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VOLUME 24 NOVEMBER 1959 NUMBER 5, PART I
ARTICLES
THE
SEARCH
FOR
KNOWLEDGE
OF THE
CHILD
AND
THE
SIGNIFICANCE
OF
HIS
GROWTH
AND
DEVELOPMENT-EXAMPLES
FROM
THE HARVARD
LONGI-TUDINAL
STUDIES
Borden
Award
Address*
Harold C. Stuart, M.D.
I)cpartment of Maternal and Child Health, Harvard School of Public Health
INTRODUCTORY REMARKS
First, I wish to express m deep :tp1ec’iati11 for the Borden Award of the American Acadeniv
of Pediatrics and the recognition vhich it con\’evS, not univ for my studies over the past :30 ‘ears
but for the vork of m associates who have contributed to them in man ways.
Before (liscussing tliC stli(liCs for which I have bceii responsible I vish to e11)haSiZe that
search for knowledge of the child has 1)een uII(lertaken l niany people at (lifferent 1)eriodS in
fllaIIV l)laces and that pioneering Ill this l)artictllar field was underway in several I)laceS before
I l)ecame interested in it. Also, several groups have been pioneering concurrentJ’ with us in the
san-ic o’ closel related fields, The Academy has already conferred a Borden Award Ofl
Wash-1)nrn, vh() has 1)(’(I’l conducting most extensive longitudinal studies of children. That project and
till’ one at the Fels Foundation, Antioch College, Ohio, under the direction of Sontag, were
Starte(1 at about the sanie time and are still continuing and expanding under the original
(lireC-tion. Time does not I)ermit even naming the other projects which have been in operation over
recent ears in this and related fields.
During the first t\VO (lecadeS or more of the present centur various cross-sectional studies
were niaie and norms were developed to describe )OpulatiOfls of children b age, supposed1
to l’lp to (listinguish the al)norl1al from tI’ normal child. The concept gradually emerged.
however, that to fully un(lerstan(1 tlIC significalice of a child’s developmental status it was
neces-sarv to fo1lo his progress p(rt(1i(’a1ly alid to obtain concurrently information as to the major
features of his life experiences.
I had the good fortune in 1928-1 929 through two chance occurrences to be brought into this
field of inqUiry and to have close contacts with several leaders in it. First, I was asked to accept,
in addition to my clinical work and teaching in Pediatrics at the Harvard Medical School,
re-sponsibi!itv for developing teaching and reSL’arc’h in Child Hygiene at the Harvard School of
This address contains a helpful guide to the practical use and significance of the material presented
iii the SUPPLEMENT to this iSsue of PEDIATRICs-Editor.
Presented at the Annual Meeting of the American Academy of Pediatrics on October 5, 1959.
ADDRESS: 55 Shattuck Street, Boston 15, Massachusetts.
IEDIATRICS, November 1959
Public Health. The reason, I suspect, was that as head of the medical out-patient department at
the Children’s Hospital I had organized an appointment system in the hope not only of
provid-ing greater continuity in medical care but also for study of the progress of growth and
develop-ment in health as well as in illness. I accepted the proposal with enthusiasm because it afforded
an opportunity to go forward in a direction which already had aroused my interest. It required
that I give more thought to the community health problems of children and to community
services to deal with them, but I appreciated fully that the success of any community health
program for children must be judged by the adequacy of the care rendered to individual
chil-dren and that this in turn depended in large measure upon knowledge of health and
develop-ment of children and the individuality of their basic needs. It was clear that knowledge of growth and development, of what constitutes health for the individual child and what factors
determine his individual needs was very inadequate.
A second opportunity was presented to me a few months later by Kenneth Blackfan, then
Professor of Pediatrics at the Harvard Medical School. He had just been appointed Chairman
of a Committee on Growth and Development to prepare reports for the forthcoming White
House Conference of 1930 on “Child Health and Protection” and he asked me to serve as
As-sistant Chairman of his Committee. In this connection I had the stimulating and educational
experience of frequent contacts with leaders in several basic sciences, as well as clinical fields,
who had made important contributions to knowledge of growth and development. The repors
from this Conference prepared by its several committees were valuable compilations of the
knowledge of the child then available but were filled with references to the great need for
further knowledge. The Longitudinal Studies at the Harvard School of Public Health, therefore,
stemme(l in part from m new responsibilities at that School and in part from my experiences in connection with the White House Conference of 1930.
THE CHARACTERISTICS
OF THE HARVARD
LONGITUDINAL
STUDIES
T
HE TERM “pioneering studies” is a real-istic one and accounts for some of ourfailures. It implies starting toward given
goals, following attractive leads, which in
some instances proved unrewarding, and
making changes in method or direction of progress. Much time and effort were
ex-pended at every stage of this research to learn what kinds of information of the types desired could he obtained with sufficient
reliability and what were the most
perti-nent items to retain when the total observa-tions proved excessive. Many changes in
procedure with age of child were impera-tive and when the first children reached adolescence the staff was still pioneering in the attempt to learn how to obtain the
information then required.
A collateral purpose of this research was
to secure individual case histories of
longi-tudinal character and with the clinical
at-mosphere suitable for teaching growth and development. I believed that having this
project centered in a pediatric teaching
hospital contributed toward broadening the interest of many young pediatricians in
the health and development of essentially
normal children. Having well documented
longitudinal records of individual children has been found to provide excellent
op-portunities for case studies of health and development by students or for discussion
at teaching conferences.
Clinical studies of pregnant women were
started as early as possible in pregnancy at the Boston Lying-in Hospital and the first examinations of their infants were carried
out soon after birth and again before dis-charge. With few exceptions, subsequent
examinations were carried out by a multi-disciplinary staff at a special clinic adjacent to the Children’s Hospital. The first infants were enrolled in 1930 and the final
ex-amination on the last individuals to reah
their eighteenth year were completed at the
end of 1956. A small staff is now occupied
in analyzing the large accumulations of
data and in preparing reports.
The reports in the current series deal
pre-natal period to their eighteenth year,
re-ferred to as the Maturity Series. This
con-sists of 134 children, 67 girls and 67 boys.
Five papers constitute a Supplement to this
issue of PEDIATRICS. The first of these
out-lines the development and content of this
research and describes a bibliography of 52
previous publications based upon or
relat-ing to it. The following four papers
de-scribe the several patterns of progress
fol-lowed by the children in the Maturity
Series in skeletal age (hand), growth in
height
and in weight, total dietary intakesof protein and calories, and total illness
ex-periences. The titles in themselves give
some notion of the major fields of
investiga-tiOfl. These require no further description
as they are now available to the reader.
A second Supplement is being planned
for PEDIAmIcs which is so closely related to
the first that I regret the need for
consider-able delay before it will appear. This is to
include various studies of interrelationships,
based principally on the patterns described
in the present Supplement. Statistical
studies are being made by Dr. Robert Reed
of relationships by age periods between the
children’s patterns in the different fields.#{176}
APPLICATION
OF
PATtERN
CONCEPTS
TO
THE
EVALUATION
OF
HEALTH
AND
DEVELOPMENT
My purpose at this time is to suggest
cer-tain practical applications of the findings
respecting patterns as revealed in the
pres-cut series of reports. One objective of this
#{176}Dr. Reed is the statistician and co-director of
this research and is assisted by Miss Joan Cornoni.
Professor Bertha Burke, who has been in charge
of the dietary studies from the beginning, is
con-tinuing the analyses of the levels of nutrient in-takes. Dr. Idell Pyle, who has made all the
evalua-tions of radiographs, is continuing to assist in the
preparation of reports based upon them. Dr.
Isa-l)elle Valadian served for a time as pediatric as-sistant during the late years of data collection. She
has since made the analyses of the illness
experi-ences of these children and is continuing to work
on this aspect. Others who have worked in the
past on these studies or contributed to the
prepara-tion of reports are referred to in the appropriate
papers of the accompanying Supplement.
research from the beginning has been to
learn to what extent children differ or show similarities in their growth and develop-ment, in the amounts of nutrients they de-rive from foods ingested and in the number
and types of their illness experiences year by year. A second objective has been to learn how consistent individual children are in following the patterns to which they have usually conformed during each age period, that is, how steadily they maintain
their usual rate or level of progress. The
comments which follow relate to these two objectives.
A striking feature of the longitudinal
study of any aspect of children’s progress
is the variety of patterns which emerge. I
have selected for brief discussion, as one
example of this phenomenon, the patterns
of growth in height reported more fully in the third paper of the accompanying
Sup-plement. Two charts
(
Figs. 1 and 2) are presented to assist in this discussion. The growth of each child has been classified as“rapid,” “moderate” or “slow” during each of three broad age-intervals (up to 6 years, from 6 to 12 years and from 12 to 18
years). Those classified as “rapid” were
among the 25% of children showing most growth in height during the specified age period. Those classified as “moderate” were in the middle 50% of the group and those in the “slow” category were in the 25% with
least growth. As an example, a particular individual might be among the “rapid”
25% of children up to 6 years, among the
“slow” 25% from 6 to 12 years and then
grow at a “moderate” rate from 12 to 18
years. In this case his pattern would be
identified as RSM (Rapid-Slow-Moderate).
Using this system of classification 27 dif-ferent patterns exist as logical possibilities. Representatives of 19 of these patterns
were found among the 67 boys and 17
among the 67 girls. Although it is difficult and unwise to generalize in the presence of so much individual variability, certain of
these patterns appear more commonly and seem to be more characteristic of human
BOYS
50
-CM
‘00
50
0
RATE OF GROWTH
#{149}uo*t6
‘
6‘o 2 ,rJ
2‘o 8CASE
NO.
300
67
236
82
06
- RAPID
MoDiDwit
Mootw*rt
SLow
Slow
RAPID
RAPID
MootwAit
MOODNATI
SLOW
I I I I
SLOW
Si.ow
MoDtwaTt
RAPID
MoDtNaTt
6 12 18
AGE YR.
FIG. 1. Case examples of the five most commonly occurring pat-terns of growth in height for boys, classified according to rates of
growth during each of three age periods. Rapid represents upper
25%; Moderate, middle 5O; and Slow, lower 25%. Unbroken lines
give mean values and plus and minus one standard deviation at
successive ages.
Figure 1 presents single case examples of
each of the five most frequent patterns for
boys. In all of these patterns, except MMM,
there were more than twice the expected number of children. The mean values and
standard deviation for this group of boys is shown. It is thus possible to compare the curve for each boy with these norms for our group. This shows, for example, how ex-treme in respect to the standard deviation values were cases 300 and 106 at all ages,
and yet how consistently each boy followed
his own intrinsic pattern. None of the cases plotted follow a standard deviation line
closely throughout, although Case 182 is al-most always between the mean and minus
one sigma and Case 67 between the mean and plus one sigma. These deviate prin-cipally for a short period during
adoles-cence.
Figure 2 shows the same type of patterns for girls, except that Girl 181 is “slow” in rate in the middle period whereas Boy 182 was then “moderate” in rate. Pattern SSM for girls only occurred twice as often as
ex-pected, but the other patterns (as with
boys) occurred with greater frequency. The
norms are not plotted in Figure 2 in order
to permit clearer recognition of the
age-period changes in certain patterns.
The purpose in presenting these two
CM /////*/
//
,,,,CASE [_ OF GROWTH
/.c 110 6 6OI2
261 RAPID RAPID SLOW
296 --- MODERATE RAPID SLOW
292 MODERATE MODERATE MODERATE
SI Slow SLow RAPID
29 -
----
SLOW SLOW MOOtNAI I
-0 6
AGE YR. 2 8
FIG. 2. Case examples for girls as in Figure 1, except that norms
for girls are not plotted to permit clearer recognition of individual
pattern differences.
ARTICLES 705
200 -T 1 1
GIRLS
I I I 1
-
f I Iexamples of differences which commonly
occur among children of each sex in their basic patterns of growth in height. A
com-pai’ison of the curves of Girls 181 and 29 is
of interest in respect to predictability and
the possible interpretation of the
differ-ences between them. In the first period,
that is, up to 6 years, these two girls were
almost indistinguishable, whereas thereafter
they deviated sharply. Although both
con-tinued to progress slowly during the middle
period in respect to the norms, in accord-ance with the chosen method of
classifica-tion, Girl 29 clearly progressed more slowly
than did Girl 181. Also, in the third period
both increased their rates of progress, Girl
181 changing to “rapid” but Girl 29 only
to “moderate” in rate. As to predictability
at age 6 years, one could not have
distin-guished between these girls on the basis of height alone, the expectancy being that both would remain somewhat short. By 12
years of age a difference between them at
maturity would have seemed probable but
not to the extent ultimately occurring, be-cause the change from “slow” to “rapid”
on the part of Girl 181 could not have been anticipated.
The explanation for Girl 29 becoming so very slow in the middle period might be
entirely on the basis of intrinsic pattern,
but it could be postulated that a child with a feeble growth potential had been further
slowed in growth during this period by nutritional or other factors. A detailed study of all interrelationships may throw light
on this but the evenness of progress from
factor dU(l iIl(licat(’ (‘itIli’r t long ca)Iltinhling
health factor, a basic individual
characteris-tic or a combination of the two. This girl
did not reach menarche until 132 years
which correlates vell with her rather late
increased rate of growth associated with
adolescence.
In comparing the curves for boys with
those for girls in Figures 1 and 2 similarities
ill the case examples are evident. Boy 2.36 1I1(I Girl 292 are seen to he
middle-of-the-roa(l indivi(luals, growing more or less like
the average child. At the tipper extreme
Boy 300 tI1(l Girl 261 grew more rapidly
than niost children during their early years
and I)V continuing vigorous growth
re-mained tall for age throughout childhood. Ifl contrast to these, Boy 106 and Girl 29
cOITIl)ined relatively slow growth in the
early years vith a late and relatively weak
adolescent growth. The remaining four
in-(livicluals achieved average adult height by
t\V()
(mite
different routes. Boy 67 andGirl 296 showed moderate growth in the earls’ years followed iy early and vigorous
adolescent growth which caused them
temporarily, I)ut onh’ temporarily, to forge
ahead of the middle-of-the-road children.
Boy 182 and Girl 181 grew slowly during
the early years but managed to achieve an
average mature height by late but vigorous
adolescent growth.
The Pttterns I)ortrtYe(1 in the two
Fig-tires indicate how difficult and hazardous it
is to Predict ultimate height during middle
childhood, as hoped for by the parents of
very tall girls or short boys in this period.
Two common patterns that are presented
result in radical change during adolescence,
so that ultimate height is much closer to the
average than would otherwise have been
anticipated. Two other patterns, in contrast,
maintain the early differences in height at maturity. Periodic measurements usually
reveal at or about puberty the pattern to be
followed thereafter and an earlier
radio-graph of the hand may aid in this
irelic-tion. Our interest here, however, is rather in
the recognition of what is appropriate for
the ill(hivi(lual and thus to he aware of
de-viations from individual pattern which may
he the result of unsatisfactory health or
one or more environmental factors.
In considering the consistency of a child’s
progress at any period it is imperative to
do so in respect to some standard of refer-ence. It must be appreciated that norms which give means and standard deviations
Oi percentiles by sex and age throughout
total childhoods provide a composite
pie-ture only of all children in the group
uti-lized. \Vhen comparing individual children
with any such norm it is obvious that those
who characteristically and appropriately
change their rate of progress at one period
from that of the preceding one will appear
to be inconsistent in progress at that time.
However, if different patterns of progress are identified, as in the charts presented, and the pattern to which a given child con-forms is recognized he may be found con-sistent for children of his type. From this standpoint a study of the papers in the
accompanying Supplement will show how radically different children may be in their patterns of progress and still remain con-sistent for themselves in respect to their
own unique pattern. Also, some are always
much like themselves in the characteristics
of their progress while others show a
marked degree of variability (luring one or
more age periods.
Irregularities in measurable gains are
common for all measurements at all ages.
They are particularly common in the first
3 to 6 months of life in respect to height
and weight and in the evidences of skeletal
maturation. They tend to be greater for small measurements than for large, due in
part to the unavoidable minor errors
in-volved in measuring children. It is also
probable that there are minor fluctuations
in the rate of growth itself, and this would
be expected to be greater during the early
months of life when lability or variability is
commonly associated with the lack of
sta-bilization of physiologic processes. Because
ARTICLES 707
year of life, one must be cautious in trying
to identify the pattern of a child’s growth on
the basis of progress during the early months at least.
Irregularities in the curves of plotted
weight measurements are usually greater
than those for height because body weight is
determined both by growth and by losses or
gains in the storage of fat and water in the
tissues. However, weight curves based on
3, 6 or 12-month determinations are
corn-rnonly very smooth and reveal patterns
which
are characteristic of groups ofchil-dren. When viewed in relation to the
pat-terns for height, they frequently reveal the
age of onset and natural course of a cycle of
obesity superimposed upon that of normal
growth. They may also reveal failure to
gain in accordance with the latter.
The patterns of skeletal maturation in the
hand, derived from assessments by Pyle
and described in the second paper in the
Supplement, show great variety, as with
body measurements. They also show
strik-ing individual consistency within a given
pattern though occasionally sharp deviations
are encountered. The close associations be-tween patterns of change at puberty in
skeletal age (hand) and growth in height
have been reported by numerous observers
and have -been noted repeatedly in our case
stu(lieS.
The fourth paper in the Supplement
re-ports patterns of total intake of protein
and calories year by year throughout
in-dividual childhoods and the fifth paper
re-ports patterns of total illnesses and total
scores for illnesses; these papers probably represent the most unique sets of data emerging from these studies. The patterns
of intakes and of illness experiences are as
varied and show as radical changes
be-tween certain age-periods as do those for measurements of the body.
There are many children in the Maturity
Series who show marked variations from
the average in both the intakes of calories and protein and the rates of change in
in-takes from period to period. It is of
in-terest that some children, more or less
con-sistently over long periods, consume about
half the recommended dietary allowances for age, while others consume nearly twice
these amounts. The longitudinal patterns of
intakes shown in these papers allow study
of each child in this series in relation to
every other child for any given period of
time. Most importantly, the nutrient
in-takes over whole childhoods can be studied
in relationship to the manifestations of tile
health and development of these children.
The wide variations in intakes of either
calories or protein at any given age are such
that average values are useful only for
gen-eral orientation.
The 134 children in this group (Maturity
Series) were found to differ greatly in the total number of illnesses which they ex-perienced during the period from birth
to 18 years. The range was from 17 to 104,
with the majority of boys having between
36 and 70 and the girls, 20 to 36. This
ex-cess of illnesses for boys over girls was
characteristic of most ages but most
strik-ing for the Preschool and School periods.
Mild to moderate illnesses predominated
at all ages but the highest number an(l
greatest severity of illnesses for both sexes
occurred during the Preschool period. Tile
lowest number and severity occurred
dur-ing adolescence. These children were also
found to conform to a few characteristic patterns of changing numbers of illnesses
by age periods. Fourteen different patterns
were identified, based on similarities in
number and severity of total illnesses and
in the age period in which these
predomi-nated. These characteristics of individual
differences provide a frame of reference against which a given child’s record can
be compared, his future expectancies
tenta-tively assessed and his particular needs for
closer supervision recognized. It is worth noting that under the conditions of health services, generally the age of maximum ill-nesses is the period in which children are
most commonly lost sight of or are least
Vala-dian is now preparing a second paper
deal-ing with frequencies and seventies of ill-nesses at each age-period by types. This will add much useful information from
these studies and it is hoped will appear
shortly in an issue of PEDIATRICS.
In studying the papers in the present
Supplement, it would be well to note the
ages at which changes in rates or levels
are to be expected under the several
pat-terns. This will afford cities to the
recogni-tion of the appropriate one for any given child and the wide and quite normal de-viations which such individual differences
from population norms make mandatory for
them. With this approach it becomes
evi-dent that consistency in progress may be
viewed as an attribute of normal growth
and development only in respect to the
in-clividual chulds intrinsic pattern, hut not
necessarily in position with respect to
popu-lation norms. The significance of
irregulari-ties in progress over short periods, that is,
deviations from an’ recognized pattern,
cannot be discussed on the basis of our
studies until tile interrelationships
pre-viously referred to have been studied for
tile group, nor can the possible associations
between rate of growth or of skeletal
mat-tiration and dietary intakes or illnesses
ex-periences be reported.
In applying this concept of individual
differences in patterns of progress, one may
sum up with the following suggestions: 1)
Expect considerable variability in young
in-fants and therefore adopt the policy of
watchful waiting in expectation of
stabi-lization of physiologic processes and other
factors relating to growth. The word
“watchful” as used here calls for closer
at-tention to care and environmental circum-stances than might be given were there more consistent progress, but without any
immediate implication that the finding is
unsatisfactor. 2) At all ages watch for
consistent progress but do not expect this
to continue along a percentile or other
standard line of reference, that is,
appreci-ate that normal progress for the individual
niay be fast, moderate or slow in relation to group norms. If this be the case, certain
deviations from a group norm are to be
ex-pected. 3) When the rate of progress
changes as, for example, in Figure 2, Case
29, at 6 years, note it and investigate for
possible cause as suggested above for in-fancy; however, keep in mind the possibility
that this is a change reflecting intrinsic
pat-tern. If the latter be so, progress following
the change would -be expected to become
consistent at the altered rate. Remember
that changes occur toward a more rapid
rate as well as toward a less rapid one. In respect to the cure for body weight, at
least, this may have as much importance as
a change toward a slower rate of gain. 4)
Keep in mind that quite radical changes
in rate of growth commonly occur in asso-ciation with pubescent changes.
Recogni-tion of this may greatly improve the
ac-curacy of prediction as to an individual’s
probable ultimate stature.
SUGGESTIONS
AS TO PROMISING
LONGITUDINAL
STUDIES IN THE
YEARS IMMEDIATELY
AHEAD
With few exceptions longitudinal studies
need not cover whole childhoods. There are many compelling reasons for shortening the
spans of observations, which I cannot
re-view here. Enrolling groups of children of
different ages for shorter periods of
ob-servation, with careful planning for over-lapping ages, may compensate for many of the obvious disadvantages of having differ-ent children studied at each succeeding age. Short-term observations of the same children are far preferable to
cross-sec-tional observations of different individuals
at successive ages, particularly if one is
in-terested in learning the variety of responses manifest by children to chronic illnesses or
unfavorable environments. In setting up re-search in this way, however, one must
recognize the impossibility of comparing individuals with themselves at widely
ARTICLES 709
comparisons iLI& iit’Ccssaiv, at least for recognizing the overall effects of intrinsic
factors on total development of individuals.
It would be advantageous, therefore, to
have a few children observed from one
1)eriod to another at centers where
differ-(‘lit groups are under observation.
‘o-Iaily o)portunities present themselves
today in various parts of the world to study
tile effects of nutritional deficiencies,
chronic infections, parasitic infestations and
other types of diseases upon growth and
development at succeeding age periods.
These opportunities must be taken
advan-tage of if we are to acquire an adequate
understanding of the long-time effects of
these conditions on the growth and devel-opment of children. They are particularly
necessary to gain knowledge of the
capaci-ties of children at different ages to make
adequate adaptations to tile impacts of
un-favorable climatic, dietary, social or
cul-tural circumstances. To make such studies
effective it would be imperative to have
well coordinated projects developed on an
international basis in order to provide for
comparisons of adequate samples of
chil-dren living under vastly different
circum-stances. They would have to be coordinated
under agreements as to technical
proced-ures to be adoptedi in common. For this
reason, I am troubled by the continuing
evidence of individualism in the planning
of growth studies. it is appropriate that in
early phases much time should be spent on developing better techniques for obtaining
and recording data. However, all interested
persons should weigh carefully the advan-tages of using their preferred techniques as
against adopting a widely used, better understood or more readily applied method. It is often possible to resolve this kind of difficulty by having all agree to use one technique for comparative purposes, while
some continue a second for their own pur-poses, as for example, using both
recum-bent length and standing height for young children.
Although it is difficult to be entirely
op-timistic about early accomplishment of
truly international studies such as are
pro-posed, the attempt is being made in some
places, should be encouraged, and can be
successfully carried out. Tile Children’s
In-ternational Center in Paris has made com-mendable progress in this respect and should receive more encouragement from this Coun-try. Under the leadership of Dr. Berthet, this
Center already has affiliations with studies
under way in Paris, London, Brussels, Stock-holm, Zurich, Dakar, Kampala and Louis-ville. However, more goal-oriented studies
in selected countries will be required before
the interrelationships between the circum-stances of life and the progress of develop-ment can be adequately demonstrated.
The
American
Academy
of
Pediatrics
SPRING SESSION TWENTY-NINTH ANNUAL
MEETING
April 20 to 22, 1960 October 17 to 20, 1960
Chalfonte-Haddon Hall Palmer House
