490 
ANTHROPOLOGY: F. BOAS 
Proc. N. a. S. 
much slighter for earher years, but no material is available relating to this 
question. A more detailed study of the relation between increment and 
stature shows that the increment cannot be represented as proportional 
to the deviation of stature from the norm, but that a more complex rela- 
tion prevails. This is evidently due to the fact that at a given age there 
are, among short individuals, a considerable number who are retarded in 
development and that the number of those retarded decreases rapidly with 
the increase of stature so that among tall children of a given age those of 
accelerated development prevail. Since the increments of stature from 
ten years on to the adult stage cannot be expressed by a linear equation 
dependent upon age, it follows that the correlation between increment 
and adult stature as dependent upon initial stature can also not be ex- 
pressed by a linear equation. 
In other words we have to consider two factors. On the one hand 
there is the effect of retardation and acceleration which is most prominent 
in children of low and of high statures respectively and which results in a 
high increment for short children and a low increment for tall children and 
on the other hand there is the effect of hereditary stature which results in a 
low increment for short children of normal rate of development and in a 
high increment for tall children of normal rate of development. 
It would be unreasonable to assume that among individuals who by 
heredity would grow to be tall, there should be a few only who would be 
retarded; since the causes of retardation are present in the whole socially 
uniform group which has been studied. The children are all children of 
well-to-do parents, well-nourished and living in a fairly open country, 
attending a school in which their health is carefully looked after. The 
retardation must, therefore, be due partly to an hereditary determination 
of the period of development; partly to individual pathological or semi- 
pathological conditions, which are not likely to be dependent upon 
hereditary stature. If then we find that those individuals who are short 
as adults, show from 11 and 12 years on a considerable degree of retarda- 
tion, this can only be explained by the fact that the retardation has a 
permanent effect upon the development of the bulk of the body. Con- 
sidering these conditions we must conclude that the loss of stature due to 
retardation in early childhood is not made up during the period of adoles- 
cence. In other words, that the ultimate stature is an effect of both 
hereditary and environmental causes. 
I have investigated the same question with a different kind of material. 
I had an opportunity to examine a large series of Jewish children in New 
York City, living under different conditions. One group were students 
in a private school, the children of well to do parents; the second lived 
under normal family conditions on the East Side of New York City; the 
third group were boarded children under the care of charity organizations ; 
the fourth group were placed in an educational institution in the open 
