NEO-DARWINIAN SOCIOLOGISTS 95 
medical inspection in schools both in England and America as to 
be of negative value. 
Other of the studies are of far greater value, as those concerning 
the influence of alcohol on heredity ! but even these are not con- 
clusive, except as indicating with a good degree of certainty that 
chronic alcoholism is more or less a symptom of germinal defect. 
The general conclusion of all the laboratory investigations is to 
the effect that mental and moral traits, as well as physical, includ- 
ing insane and tubercular diathesis, are inheritable in about the 
same ratio,’ and that heredity is vastly more important than 
environment. The writer goes so far, even, as to hold that 
medical progress, by suspending the operation of natural selection 
by prolonging the lives of those who otherwise would have been 
“ selected,” has weakened the average quality of the race-stock,® 
and that this tendency can be counteracted only by national 
eugenics. 
Mr. Galton wrote his Hereditary Genius from the point of view 
of Darwin’s theories of natural selection, pangenesis and the 
inheritance of acquired characters, but later accepted the teach- 
ings of Weismann. Pearson, in his Grammar of Science, makes 
room for other factors in race-stock improvement besides natural 
selection,’ but in his more recent writings he, too, has become a 
1 Memoirs, nos. x and xiii. 
* For sane criticism see Charity Organization Review, September, 1910. 
3 Lecture Series, no. ii, p. 20. How a moral trait can be inherited is not made 
clear. There is a strong tendency in modern psychology and ethics to repudiate 
the old teaching concerning a “ moral sense.” Biology has not yet revealed the 
possibility of inheriting anything that cannot be reduced to terms of the physical 
(including the nervous system). If there be innate moral traits they must be a 
function of the nervous system. The nearest approach that modern psychology 
can make is in its assumption of a gregarious or social instinct, and possibly of an 
instinct that leads one to do as others do. Recent studies of juvenile delinquency 
have failed to find any specific inheritance of criminal tendencies, and criminal 
psychologists are now questioning the existence of the class of so-called “ moral 
delinquents.” Cf. Healey, The Individual Delinquent. 
4 “ We find that the effect of nurture is on the average hardly one-fifth to one- 
tenth that of heredity.” — Lecture Series, no. vii, p. 7. Yet in no case has the 
factor of heredity been kept entirely separate from early home training except in 
Galton’s study of twins. Cf. Ward’s Applied Sociology. 
5 Lecture Series, no. ix, p. 19. 
® Grammar of Science, p. 378. Cf. concluding chapter of this volume. 
