472 The Journal 
the reaction, or behavior, is the resultant 
or product of the two. The great 
mistake that social agencies have made 
in the past is that they have over- 
looked the constitutional or hereditary 
factor of the reaction. The chief value 
of a detailed study of this sort lies in 
this: that it demonstrates again the 
importance of the factor of heredity.” 
A more detailed examination gives 
little encouragement to those social 
optimists who think that Nature cures 
such plagues as the Jukes by bringing 
them gradually to extinction. With 
the increase of charity, of baby-saving 
devices, and misguided philanthropy, 
bad breeding tends rather to increase. 
The average fecundity of the Juke 
women is stated to be 3.526 children or, 
if those who have no children are 
excluded, 4.025 per female. From 20 to 
30% of the births have been illegitimate. 
Of the 2,094 Jukes enumerated, 
1,258 are now living in this country. 
“Although many are old, the great 
majority are now in the prime of life 
and reproducing continually. The 
younger? generation is still in school. 
“The Jukes of today are to be found in 
all classes of society. The good citizen, 
prosperous and rearing a family with 
good moral and mental stamina, has 
earned his place in the community. 
Then there is the more numerous class, 
composed of steady, hard-working per- 
sons who toil from day to day at semi- 
skilled or unskilled labor and make 
no deep impression on the community, 
but rear their children as well as their 
limited outlook on the world will allow, 
endeavoring at least to raise them to 
the parental social level. Again, there 
is the scum of society represented 
among the Jukes. These are inefficient 
and indolent, unwilling or unable to 
take advantage of any opportunity 
which offers itself or is offered to them. 
These form the real social problem of the 
Jukes today. 
SOME USEFUL JUKES 
“An attempt has been made to classify 
the living Jukes into these three classes. 
5 This evidently refers to the eighth generation, 
two individuals. 
of Heredity 
There are 748 Jukes over the age of 15 
considered in this connection. There 
are, roughly speaking, seventy-six in 
the first class, the socially adequate; 
255 individuals are doing fairly well; 
323 are typical Jukes of the kind 
described by Dugdale, and ninety-four 
were unclassified, due to lack of suffi- 
cient information. The writer realizes 
that these figures mean little except 
to give a comparative idea of the 
general proportion of the three classes. 
As time goes on many of the younger 
ones classed as ‘doing poorly’ may, 
through added responsibility and as 
the result of experience, enter the 
second or even the first class. Those 
who remain, not profiting by experience, 
are the mentally deficient, for whom 
nothing can be done except to give 
continual oversight or custodial care.” 
Consanguineous marriage in the group 
is studied with care and the inference 
drawn “that cousin marriage in the 
lines where there is mental defect tends 
to reproduce that defect and intensify 
it; but when there is mental and moral 
strength in certain characters on both 
sides there may, in certain matings, 
arise offspring who are superior to 
either parent.” The inheritance of 
eroticism and pauperism are similarly 
studied, but the results are hardly con- 
clusive, in view of the difficulty of 
defining such traits and of separating 
out the environmental influences. Crim- 
inality is believed to be largely feeble- 
mindedness. 
It was not to be expected that this 
study would throw much light on the 
heredity of specific traits, for it was 
not undertaken with that view, but 
with a view to determine the effect of 
a changed environment. Estabrook 
divides his treatment of the latter 
subject into “involuntary removals” 
and ‘‘voluntary removals.” In describ- 
ing the latter, he seems to overlook the 
fact that those who migrate voluntarily 
are likely to be superior to the average, 
or they would not have sufficient enter- 
prise to migrate. A fairer test of 
environmental influence is involuntary 
The ninth generation so far includes only 
