physical differences between groups of men.

Comparison of color of hair, eyes and skin. Stature,
head forms. The study of brain weights. The attempt
to find correlations between physical characteristics and
civilization or the possibility thereof. Difficulty of
finding a "pure race." Evidence that all great civiliza-
tions have been made up of mixed peoples. The present
population of Europe and America. The difficulty of
determining racial superiority or inferiority. Good
and bad results of intermixture of races. The con-
fusion of physical and social questions.

Various suggested classifications of the human race,
from Linnæus to Giddings.

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233

276

Appearance of sex in the organic world. Its ap-

parent value. Observed differences between the human
sexes in rate of growth, size, proportions, brain weights.
Physiological differences. Alleged bearing of these
facts on the activities of sex. Is one sex superior?
The desirability of recognizing sex differences. Sum-

mary.

IX. THE INFLUENCES OF SOCIETY UPON POPULATION

The fertility of different stocks. The falling birth-

rate. Influence of medical skill, changed industrial

life, immigration, celibacy, disease, contraceptive

measures in restricting reproduction. Effect on human

physical evolution of inventions, surgical skill, war,

religion, charity, social castes, industry, etc. Is inven-

tion checking favorable variation and creating an

artificial rather than a natural condition? Is science

and philanthropy preserving unfavorable types which

tend to reproduce faster than the superior and will in

time, therefore, drive out the better? Have social ar-

rangements destroyed the struggle for existence on

which progress depends? Is civilization destroying
itself? Does social evolution unfavorably affect pop-
ulation? Need of new ideals.

Belief and knowledge. The rise of customs. Con-
flicting moralities. Origin of social institutions
through desire to regulate human conduct. Reality of
the social environment. Personal rights. Institutions
not always beneficial. Changing conditions compel re-
adjustments. Change is dangerous. Most important
results not always expected or desired. The conserva-
tive versus the radical.

•

•

•

•

•

XI. THE NATURE OF PROGRESS

Human nature the same in all ages. Progress de-

pends on intellectual development. Difficulty of main-

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353

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CHAPTER

taining high intellectual standards. The conception of

social evolution. The organic theory of society.

Spencer. The newer attitude of Sumner and Keller.

Social Darwinism.

Theories to account for the rise and downfall of great

civilizations. Exact answers cannot be given. Older
emphasis on personal virtues. Newer emphasis on
social virtues. Certain tests of fitness of a state to
survive. Selection of right crimes. The degree of
protection given the bodies and lives of citizens. The
education of children. The elimination of the unfit.
The ability to readjust to new conditions. Crystalliza-
tion of institutions. Neither race nor environment
alone account for civilization. The failure of panaceas.

INDEX

PAGE

397

Suggested explanation of color inheritance in guinea pigs. 204