BIRTH LESIONS IN IDENTICAL TWINSl

KATHERINE PRESTON BRADWAY, M.A.2Research Assistant, The Training School at Vineland, New Jersey

T H E frequency and severity of intracranial damage present at birth or soonthereafter has received considerable attention in recent years. Studies of the

consequences of such lesions are often limited, however, because of the difficulty ofdistinguishing clearly between that part of behavior which is a result of the lesionand that which is due to native endowment. When accidents or diseases occursubsequent to infant development, behavior before and after the morbid eventmay be compared and the specific effects of the morbidity may be isolated forstudy. One finds it difficult, however, to determine to what extent developmenthas been modified by a birth lesion since in such cases these comparisons are im­possible.

Instances of identical twins in which one of the pair was injured at birth" (andthe other not) afford valuable material for study. Since heredity, presumably themost important variable in individual growth, is substantially identical in suchtwins, gross behavioral differences may be assumed to be the direct or indirecteffect of the injury, the injured twin serving as the experimental subject and theother as the control subject.

Injury at birth may result in motor, mental, or dispositional abnormalities,singly or in combination. In any case, social competence, or the ability to carefor oneself adequately, is usually retarded if the injury is severe. It is sometimesdifficult to establish intracranial damage as an etiology when there is mentalhandicap without motor handicap. Here again the presence of a mentally normalidentical twin as a control subject is of special value in order to eliminate defec­tive heredity as a possible etiology.

At this laboratory there have been available for study two such pairs of identi­cal twins. One twin of each pair was presumably injured at birth, while the otherwas apparently not injured. The injured twin of one pair (girls) manifests severemotor effects but no mental retardation. The injured twin of the other pair (boys)is mentally deficient, but shows no motor handicap. The injured twin of each pairis seriously handicapped socially and requires supervision and care.

The presentation of a study of these two sets of twins illustrates some of theeffects of birth injury on motor, physical, mental, and social development, andalso provides suggestions related to questions of the comparative influence ofheredity and environment on child development.

1 Presented in brief at the annual meeting of the American Psychological Association, Hanover,N. H., September, 1936.

2The writer wishes to acknowledge the help of S. Geraldine Longwell, formerly Research As­sistant, and J. Thomas McIntire, Chief Clinician, in the examination of the twin girls and twin boysrespectively, and to Edgar A. Doll for the study as a whole.

3 The terms "birth lesion" and "birth injury" are used in this paper to refer to intracranial dam­age present from birth or soon thereafter. The influences producing such lesions are not limited toobstetrical difficulties but may be prenatal or postnatal and may be other than traumatic in orizin,

194

BIRTH LESIONS IN TWINS: BRADWAY 195

IDENTICAL TWIN GIRLS4

Jane and Bertha are five-year-old apparently identical twins. (See Figure I.)Bertha is so severely handicapped as a consequence of injury at birth that hermotor performance does not exceed that of a five-months-old infant, although hermental development is apparently normal. Jane shows no serious abnormalitiesresulting from birth.

FIGURE I

JANE AND BERTHA

History

There is nothing in the family history to suggest an inherited predispositionfor the present condition of Bertha. No record of inherited constitutional defectswas found in a reasonably adequate history.

The mother, a primipara, was thirty years of age at the time of the birth. Shewas of frail physique and had suffered from arthritis since the age of twenty.She died from embolism eight days postpartum although in apparently goodhealth during confinement. No significant data were obtainable regarding theearly prenatal history, except that the mother was under competent medical at­tention. At the beginning of the sixth month of pregnancy she was confined toher bed with a heart condition and suffered sciatic pains. The birth occurred two

4 As of April, 1935, when the girls were 5.3 years old.

THE AMERICAN JOURNAL OF ORTHOPSYCHIATRY

months before term; Bertha weighed 3.3 pounds, and Jane 3.5 pounds. Deliverywas reported as "easy," a dry birth without labor pains, and without apparentcomplications. Dilatation began at 7 P.M., and was complete at II A.M. thefollowing day. Bertha's delivery was assisted by low forceps, and required abouttwenty minutes. Jane was born without delay, presumably also assisted by in­struments. The use of anaesthetics was not noted. A single placenta was reported.

Both children were cared for in incubators. There were no recorded neonatalsymptoms of motor disturbance, and no difference between the infants was noteduntil six months postpartum, at which time Bertha's behavior indicated a spasticcondition. Her motor development since that time has been almost negligible.Jane's motor development has been about average, although acquisition of speechwas delayed until she was four years old.

Examination

These twins were first examined at our clinic in 1933, at the age of three years.They were examined twice in 1934, and again in April, 1935. They resemble eachother strikingly in general appearance although Bertha is slightly smaller thanJane in nearly all anthropometric measurements, and of course, much less active.At four years Jane was more than a year advanced in height and weight (Smedleynorms) while Bertha was about a year retarded. Both have shown average physi­cal growth since then. Comparative measurements are closely similar for thorax,legs, feet, arms, hands, and fingers. The head forms are dolichocephalic; thecranial content for Bertha is slightly less than for Jane (1026 cc. and 1106 cc.respectively). Both have grey-brown eyes with internal squint, light-brown finehair, clear skin marked by a few moles, saddle palate, prominent and high fore­head, widow's peak in hairline, and double cowlick. Fingerprints show generalsimilarity in corresponding fingers except the fore-fingers.

A neurological diagnosis of probable birth injury (petechial hemorrhage type)on Bertha made by Dr. Winthrop M. Phelps in 1933 has remained unchanged inlater examinations, a mixed case of spasticity with athetosis, with almost novoluntary motor control. As noted above, her motor abilities resemble those of afive-month-old infant, and although in 1935 there is less spasticity and morerelaxation than there was in 193.1, there is little indication of improvement sincethen in motor performance. (In terms of normal motor development at the in­fant level, there has probably been less than a month's improvement.) She holdsup her head uncertainly for brief periods, turns her head with some difficulty,raises her left arm with difficulty, and when supported at the shoulder is able tobear her weight on the right leg. She is unable to raise her right arm, to sit with­out support, to rise to a sitting position, or to take stepping movements. Sheuses her arms very little in reaching and grasping. Speech is limited to "yes,""no," "dada," and "mama," and these words are articulated with difficulty.Jane is slightly awkward, but her general motor control is approximately average.

At age 5.3 years Bertha scores .6 years on the Vineland Social Maturity Scale

BIRTH LESIONS IN TWINS: BRADWAY 197

while Jane scores 5.0 years. Bertha's successes and failures range from threeweeks (in self-help) to two years (in play activities) while Jane's range is fromthree years to six years.

The inferiority of Bertha in social maturity seems entirely due to her motorand speech handicaps, and not to inferiority of intelligence. In fact, despite hermotor handicaps, Bertha appears rather more alert mentally than Jane. Formalmental examination of Bertha is difficult, but all her reactions give a positiveimpression of normal mental power, and successive estimates of her mental abil­ity since 1933 indicate average normal mental development. She shows markedspontaneity and keen interest in what is going on around her, and attends readilyfor prolonged periods in matters which concern her. Verbal comprehension is atleast average and has shown a normal rate of increase during the past two years.Her memory seems keen and average; recognition of familiar objects is appar­ently easy; discrimination for people, places, and situations is explicit. She has agood sense of humor, is playful, and responds favorably to social situations.

Repeated examinations of Jane have placed her mental ability about one yearbelow her life age. However, when due allowance is made for individual reactionsand for uncooperativeness, her mental level rises to within normal limits, hercorrected Binet I.Q. being about 90.6 Her mental development seems to be occur­ring at a rate corresponding to the estimated LQ.

Comparison of the personalities of the two girls brings to light some interest­ing possibilities regarding the psychological effects of their condition. Observersagree that Bertha's personality is more pleasing than Jane's, and that her emo­tional reactions seem entirely normal. She is very cooperative and displays sus­tained effort to the point of marked fatigue. Jane reveals an impish, somewhatmischievous disposition which is reflected in negativism and relative lack of co­operation. Report of the home environment indicates that Bertha receives moreattention and encouragement than does Jane. Bertha has responded favorablyto this attention and has adjusted well socially, with some social compensationfor physical inferiority. Jane, on the other hand, reveals inferiority reactionswhich are not warranted by her general ability and seems to draw attention toherself by an attitude of contrariness.

IDENTICAL TWIN Bovs!Jim and Burton, identical twin boys, are 13 years of age. (See Figure 2.) Ex­

amination of Jim has revealed no abnormalities. Examination of Burton hasyielded a diagnosis of mental deficiency, without motor impairment, due to birthInjury.

History

These twins come of a family in which there is no suggestion of defectiveheredity. The pregnancy, which was the mother's first, terminated at 8 months.

6 Binet examination a year after this was written yielded an uncorrected I.Q. of 91-6 As of November, 1935, when the boys were 13.8 years old.

THE AMERICAN JOURNAL OF ORTHOPSYCHIATRY

The weights of the boys were about average for. full term infants; Jim weighed7.3 pounds, and Burton, 6.3 pounds. Eleven hours after the onset of labor Jimwas delivered with apparently little difficulty. Delivery of Burton was instru­mentally assisted fifteen minutes later, a breech presentation. A single placentais recorded in the hospi tal records.

No neonatal abnormalities were observed in Jim. In contrast, Burton was slug­gish and rigid with deficient animation and muscular twitchings. He was inca­pable of nursing, and bowel elimination was delayed for several days after birth.

FIGURE 2

JIM AND BURTON

Jim's development was not unusual, whereas, Burton's development revealedcumulative retardation. He did not hold up his head until seven months, nor sitalone until ten months, nor stand until fifteen months, nor walk alone untiltwenty-three months. During infancy he frequently lay for long periods inertlyon his back. He attended school six years with little success; he repeated gradesI, II, and III. Binet M.A. at 8.7 years was 7.0, I.Q. 80. Both boys have had ex­cellent health without sensory or motor impairment.

ExaminationOur clinic first saw these boys in March, 1935, when they were thirteen years

old. Application for admission to The Training School was made at that time

BIRTH LESIONS IN TWINS: BRADWAY 199

for Burton, and he was admitted soon afterwards. Jim has not been examinedsince the initial visit, but Burton was given another clinical examination in No­vember of the same year.

The boys bear a striking resemblance to each other, so much so that one iseasily mistaken for the other. Both have light-brown hair, hazel brown eyes,freckles over nose, similar skin coloring, similar dentition, broad pointed tongues,identical cowlicks. The shape of their hands is similar, and they both have un­usually large fingernail moons. The fingerprints of the two boys show crossedtendencies, that is, Burton's right fingerprints are more like Jim's right onesthan like his own left ones, and vice versa. Disease history reveals that both boyscontracted scarlet fever followed by mastoiditis at exactly the same time (agefour years).

Despite the striking general similarity and identity of certain features, exami­nation at age 13.2 years revealed that Jim excelled Burton in physical, social,mental, motor, and educational development. Burton was 1.5 years advanced inheight and weight (Smedley norms); Jim was 2.0 years advanced. Burton'scranial content was less than Jim's (1336 and 1456 cc. respectively). Burtonwore shoes size 5!; Jim wore shoes size 6 of a greater width. Measurements ofgrip and vital capacity (in terms of age norms) showed Burton 1.8 years aboveage and Jim 2.2 years above age.

On the Vineland Social Maturity Scale at age 13.2 years, Burton scored 7,4years, S.Q. 56, while Jim scored 15.0 years, S.Q. 114. Re-examination of Burtoneight months later showed no increase. He is dependent on others for washinghis hair, for selecting his clothes according to occasion and weather, and for goingaround town. He does not read, write, or tell time. The games he enjoys are atabout a seven-year level.

At age 13.2 years, Burton attained a Binet M.A. of 6.7 years, I.Q. 51. Re­examination eight months later showed no increase in M.A. Jim at the same ageattained a Binet M.A. of 13.I, I.Q. 98. On performance tests Burton scored aboutsix years, showing a slight motor inferiority as compared with verbal ability.

At the time of admission Burton was given a neurological examination by Dr.Winthrop M. Phelps which revealed no motor disturbances. Clinical examinationand consideration of history yielded a diagnosis of mental deficiency, withoutmotor impairment, due to birth injury.

The personality reactions of the two boys may be significant. They are fondof each other and both enjoy being mistaken for the other. Jim has tried to shieldBurton from the teasing of his playmates. He tries to cover up Burton's in­efficiencies by supplying words and information for which Burton is fumbling.For this reason, Burton, when seen with Jim especially, does not first impressone as mentally deficient. He pretends to know more than he really does, and isquite apt at imitating his brother's actions and remarks. Since Burton has beenin the institution, his inefficiencies have become more apparent and he has de­veloped recognizable inferiority reactions.

200 THE AMERICAN JOURNAL OF ORTHOPSYCHIATRY

DISCUSSION

This study has special value because of the unusual nature of the material.In each of two pairs of apparently identical twins, one twin was injured at birth.The uninjured twin was available as a control subject. One of the injured twinsshows motor handicap without mental handicap, the intracranial birth lesionbeing demonstrable by neurological examination and prenatal history. The otherinjured twin shows mental subnormality without motor handicap, the intra­cranial lesion in this case being presumptive in the absence of other plausibleetiology, and in the presence of a positive history for plausible birth injury. Thesubject material demonstrates the possibility of either type of injury without the

TABLE I

Showing identity" of twins

Bertha and Jane Burton and JimTraits]

Similar Dissimilar Similar Dissimilar

Hair color and form x xEye color x xSkin color x xDowny hair of bodyFreckles xAppearance of blood in skinFollicular processes xTongue and teeth x xForm of face x xForm of ears xForm of hands x xBody build x xMentality xIllness, abnormali ties x xTraits studied by special methods:

Fingerprints x x

• Identity in these traits is used by H. W. Siemens for establishing identity of twins.t Traits which are not checked in either column are those about which there is no information or

concerning which there is some doubt as to the identity.

other and permits a study of the behavioral consequences of both types of in­jury in comparison to each other and in relation to a native endowment whichcan be assumed from the condition of the co-twin. There is no definite evidencethat either of the uninjured twins was reduced from some natively superior po­tential by "injuries" such as affected their siblings.

The significance of this study does not depend upon whether or not thesetwins are identical since many important points are revealed in the comparisonof the injured twins with each other without regard for their non-injured siblings.However, in spite of some minor dissimilarities in each pair, the weight of evi­dence (see Table I) favors a monozygotic presumption in both sets.

BIRTH LESIONS IN TWINS: BRADWAY

TABLE 2Comparisons in histories and measurements" of the twins

201

Factor Bertha I Jane Burton I Jim

Gestation 7 months 8 months

Age of mother at birth 3° 24

Labor (hours) 16 II

Birth Dry Easy

Order of delivery 2 (20 min. aft.) I I 2(15 min. aft.)

Delivery Low forceps ? Forceps. Breech No difficulty

Placenta Single Single

Weight at birth 3.3 pounds 3.5 pounds 6.3 pounds 7.3 pounds

Neonatal Spasms at 6 Normal Sluggish, rigid, Normalmonths deficient anima-

tion, difficultnursing

Height (standing) Year retarded Year advanced Year and a half 2 years advancedadvanced

Sit.stand height ra tio .56 ·54 .5 1 .5 1

Weight Year retarded Year advanced Year and a half 2 years advancedadvanced

Cranial height 121 mm. 124mm. 130 mrn. 138 mrn.Cranial breadth 120mm. 126 mm. 149 mm. IS0 mrn.Cranial length 164 mm. 171 mm, 180 mrn. 190mm.

Cranial content 1026 cc. 1106 cc. 1342 cc. 1468 cc.

Binet M.A. 5 years (est.) 4·5 to 5 years 6.7 years 13.1 yearsBinet I.Q. 100 (est.) (corrected) 51 98

90(corrected)

Social Age .6 years 5.0 years 7.4 years 15.0 yearsSocial Quotient I I 94 56 114

Motor development 5 years retarded About average Average Average

Personali ty Well adjusted Inferior reactions Inferior reactions Well adjusted

• The measurements indicated in the table were taken when the girls were 5.3 years old andwhen the boys were 13. 2 years old.

Comparative data on history and present status of both pairs are presentedin Table 2. The following points concerning birth history are specially note-

202 THE AMERICAN JOURNAL OF ORTHOPSYCHIATRY

worthy. The injured girl was first-born, whereas the injured boy was second­born. Both mothers were primiparae. The birth of both of the injured twins wasassisted by forceps. Both of the injured twins were smaller at birth than theirsiblings.

Both of the injured twins are somewhat physically inferior to their uninjuredsiblings, although physical proportions are similar. At the time of the study theinjured twin girl is two years retarded in height and weight as compared withher sister, while the injured twin boy is about one-half year retarded in heightand weight as compared with his brother. The greater relative physical retarda­tion of the twin girl might be attributed to her physical impairment, as comparedwith the twin boy who has no physical impairments. However, the significanceof the physical retardation in either or both injured subjects is difficult to evalu­ate. It might seem to be ascribable to the effect of birth injury on physical de­velopment, but the evidence elsewhere reported of the possibility of physicaldissimilarity in monozygotic twins makes the evidence in two cases inconclusive.It is noteworthy, too, that the physical development of the injured girl has beenat an average rate during the last 3 years in spite of her motor handicap.

The influence of environment on development is of special interest. Up to thetime of this study the external environment has been much the same for bothtwins of each pair. The study shows, however, the extent to which a severemental or motor handicap can prevent an individual's attaining average socialcompetence. The data for the twin girls show the extent to which mental de­velopment is independent of extreme physical handicap and the consequentlimitations to intellectual expression. In the twin boy, on the other hand, mentaldevelopment has been retarded in the absence of motor limitations to behavioraldevelopment.

The comparison of the personality reactions of the twins suggests the extentto which personality may be affected by extraneous conditions. The inferiorityreactions of the non-injured twin girl in contrast to the good adjustment of hercrippled sister, and the inferiority reactions of the mentally handicapped twinboy in contrast to the good adjustment of his mentally normal brother may havesome implications concerning emotional adjustment. In these two cases mentaladequacy is apparently more important to adjustment than physical adequacy.

Obviously few positive conclusions can be drawn from such limited data.However, the study indicates the feasibility of studying the effects of intra­cranial birth lesions through the collection of data on identical twins of whichone of each pair has been injured at birth. The study may, furthermore, furnishsuggestions as to what other problems in the field of heredity and developmentmight also be so studied.

REFERENCES

I. DOLL, E. A. An/hropome/r.v as an Aid /0 Mental Diagnosis. Vineland TrainingSchool Publication No.8, 1916, pp. 91.

BIRTH LESIONS IN TWINS: BRADWAY 2°3

2. --,-. "Birth Lesion as a Category of Mental Deficiency." Amer. J. Orthopsy­chiat., 1933,3,311-313.

3. ---. "Psychological Significance of Cerebral Birth Lesions," Amer. J.Psychol,1933, 45, 444-452.

4. DOLL, E. A., PHELPS, W. M., AND MELCHER, R. T. Mental Deficiency Due to BirthInjuries. New York: Macmillan, 1932, pp. 289.

5. JENKINS, R. L. "Dissimilar Identical Twins," Amer. J. Orthopsychiat., 1935,5, 3~43·

6. KOMAI, TAKU, AND FUKUAKA, GARA. "Post-Natal Growth Disparity in Monozy-gotic Twins," J. of Heredity, 19,25,421-43°.

7. NEWMAN, H. H. "Studies of Human Twins. I-Methods of Diagnosing Monozy­gotic and Dizygotic Twins." Bioi. Bull. 1928, 55, 283-297.

8. REICHLE, H. S. "Diagnosis of Monozygotic Twinning." J. of Heredity; 1934, 25,33-37·

9. REXROAD, CARL N. "Recent Studies of Twin Resemblance," Psycbol. Bull., 1932,29, 2°4-217.

10. RIFE, D. C. "Genetic Studies of Monozygotic Twins. I-A Diagnostic Formula,"J.of Heredity, 1933, 24,339-345·

II. SIEMENS, H. W. "The Diagnosis of Identity in Twins," ]. of Heredity, 1927, 18,201-2°9·