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Boas, Franz. Race, Language and Culture – T09


Remarks on the anthropological
study of children 11

If I venture to lay before you some brief remarks on the anthropological
study of children, I do so for the reason that problems of
hygiene are necessarily based on the consideration of the anatomical,
physiological, and pathological conditions of masses of individuals,
phenomena with which anthropological science is intimately concerned,
for anthropology deals with the racial and social influences that determine
form and function of the body, without reference to the peculiarities
of the individual as such, although the range of variations in form
and function in individuals who constitute a social group is a most important
topic of our investigations. I wish to deprecate, therefore, at the
outset all attempts at an individualistic interpretation of our results,
which express only the general conditions that have to be considered in
a study of the life of the individual, and which are modified in each
individual by his peculiar life history and hereditary conditions that
cannot be expressed in our generalized results. Nevertheless, the importance
of these is great, for they express in a concise way the general
effects of social and racial conditions that cannot be formulated in any
other manner, and set definite problems to the student of hygiene as
well as of anatomy and physiology.

The phenomena that interest us here are those of the development
and growth of the child. The first attempt to study growth by metrical
methods was made by Quetelet, in Belgium; but our first accurate
knowledge is due to the investigations of Henry P. Bowditch, in Boston,
and, later on, to those of Roberts, in England. These were followed by
work on similar lines in America, Italy, Germany, France, Russia, and
Japan. New lines of research were developed by the application of more
rigid biometrical methods, the development of which we owe in large
part to the influence of Francis Galton and to the work of Karl Pearson.94

The results of these studies and the present status of the problem may
be summarized as follows: The rate of growth of the body, measured
by weight and stature, increases very rapidly until the fifth month of
fetal life. From that time on the rate of growth decreases, first rapidly,
then more slowly, until about four years before the age of puberty.
During adolescence the rate of growth is considerably accelerated, and
decreases again rapidly after sexual maturity has been reached. Thus
the curve of growth represents a line which possesses a very high maximum
at about the fifth month of fetal life. It decreases rapidly, and
has a second although much lower maximum shortly before sexual
maturity is reached, and not long afterwards reaches the zero point.
The increase in bulk of the body continues much longer than that of
length. In the beginning the rates of growth of the two sexes are about
equal, that of the male probably exceeding slightly that of the female.
Since, however, sexual maturity begins to develop earlier in the female
than in the male, the concomitant acceleration also sets in at an earlier
time, with the result that for a few years girls have a larger bulk of body
than boys.

Although the periods of most active growth of the parts of the body
differ considerably, it would seem that the characteristics of the curve
of growth as here outlined are repeated in many if not in all organs and
parts of the body. For instance, although the head reaches nearly its
full size at an early time, so that its rate of growth shows a much more
rapid decrease with age than that of the bulk of the body, there is an
acceleration of growth during the period of adolescence. The differences
between the sexes are in this case quite marked in early life, the
head of the girl being always considerably smaller than that of the boy.
The early prepubertal acceleration of the girl is not sufficient to bring
the head measurements of girls up to those of boys, even during the
prepubertal period. The difference in the measurement of the sexes is,
therefore, not by any means solely due to the shorter period of development
of girls, as might be supposed from a study of stature and weight
alone, but important secondary sexual characteristics exist in early

These prove that the difference in physiological development between
the two sexes begins at a very early time, and that in the
fifth year it has already reached a value of more than a year and a

I give here a tabular statement of the available observations:95

tableau Age in years | Difference | Boys | Girls | Ossification of scaphoid | Ossification of trapezoid | Eruption of inner permanent incisors | Eruption of outer permanent incisors | Eruption of bicuspids | Minimum increase of annual growth | Eruption of canines | Maximum increase of annual growth | Eruption of second molars | Maximum variability of stature

These data are not very accurate and must be considered a first approximation

When we remember that growth depends upon physiological development,
it will be recognized that we must not compare the stature of
girls of a certain age with that of boys of the same age, but that from
the fourth year on a girl of a certain age should be compared with a
boy a year and a half older than she is.

If this view is correct, then it appears that the relation in size of the
two sexes persists even in childhood.

I think no better proof can be given of the correctness of this view
than the peculiar behavior of those parts of the body which complete
their growth at a very early time; for instance, that of the head. 12 The
total amount of the growth of the head from the second year on is
slight. If, therefore, girls are ahead of boys in their development by
about a year and a half or two years, the total amount of growth of the
head in their favor will be the small amount of growth accomplished
during this period of a year and a half or two years. If, then, there is
a typical difference between the size of the body of male and female
in childhood of the same character as found in adult life, then the head
of the girl ought to be at all periods smaller than the head of the boy;
and this is what actually happens. The phenomenon has been interpreted
as indicating a less favorable development of the head of the
woman ; but the previous remarks show that it is obviously due solely to
the different rate of physiological development of the two sexes. The
results of physiological tests which show very generally that girls do
better than boys of the same age may be another expression of the
general acceleration of their development.96

While we may thus speak of a curve of growth and development of
the whole body and its organs, which has characteristic values for each
moment in the life of the totality of individuals that compose a social
group, not all the individuals pass through these stages of development
with equal rapidity. It is easiest to make these conditions clear to ourselves
by stating the various ages at which certain points in the physiological
development of the individual are reached. Data are available
for the periods of pregnancy, eruption of teeth, pubescence, sexual
maturity, and development of long bones. So far as these can be reduced
according to fairly accurate methods, the following results have
been obtained: The average period of pregnancy is 269.4 days. One-fourth
of all the children observed have been born in the periods of
pregnancy between 265 and 273 days, one-half, between 260 and 278
days, and three-fourths, between 254 and 285 days. According to the
laws of large numbers, the ratio of children born between any other
limits of time can be determined, if any one of the pairs of values here
mentioned is known; for instance, the pair which indicates the limits
in which the middle half of all the children are born. In our case these
limits are, accurately speaking, 269.4 days (the average), plus and
minus 9 days. We may, therefore, call 9 days the measure of the
variability of the period of pregnancy. I repeat that this means that
one-half of all the children are born within the period limited by 269.4
days (the average), minus 9 days (i.e., 260.4 days), and plus 9 days
(i.e., 278.4 days). In this way the variabilities shown in table on page
98 13 have been determined.

It appears, from this table, which may be represented in the form
of a curve, that the variability of the physiological stages of development
increases very rapidly, probably so that its logarithm is in a ratio
approximately proportional to the actual age, or, to use the term applied
by Dr. Crampton and Dr. Rotch, to the chronological age. The causes
that lead to this rapidly increasing variability are so far entirely unknown.
It is certain, however, that there must be definite causes at
work which bring about this phenomenon; for, if the variability were
due to accidental causes only, it would increase much more slowly
than in a ratio proportional to the increasing age, namely, proportional
to its square root. The study of the general curve indicating the increase
of variability in physiological development points to an irregularity at97

tableau Age (years) | Variability (years) | Pregnancy | First incisors | First molars | Inner permanent incisors, girls | Inner permanent incisors, boys | Outer permanent incisors, girls | Bicuspids, girls | Outer permanent incisors, boys | Bicuspids, boys | Permanent canines, boys | Permanent canines, girls | Appearance of pubic hair, boys (Boas) | Second molars, girls | Second molars, boys | Appearance of pubic hair, boys (Crampton) | Full development of pubic hair, boys (Boas) | Full development of pubic hair, boys (Crampton) | Puberty, girls | Wisdom teeth, boys | Wisdom teeth, girls | Menopause | Death due to arterial diseases, men

the time of approaching maturity. At this period the variability seems
to increase at an unusually rapid rate, and either to be stationary or to
decrease again at a later time.

I have spoken here of the variability of the physiological development
of the body as though this were a unit. In 1895, in a discussion
of Porter's observations on the growth of school children in St. Louis,
I pointed out the fact that a general variability in physiological development
accounts for the close correlation between the distribution of children
of the same age in school grades and the variations in the size of
the body and its organs; and this problem was later on worked out by
myself and Dr. Clark Wissler in regard to various measurements. These
correlations have also been proved in a most interesting manner by Dr.
Crampton's observations on pubescence, and by Dr. Rotch's study of
the development of the epiphyses. It is true that a close correlation
between the states of the physiological development of the various parts
of the body exists, but there exists also a certain amount of variability
in the development of one organ when another one has reached a certain
definite stage. The correlation is so close that the condition of
the bones, or that of pubescence, gives us a better insight into the physiological
development of the individual than his actual chronological
98age, and may therefore be advantageously used for the regulation of
child labor and school entrance, as Dr. Rotch and Dr. Crampton
advocate; but we must not commit the error of identifying physiological
development with physiological age, or of considering chronological
age as irrelevant.

The clearest proof that is available is found in the data relating to
increase of stature, and in observations on pubescence made according
to Dr. Crampton's methods. Bowditch was the first to investigate the
phenomenon of growth of individuals who are short or tall at a given
age, but his method was based on a statistical error. Later on, I showed
that retarded individuals possess a late acceleration of growth, and these
results were amplified by studies made by Dr. Beyer and Dr. Wissler.
Recently I had occasion to make a more detailed statistical analysis of
the phenomenon of growth, 14 which shows that groups whose prepubertal
accelerated growth begins late in life have rates of growth that exceed
by far those of the normal individual; in other words, that, among the
retarded groups, the whole energy required for growth is expended in
a very brief period. In the case of stature, the phenomenon is complicated
by the great differences in hereditary stature among the various
parts of the population. It appears more clearly in observations on
pubescence. Thus it can be shown that, if the first pubic hair appears
in one group of boys at 11½ years, and in another at 15½ years, it will
take the former much longer than the latter to attain the full development
of pubic hair, and the rate of change found among them will be
much greater than that of normally developed individuals. In other
words, individuals who exhibit the same stages of physiological development
are not the same, physiologically speaking, if their actual chronological
ages differ; their past is not the same, and prospective physiological
changes in their bodies will proceed in different ways. It is clear,
therefore, that the greater the retardation or acceleration in any one
particular respect, the greater also will be the disharmonies that develop
in the body, since not all the other organs will follow the same rate of
acceleration and retardation. The causes of these phenomena are unknown,
but we may perhaps venture on the hypothetical explanation
that all the cells of the body undergo certain progressive changes with
increasing age, and that the internal secretions which become active
99at the time of puberty exert a stimulus upon the cells which causes accelerated
growth in the cells, which depends, however, also upon the
state of development of these cells. This may refer to the whole body,
as well as to the glands that have a direct influence upon the rate of
growth. In retarded individuals many of the cells have advanced in
their development more nearly normally than the groups of cells involved
in sexual maturity; and when their action sets in the cells of
the body are stimulated much more vigorously than the less developed
ones of an individual that reaches maturity at an earlier time. This
hypothesis, however, would have to be tested experimentally. It is intended
only to bring nearer to our understanding the complicated
phenomena of retarded and accelerated growth.

It seems very likely that the abnormally large amount of energy expended
upon rapid growth during a short period is an unfavorable
element in the individual development. A study of the phenomena of
growth of various groups of the same population has shown that early
development is a concomitant of economic well-being, and that for the
poor the general retardation in early childhood and the later accelerated
growth are characteristic. It follows from this that there is a corresponding,
although not equal, retardation in early mental development, and
a crowding of developmental processes later on that probably places a
considerable burden on the body and mind of the poor which the well
fed and cared for do not suffer. 15 The general laws of growth also show
that a retardation kept up for an unduly long period cannot be made
up in the short period of rapid growth; so that it would seem that, on
the whole, excessive retardation is an unfavorable element in the growth
and development of the individual. Whether there are similar disadvantages
in a considerable amount of early acceleration is not so clear.

A word may also be said in regard to the evident increase in the
general statures of the people of Europe, which has been proved by
the study of military statistics. I presume this is partly due to better
nutrition and earlier development, but it seems likely that much of it
may be due to the better control of infantile diseases, which exert a long
retarding influence upon the growth during the earlier years of childhood.

When we turn from the more general phenomena of growth to a
consideration of their controlling causes, particularly of the influences
100of heredity and of environment, we have to confess our ignorance of
the most elementary facts. While there is no doubt that the bodily size
of the parents determines to a certain extent the growth of the bulk of
the body of the children, it is not by any means clear in how far part
of this may be due to the controlling effect of environmental causes to
which parents and their children are equally subject. It is quite obvious
that the earlier in fetal life certain traits are formed, and the earlier they
reach their full development, the stronger will be the hereditary influence
; while the later in life the full development is attained the greater
will be the influence of environment, not only on account of the longer
time of its action but also owing to the greater diversity of its form.
Thus, if the anterior part of the palate has very nearly reached its final
form and size in the sixth year no amount of subsequent change of
food or use will materially influence its form; while weight and stature,
and, even more, mental development, will be modified by the influences
to which the individual is subject during the first two or three decades
of his life. The problem of growth must, therefore, be studied for
every organ independently.

Some observations have been made that illustrate the influence of
environment, not only upon growth of the bulk of the body but also
upon some of the forms that develop very early in life. Thus, it has
been shown that urban and rural populations in Europe exhibit characteristic
differences in size and form of the head. These differences
are slight, and the attempt has been made to explain them as due to
selection or mixture; but reasons can be brought forward that suggest
other causes for the modification of the bodily forms. It has also been
observed that a fairly homogeneous people like the East European Jews
develop distinctive forms in the different parts of Europe that they inhabit,
and that Italians, Bohemians, and Jews who come to America
develop distinctive characteristics. Whatever the causes of these changes
may be, whether due to selection or to internal changes brought about
by the new environment, they indicate that heredity is not the sole
factor that determines the development of the body.

The few observations which we possess on the growth of children of
different races seem to show that there are definite characteristics of the
growth curve for each group. Thus, Indian children seem to be shorter
than European children, while the adult Indian is as tall as or taller
than the European; but it is impossible to tell in how far this is due to
the mode of life and how far to the influences of heredity. It is not
101too much to say that all the work on these problems remains to be done.
Our ignorance of these facts should make us hesitate to judge rashly of
the mental and bodily inferiority or superiority of races, since the data
for forming a judgment are entirely lacking, and since most of the features
on which we are accustomed to form our judgment develop late
in life, and are therefore, as explained before, to a great extent subject
to the influence of environment.

Related to these questions is the problem of the period of development
of racial traits. At a very early stage of development children
of all races are much alike, and many of the most characteristic traits
do not develop until maturity is reached. Traces of these racial traits
may be observed at an early time, but their accentuation occurs comparatively
late. Here we have undoubtedly traits that are determined
by a long line of ancestors, not by environment. Thus, parts of the body
that are alike in childhood are subject to a more active growth in one
race than in another. For instance, the elevation of the nose of the
European, the prominence of the face of the Negro, the great length
of the leg of the Negro, the great width of face of the Mongol and
Indian are due to a marked growth of these features. Others, on the
other hand, lag behind. Thus we are confronted with the ontogenetic
problem of the origin of the diversity of human types, and of the oft-claimed
but never-proved phenomena of early arrest of development in
certain groups.

On the whole, what little we know would indicate that the periods
of growth are the same everywhere, but that the rate of growth of various
parts of the body is greater in one group than in another, and
that in this manner the racial characteristics are developed. Too little
is known, however, to express any definite opinion on this important

The subject is one that, in its general aspects, as well as in the questions
relating to the influence of heredity and environment, has a direct
bearing upon questions of social well-being and upon our estimate of
racial characteristics, and for this reason deserves systematic study, not
only for the sake of its scientific interest but also on account of its
practical importance.102

11 Transactions of the 15th International Congress on Hygiene and Demography,
held at Washington, D. C., September 23-28, 1912
, (Washington, 1913).

21 See also p. 114.

31 Compare table on p. 112 in which the ages and standard variabilities for other
features are given.

41 These observations, so far as stature is concerned, are contradicted by the data
given on p. 118. I have not had an opportunity to check the observations on
pubescence on new material.

51 This paragraph has to be revised in view of the contradictory observations
mentioned in note 1, p. 99, and the discussions of tempo of growth pp. 86 et seq.