PEDIATRICIANS' ASSESSMENTS OF THE INTELLIGENCE OF TWO-YEAR-OLDS AND THEIR MENTAL TEST SCORES

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PEDIATRICIANS’

ASSESSMENTS

OF

THE

INTELLIGENCE

OF

TWO-YEAR-OLDS

AND

THEIR

MENTAL

TEST SCORES

Jessie M. Bierman, M.D., M.S.P.H., Angie Connor, M.D., M.P.H.,

Marilyn Vaage, B.S., and Marjorie P. Honzik, Ph.D.

School of Public Health and Institute of Human Development, University of California,

Berkeley and Hawaii Department of Public Health

680

I

N MAKING his appraisal of a child’s

phys-ical development and health status, a

physician routinely takes into consideration the results of objective tests and

measure-ments of several kinds, but judgment about mental development is likely to be based on an informal combination of many kinds

of impressions and observations of the child’s behavior with little if any use of ob-jective measures.

In a recent article, Oppenheimer and

Kessler comment on the continuing dialogue

between pediatricians and psychologists

about the value of giving mental tests to young children.1 In their review, they cite

a number of historical developments and

research findings by both groups which

may have contributed to the expressed

dif-ferences of opinion. They point out that

there is among practitioners in the

child-care professions “either an attitude of total reverence for the IQ or an attitude of

skepticism.”

Psychologists experienced in testing

in-fants and young children have long urged

caution in the interpretation of test results, particularly in predicting intelligence in the individual child without observable

handi-23, 4 It is in connection with children

whom he suspects may be subnormal or who appear slow in development that the pediatrician has the greatest concern, and

it has been shown in test-retest studies that subnormal children show less shift in test scores than do those in the normal or

su-perior

6 7 Furthermore, it is

with this group that the pediatrician’s

“in-terpretive clinical judgment” and training are likely to have the most to contribute.

The purposes of the present study are (1) to explore the agreement between

pedi-atricians’ appraisals of intelligence and mental test scores of a group of two-year-olds in a clinic setting, (2) to identify some of the factors which appear to have influ-enced the differences, and (3) to show the

usefulness of test scores as a means of

as-sisting the pediatrician in his clinical

ap-praisals of young children who show

evi-dences of slow development.

SOURCE OF DATA AND MATERIALS

The data consist of the results of pediatric

and psychologic examinations given

rou-tinely in the second year of life to a cohort

of children included in the Kauai Pregnancy

Study.8 The major purpose of the examina-tions was to evaluate the outcomes of the

study pregnancies and to assess the extent

and nature of prenatal and perinatal

handi-capping.

The study group consists of 681

single-born full-term children resulting from a

(Submitted April 7; accepted for publication May 19, 1964.)

The Kauai Pregnancy Study was supported by grants from the Children’s Bureau and the Public

Health Service National Institutes of Health Grant No. 7734.

Dr. Bierman is Professor Emeritus and Director, and Mrs. Vaage, Statistician, Maternal and Child

Health Research Unit, School of Public Health, Berkeley; Dr. Connor is Executive Officer, Mental

Retardation Division, Hawaii Department of Health; and Dr. Honzik is Lecturer in Psychology and

Associate Research Psychologist, Institute of Human Development, University of California, Berkeley.

ADDRESS: (J.M.B.) Maternal and Child Health Research Unit, School of Public Health, 2288 Fulton Street, Room 302, Berkeley 4, California.

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00

BoysjIIl.Girls

(N:333) (N’348)

60

40

20

Low Normal Normal Superior

Pediatricians’ Assessments

time sample of all pregnancies on the Island

of Kauai, Hawaii, with last menstrual

pe-nod from the second lunar month of 1954 throtigh the third of 1955. Excluded were

31 prematures, because of the difficulty of

adjusting tile mental test scores for

pre-maturity; 83 not available for assessment,

primarily those who had moved; 6 who had

died; and 37 for whom one or both of the

assessments were not completed.

The diversity of ethnic groups which

make up Kauai’s population is reflected in

the

study group. Children of Japanese and

Filipino origin constitute over one-half,

part-Hawaiians are the next largest

seg-nient, and Caucasians, Puerto Ricans, other

Oriental groups and non-Hawaiian mixtures

make up the balance. The living standards,

health

status of the people, educational

level, availability and quality of medical

and health services compare favorably with

the

best mainland communities.9’ 1, 11

Pediatric Examination

Two

practicing pediatricians from

Hono-lulu, both Diplomates of the American

Board of Pediatrics, periodically came to

Kauai for a few days, and each examined

about half of the group. The median age at

examination vas 193 months with 95%

ex-amined l)cfore age 2. The principal focus of the examination was a search for birth

defects or deficits and an assessment of the

healtil status of each child. The children

were weighed and measurements taken of

their height and head and chest

circum-ference.

Each

of some 30 items was checked

“normal” or abnormal’ with space allowed for comments. These items covered a

sys-t(flIatiC appraisal of all organs. In addition,

nutrition, sleeping and feeding habits, toilet

training, speech, social and motor

develop-ment were appraised and the pediatrician

was asked to indicate his impression of the

child’s intellectual status by rating him as:

superior, normal, low normal, or retarded.

All of the pediatricians’ judgments were

1)asCd on the examination, observation of

the child’s behavior, and questioning of the

niotlier.

Pediatricians’ Assessments of Intelligence

Six hundred and thirty-six, or 93% of the

children were rated as normal (Fig. 1).

Only 8 children (1.2) were rated as

su-perior, 4.8% as low normal, and 0.6% as

re-tarded. Thus, of the total 681, only 1 girl

and

3 boys were considered retarded and 12 girls and 21 boys low normal. This dif-ference in proportion of boys

(7%) and girls

(4%) rated below normal is significant (p <

.05).

Psychological Examination

Two psychologists from the University of Hawaii gave 85% of the psychological cx-aminations, each being responsible for about half of this group. The remaining 15% were also tested by well-qualified cx-aminers. The tests given were the Cattell

Infant Intelligence Scale and Doll’s Vine-land Social Maturity Scale,13 resulting in

IQ and SQ scores. The median age at

cx-amination was 20 months. The psychologists

U,

0

C 0

0.

Fic. 1. Percentage distribution of Cattell IQ’s and

pediatrician’s assessment of intelligence of 333

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#{163}vuii her lIean

Standard

.lfedian De,ation

IQ ()f!Q

Ilange (f

JQ

0 For these children who are shy, resistant, or

fearful the Vineland test which does not depend

on the child’s co-operation is invaluable. Only 2

of the 14 who had Vinelands obtained SQ’s

be-low 90. The Vineland, however, is not a substitute

for a mental test but is a valued supplement.

682

and pediatricians worked independently of one another.

For 67 of the 681 children retest scores on the Cattell or on Form L of the Stanford-Binet were used in the analysis; 36

re-ceived no score on the first test and 31 were retested because the psychologist believed that the initial score was not representative and a retest might change the score signifi-cantly. The median age at retest was 36

months and ages ranged from 26 to 49 months. The correlation between the two IQ’s for the 31 children who received scores

on both tests is fairly high (r = .68) and is significant at the 1% level. Since the only children retested were those whose first tests were of questionable validity, this re-lationship suggests a fair degree of relia-bility for the Cattell IQ’s.

There is probably no age period between birth and maturity at which it is more

diffi-cult to secure a valid mental test score than at the end of the second year of life. The younger child finds the test material

in-trinsically interesting and is, in fact, often

fascinated by it and responds accordingly.

The older child (3 years or more) is also

usually highly motivated to do his best. He

not only finds the tasks interesting and chal-lenging but he wants to succeed. Although testing is difficult between 18 months and 3 years, this is an age period when assess-ments are often needed since it is during this time that parents and others are likely to become concerned and want to make

plans for a child who is developing slowly. It is of considerable interest, then, to know for what proportion of children of this age group it is impossible to obtain an adequate mental test score. On this project there were

16 children for whom the psychologists were not able to obtain an IQ which they thought was adequate, 11 were retested but again without success. This finding

sug-gests that between approximately 18 months and 3 years when co-operation is at a low ebb because of shyness and/or

“negativism” 1 to 2% failure to secure a rep-resentative IQ is to

be expected.#{176}

At the end of the 2-year mental test, the

psychologists recorded an estimate of the child’s current intellectual status by check-ing one of the following : above normal, normal, questionable, below normal. These ratings reflected so closely the Cattell IQ’s

that they did not add any information al-though comments were frequently helpful. It has been stated repeatedly and most re-cently by Oppenheimer and Kessler that a clinical judgment based on tests would be

superior to the obtained scores since co-operation is not always easy to elicit in the early years. Our findings, based on a large

group of children tested during an age

pe-nod when co-operation is most dfficult to elicit, suggest that the examining psychol-ogist usually believes that the obtained IQ is the best estimate he can give.

Distribution of Cattell IQ’s

In contrast to the distribution of pedia-tricians’ ratings, the Cattell IQ’s cover a

wide range (30 to 157) and, as would be

expected, are more differentiating. I

low-ever, the IQ’s of 604 children (89%) fell into

the normal range of 80 to 120 (Fig. 1). The performance of 6.0% of the children was perior with IQ’s of 120 or above. At the

other end of the scale, 3.7% obtained below

normal IQ’s (between 70 and 79); and 1.6% might be considered retarded with IQ’s be-low 70.

The mean, median, standard deviation, and range of IQs are as follows:

Boys

Girls 333

348 97

100

100 100

13 12

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40

C

0 30

0

. 201 C

0 101

a-0

110-09 119

Vineland SQ

683

The distributions of the IQ’s and of the

pediatric assessments differ with respect to

th( larger proportion of children rated as

normal or low normal by the pediatricians and accordingly a smaller proportion of

children rated at the extremes as superior

or retarded. Tile two distributions are in

agreement in describing a larger proportion

of males than females as low normal or

re-tarded.

Distribution of Vineland Scores

The Vineland Social Maturity Scale

eoi-sists of items covering the habits, activities,

and achievements appropriate to each ‘ear

of life from infancy to adulthood.13 In

con-trast to testing methods that require

partici-pation of the child, the Vineland may he

secured from an informant, usually the

mother of the child. She is asked if the

var-iOtls items are consistent with the child’s

behavior. Since the child himself plays no

direct role in the test situation, poor co-operation, a common complication in

as-sessing the intelligence of children at this

age. is avoided.

A comparison of tile distribution of Vine-land and Cattell scores is of interest. The two tests show a statistically significant cor-relation (at the 1% level) both for boys (r

.52) and for girls (r

.54).

The \7ineland

SQ’s (Social Quotients) were higher on the

average than the Cattell IQ’s. The mean,

median, standard deviation, and range of

Vineland SQ’s are as follows:

.

.\u,nl)er .ifean

SQ

.

.Sfedian

SO

Standard

. .

Deviation ofSO

Range of

SQ

Bos 321) 114 114 1.5 59-168

(;irls 341 118 117 14 60-88

As was observed in the Cattell IQ

dis-tribution, more boys than girls earned low

SQ’s on the Vineland. Nine per cent of the

boys and 7% of tile girls obtained SQ’s of

100 or less, while 45% of tile girls and 33% of the boys obtained SQ’s of 120 or above.

Fie. 2. Distribution of \Tineland SQ’s for 329 boys

dfl(l 34 1 girls, Kauai Pregnancy Study.

Follow-up at Ages 6 to 9 Years of Children

Assessed Below Normal at Two Years

Follow-up information was provided by

the Division of Mental Retardation of the

Hawaii Department of Health at ages 5-9

years for 60 of the 66 children judged

he-low normal by one or more methods at 2

years. Subsequent IQ’s were obtained for all but 4 of the 36 children with 2-year IQ’s

under 80 and for the 5 with SQ’s under 90;

school progress reports were provided for

all but 2 of the additional 25 children rated

below normal by tile pediatricians. The

cx-aminations were given by psychologists

from the Hawaii Department of Health, Di-vision of Mental Retardation, and the

Uni-versity of Hawaii. Most of the children tested were given the Stanford-Binet Intel-ligence tests.

RESULTS

Pediatricians’ Assessments

and Cattell 10’s

Table I shows the agreement between

the pediatricians’ assessments and the

Cat-tell IQ’s at age two. The over-all correla-tion is not high (r .32) but is statistically

significant (p < .01). Although a similar

proportion of children were judged below normal by each assessment, only a fifth

were the same children! The disparity was

greater for girls than for boys. The

agree-ment for children in the superior group,

al-though of minor importance at this age,

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TABLE I

PEDIATRIcIANs’ ASSESSMENTS OF INTELLIGENCE COMPARED WITH CATTELL IQ’s, KAUAI PREGNANCY STUDY

Pediatrician’s Assessment

Catlell IQ

I

Total

Uer 70 70-79 80-89 90-99 100-109 110-119 1O+

Num-

Percent-Boys Girls Boys Girls Boys Girit Boys Girls Boys GirLn Boys Gi,l.n Boys Girls age

Superior Boys Girls Normal Boys Girls Low normal Boys Girls Retarded Boys Girls Total Numl,er Percentage 0 S 7 .1 0 1 1 4 1.1 0 1 4 0 16 4.8 0 S 1 0 9 .6 0 58 0 60 18.0 0 35 5 0 40 11.5 1 67 S 1 7 1.6 0 95 3 0 98 Ill 8 0 1QI 36.3 117 0 11 34.8 0 40 0 0 40 1.0 50 0 0 5 14.9 1 15 1 0 17 5.1 0 4 0 0 4 6.9 4 4 30.5 331 1 Fl 3 1 681 . . I.2 1.! 91.6 95.1 6.3 3.4 0.9 0.3 .. .. Pediatricians’ Assessments

and Vineland SQ’s

The pediatricians’ ratings of intelligence are compared with the Vineland SQ’s in

Table II. Defining an SQ of under 90 as below normal, there was less agreement be-tween the Vineland SQ and the pediatri-cians’ assessments as to which children were below normal than for the Cattell I’Qs; and again, agreement was poorer for the girls

than the boys. The over-all correlation of .33 was the same as that found between the Cattell IQ’s and the pediatric assessments, and was statistically significant (p < .01).

The rather poor agreement between the

pediatricians’ ratings and the test scores suggests unreliability in the ratings or test

scores, or both. The physicians made their judgments on a relatively small time sample of the child’s behavior; while the psychol-ogists had to elicit the co-operation of the often negativistic or shy 2-year-old for a good test. However, both (a) the test-retest correlation of .68 and (b) the moderate cor-relation between the Cattell IQ’s and the

Vineland SQ’s (r .53, which is the same

as that usually found between these tests

for older children) attest to the fact that the 2-year IQ’s are fairly reliable. And it is

highly probable that the pediatricians’

judg-ments have greater validity than the

agree-ment coefficients suggest. It was thought that the assessments and the test scores may be complementary; that IQ’s might

help the pediatrician to sharpen his ap-praisal of low-level mental functioning much as laboratory tests or x-ray’s help in the diagnosis of disease.

We therefore sought to determine whether judgments which take into ac-count both the pediatrician’s rating and IQ

may be more predictive than those based on a pediatrician’s rating alone. One way of validating appraisals is to find whether

children judged below normal by the

pedi-atrician or test scores, or by both, are likely

to maintain that status during the ensuing

years.

School Progress of Children Judged Below

Normal at Two Years

Two-year assessments are compared with outcome at the time of the school

fol-low-up in Table III. This table shows that

46% (16 out of 35 children) judged below normal by pediatricians at age 2 earned low

IQ’s or do poorly in school at ages 5 to 8

years. If the Cattell tests given the

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TABLE III

ASSESSMENT OF INTELLIGENCE AT AGE Two BY FOLLOWUP STATUS AT Six TO NINE YEARS, XAITAI

PREGNANCY STUDY

Assessment of Intelligence

at Age Total Study Group Children with Follow-up’ Follow-up Status

Below Average Arerae

p C g belou Areragc lQt tinder 70

IQf No IQ,

Poor School Work IQt 80 or More .vo IQ, Arerage or Btter School JJork Total

Total Below Normal by:

Pediatrician

IQ

SQ

Below Normal by Pe4iatrician:

IQ under 80

SQ under 90

SQ90 orabove

lQ8oorabove

SQunder9o SQ9oorabove

Psych. assess. normal

Psych. assess. below normal

Normal by Pediatrician:

SQunder 80

SQunder9o

SQ 90orabove IQ 80 or above

SQ under 90

SQ 90 or above

681 60 9 4 7 0 0 33.3

45.7 40.6 30.0 73.0 100.0 40.0 30.4 0.0 31.8 5.0 30.0 0.0 37 36 0 1 35 3 O 1 9 9 7 9 0 4 3 0 7 0 0 0 3 19 5 3 16 0 5 0 0 0 16 1 15 1 3 0 7 3 23 I Q4 17 7 4 7 3 3 1 16 6 0 7 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 7 0 7 4 S 0 0 3 0 0 0 0 0 16 7 I7 60 5 613 7 13 ‘ 5 ‘ 0 0 ‘ 0 ‘ 3 1 ‘ 0 U 0 0 ‘ 0 S 4 0 1 0 U 1 4 S U 4.8 7.7 * 0.0 S

S Follow-up limited to children who at age were called below normal by pediatrician. had IQ’s below 80 or SQ’s below 90.

ton the Stanford-Binet.

sole predictor at age 2, 50% (10 of 20) of

the low-scoring children would be below average on the follow-up. The low cutoff point for the Vineland (20 cases with SQ’s below 90) accounts for seeming higher pre-diction on this scale.

The next question is whether the

ac-curacy of the predictions of poor school performance could be increased if

pedi-atricians had available to them the IQ’s and

SQ’s. Table

III

shows that 75% would have

been correcfly predicted if the pediatricians

could have taken the Cattell IQ’s into ac-count in making their assessments (9 out of 12 low by both assessments). Likewise, if the Vineland SQ’s could have been taken

into consideration in addition to the

pe-diatricians’ own judgments their prognosis

would have been improved. If the

pedi-atrician considered as retarded only those

children whom he would rate below normal

and whose scores on the Cattell were below 80 and on the Vineland below 90, he would be 100% correct. This means that if a child is judged below normal by all three criteria,

a perfect prediction of below average at

6

to 9 years might be attained. This result has important implications since it means that each method selects some low cases and, in a doubtful diagnosis, the added in-formation might add considerably to the

accuracy of the prognosis. However, let us hasten to add that the total number of

be-low average children for whom there is complete agreement on prediction from age 2 is only 7; while as many as 20 of the 60 children “suspected” at age 2 by at least one

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687

date has included only the 60 children

judged below normal by one of the criteria used at age 2.

School results are not as yet available for the 615 children considered normal at 2

years by all criteria. Judging by results

from longitudinal studies of mental growth, a small proportion of the 615 normal 2-year-olds will be testing well below aver-age by age 6 to 9 years and will not be

able to keep up in school. This is the group whose potential for mental growth is less

than average. If these children are retested repeatedly during the pre-school years, their IQ’s decrease a little with each test

until finally their status is substantially

below the average of the

Frequently these children come from

fami-lies where they are cherished and

stimu-lated during the early years but the

fam-ily ability or potential is limited and the

child’s school progress tends to fall in line

with the ability of his parents as judged by

their education and socioeconomic status. It is unlikely that it will ever be possible to

make accurate predictions for all school-aged children from assessments or tests given under 2 years, but certain children

may be identified this early: children whose

rate of development is markedly slow even

during infancy and children with

neurologi-cal deficits.

To round out the picture we hope to

carry out a follow-up of the entire group to determine their physical and mental functioning in the early school years. These

findings together with the extensive infor-mation already collected concerning their prenatal and birth histories and the social environment may help to elucidate the

in-fluences of various factors on development.

Factors Related to the Assessments of 2-Year-OIds’ Intelligence

In an attempt to identify the factors

which may have influenced the

pedia-tricians’ ratings and mental test scores, we have considered the characteristics of three groups of children:

Group I : Rated below normal in intelli-gence by pediatrician, IQ’s also under 80.

Group

II:

Rated normal in intelligence

by pediatrician, but IQ’s under 80.

Group

III:

Rated below normal in intelli-gence by pediatrician, but IQ’s 80 or more. Group I includes 9 boys and 3 girls. This sex difference suggests that some of

the boys may have been immature rather than deficient in intelligence. The

follow-up results confirm this suspicion since all 3

of the girls were noticeably retarded at 6 or 7 years while 3 of the boys were func-tioning normally. The pediatricians

con-sidered all 12 children in Group I to be slow in their speech development at 2

years, 10 to be of low physical status, and

7 to be atypical in their motor development

(

walked late, lacked muscle tone, or were hypotonic). Two of them had severe

phys-ical defects: cretinism and pituitary

dwarfism. Perhaps the most interesting

children in this group are the 3 boys who

were testing normally at 6 or 7 years of

age. The pediatrician and psychologist both mentioned the cultural impoverish-ment and maternal neglect of one of these

3 children and in a second case, the psy-chologist reported that the child was very shy and unco-operative. These factors are the ones which are most likely to invalidate

a test at this age period when environ-mental stimulation is variable as are the

moods of the very young child.

In the 6- or 7-year follow-up evaluation,

the psychologists made an effort to suggest a cause for the retardation in tile 9 cases:

7 were thought to be brain damaged, one

socioculturally deprived, and one is a cretin with an IQ of 39.

The pediatricians rated the 24 children

in Group II as having “normal intelligence” but their 2-year IQ’s were under 80. We might expect that the IQ’s of these children were low because testing was difficult and the children not co-operative. This was true

for 6 youngsters who were not responsive

because they were either shy or resistant.

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psycholo-TABLE IV

CHARACTERISTICS OF CHILDREN APPRAISED BY PEDIATRICIANS OR PSYCHOLOGISTS AS BELOW NoItIAL AT

AGE 2, KAUAI PREGNANCY STUDY

GrOUpS Constituted According to As8esslnents of Intelligence at Age

Observations at Age and Follow-up at 6 to 9 Years

l: (a) Pediatric and (b) Cattell IQ

-Group I

(a) Below Normal

(b) JQ Below 80

Group II

(a) Normal

(b) JO 1?eliw SO

Group 111 (a) Below Normal (b) 10 50 or Above

12

9

3

24

14

10

25

15

10

10 (83%) 4 (17%) 17 (68%)

12* (100%) ii (46%) 1.5 (60%)

7 (58%) 1 (4%) 9 (36%)

5 (4%) 5 (21%) 3 (1’2%)

4 (33%) 13 (54%) 7 (28%)

Total in Gronp

Boys

Girls

Observation.s at Age Pediatrician’s evaluation

Low physical status

Slow speech development

Abnormal or slow motor development

Psychologist’s evaluation

Organic involvement or possible brain damage

Adverse environmental factors

Follow-np at 6-9 yearst

IQ 100 or above 90-99

80-89

70-79

60-69

59 or l)elow Incomplete

With follow-up

No follow-up

Mean IQ

IQ 80 or above

IQ 90 or above

Average or above school work

School Work

2 Q Above average

0 4 14 Average

1 10 6 Slow

0 4 1Inattentive

4 0

1 0

12 20

0 4

67 87 Not available

3 (25%) 16 (80%) Not available

2 (17%) 6 (30%) Not available

2** (17%) 11 (55%) 16 (70%)

* Includes two children called retarded intellectually by pediatrician but without specific comments with regard

to speech ;one was a cretin and the other a pituitary dwarf.

t Stanford-Binet IQs.

Child is attending school for the mentally retarded.

** School performance known for 11 of the 12 children.

688 ASSESSMENTS

OF INTELLIGENCE

gists’ comments suggest the former

inter-pretation. Our interest in Group II is in determining whether the low scores on the test reflect the transitory contrariness of the 2-year-old or whether these children are indeed slightly retarded. The test per-formance at school suggests that this group

is actually of below average ability since only 30% of them obtain IQ’s of 90 or above later. “Brain damage” was mentioned for

two of these children with low scores while

“cultural deprivation” and “emotional

prob-lems in the family” were reported for other youngsters. A question here is whether cog-nizance should be taken of low test scores at 2 years when the pediatrician considers the child normal. These results suggest that test scores below 80 even at the 2-year level should be noted and taken seriously

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two-ARTICLES

689

thirds, of children testing below 80 at 2

years may not be capable of average

aca-demic work when they get to school. Group III is perhaps of greatest interest to the pediatrician. These are the 25 chil-dren whose normal IQ’s are in contrast to the pediatricians’ ratings of below normal

intelligence. Many of these children have

physical status and slow in talking. One

poor in speech development (15 out of 25). Ten of the 25 children were both of poor

physical status and slow in talking. One

child had congenital heart disease. Of the remaining 3 who were rated normal phys-ically and seemed normal in speech de-velopment, the pediatrician observed “little

spontaneous activity,” “hyperactive

re-flexes,” and “mother not too bright.”0 The tests proved of great value in modifying the

pediatricians’ assessments since two-thirds

of this group with follow-up was doing

average or better work in school. This

find-ing clearly suggests that the pediatrician should not rely entirely on his own judg-ment in diagnosing mental retardation if a major decision concerning the child’s

wel-fare is to be made.

Comparison of the three groups

sug-gests the value and limitations of both

the pediatricians’ evaluations and the

2-year mental test scores in predicting low IQ’s or slow school progress. The

impres-sive fact that emerges is that (a) when both

agree prediction is good; (b) a test score which is definitely low should not be too readily discounted even if the pediatrician

thinks the child is “all right”; and finally

(c) these findings suggest that mental test scores would appear to have their greatest value to the pediatrician in modifying his prognosis of slow development.

The question arises as to whether the results would have been significantly dif-ferent if the pediatricians’ judgments had

a Although prematures were not included in

the comparison of pediatricians’ assessments and

IQ’s because of the problem of correcting IQ’s

for degree of prematurity, we found that

pedia-tricians rated over 20% of the prematures below

normal compared with 5% of the matures.

been based on several observations of the children rather than on the one made in

this study since it is not likely that they

would ordinarily make a diagnosis of slow development or mental retardation on the basis of a single examination. However, a

recent study of Korsch et al.14 suggests that knowing children well did not produce a greater degree of agreement with IQ’s.

They also found that pediatricians most

frequently underestimated IQ’s in

physi-cally ill children and grossly overestimated IQ’s in the mentally retarded. These are

points that are deserving of further study.

SUMMARY

We have explored tile agreement

be-tween pediatricians’ appraisals of intelli-gence and the mental test scores of a group

of 681 two-year-olds born during a speci-fled time period on the Island of Kauai. Only a modest agreement was found be-tween the two types of appraisals but a

de-tailed consideration of the later school per-formance of children assessed as below nor-mal by either or both methods indicates that

(

a) the prognosis is poor for children

as-sessed as below normal by both methods;

(

b) low test scores at two years are some-what predictive and should not be entirely

discounted and (c) most important, the test

scores would appear to be valuable to the

pediatrician who does not want to err in the

direction of giving a poor prognosis for a child who may later prove capable of

ade-quate if not superior academic perform-ance; (d) predictions for boys should be somewhat more guarded than for girls at

this age period.

REFERENCES

1. Oppenheimer, S., and Kessler, J. W. : Mental

testing of children under three years.

Pitni-ATRICS, 31:865, 1963.

2. Bayley, N. : Consistency and variability in the

growth of intelligence from birth to

eight-eenth year. J. Genet. Psycho!., 75:165, 1949. 3. Honzik, M. P., Macfarlane, J. W., and Allen,

L. : The stability of mental test performance

between two and eighteen years. J. Exp.

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690 ASSESSMENTS OF INTELLIGENCE

4. Sontag, L. W., Baker, C. T., and Nelson, B.

L. : Mental growth and personality

develop-ment: A longitudinal study. Monogr. Soc.

Res. Child Develop., 23:No. 2 (Serial No.

68), 1958.

5. Illingworth, R. S. : The predictive value of

development tests in the first year; with

special reference to the diagnosis of mental

subnormality. J. Child Psycho!. Psychiat., 2:

210, 1961.

6. MacRae, J. M. : Retests of children given men-tal tests as infants. J. Genet. Psychol., 87:111,

1955.

7. Terman, L. M., and Merrill, M. A. :

Stanford-Binet Intelligence Scale Manual for the

Third Revision, Form L-M. Boston:

Hough-ton, Mi.fflin, 1960.

8. Bierman, J. M., Siegel, E., French, F. E., and

Connor, A. : The community impact of

handicaps of prenatal or natal origin. Public Health Rep., 78:839. 1963.

9. Bierman, J. M., and French, F. E. : Ecological

influences on infant mortality among

Japa-nese and Filipino immigrants to Hawaii. J.

Trop. Pediat., 9:3, 1963.

10. French, F. E., and Bierman, J. M. :

Probabii-ties of fetal mortality. Public Health Rep.,

77:835, 1962.

ii. French, F. E., Howe, L. P., Bierman, J. M.,

Connor, A., and Kemp, D. H. :

Community-wide pregnancy reporting in Kauai, Hawaii.

Public Health Rep., 73:61, 1958.

12. Cattell, P. : The Measurement of Intelligence

of Infants. New York: Psychol. Corp., 1940.

13. Doll, E. A. : Measurement of Social

Compe-tence. Minneapolis : Educ. Test. Bureau,

1953.

14. Korsch, B., Cobb, K., and Ashe, B. :

Pediatri-cians’ appraisals of patients’ intelligence.

PEDIATRICS, 27:990, 1961.

Acknowledgment

Great credit is due Dr. Louisa P. Howe, who,

as Resident Project Director, was primarily

re-sponsible for planning and overseeing the special

examinations reported in this paper; to the

pedi-atricians and psychologists for their conscientious

work in appraising the children; and to Miss

Myrna Campbell and her staff of Public Health

Nurses in the Kauai Health Department for

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1964;34;680

Pediatrics

Jessie M. Bierman, Angie Connor, Marilyn Vaage and Marjorie P. Honzik

TWO-YEAR-OLDS AND THEIR MENTAL TEST SCORES