Personality Resemblances in Adoptive Families

Journal of Personality and Social Psychology 1985, Vol. 48, No. 2, 376-392

Copyright 1985 by the American Psychological Association, Inc. 0022-3514/85/S00.75

Personality Resemblances in Adoptive Families When the Children are Late-Adolescent or Adult John C. Loehlin, Lee Willerman, and Joseph M. Horn University of Texas at Austin

Members of 220 families who had adopted one or more children from a Texas home for unwed mothers at least 14 years ago completed the California Psychological Inventory and the Thurstone Temperament Schedule. Consistent with other recent adoption studies in Minnesota and Texas, there was very little resemblance between parents and adopted children or between adoptive siblings (average correlations about .05). The presence of a biological relationship raised correlations a little, but only a little, to about . 15, suggesting that much of the explanation for personality variation must lie in within-family environmental variation or nonadditive genetic effects. In an earlier study, young adopted children appeared to be better adjusted, on the average, than biological children in the same families. This was no longer true for the late-adolescents and young adults of the present study.

Do biologically unrelated individuals in adoptive families grow up to be alike in personality by virtue of their shared experiences, exposure to similar child-rearing procedures and attitudes, identification with or imitation of one another, and so on? Recent studies of adoptive families suggest that the answer is "very little" (Loehlin, Horn, & Willerman, 1981; Scarr, Webber, Weinberg, & Wittig, 1981). Scarr and her colleagues studied two separate Minnesota samples, one involving mixed-racial adoptions and fairly young children (average age 7 years), and one involving ordinary adoptions and older children (average age 18.5 years). Loehlin and his colleagues studied a sample of Texas adoptive families (average age of children given personality tests, 10.9 years). The first Minnesota study used Eysenck personality scales, the second used several different scales in the introversion-extraversion and neuroticism domains, and the Texas study used ageappropriate questionnaires from Cattell's series. This research was supported by grant BNS-7902918 from the National Science Foundation. We are grateful to the director and staff of the adoption agency and to the adoptive families for their cooperation in the study. Requests for reprints should be sent to John C. Loehlin, Department of Psychology, University of Texas at Austin, Austin, Texas 78712

In the first Minnesota study, the average correlation between a parent and an adopted child on personality scales was .05 and the average correlation between adoptive siblings was .01. In the second Minnesota study these figures were .04 and .07. In the Texas study they were .06 and .04. These average correlations are all slightly positive, so there is evidence that shared family life tends to make biologically unrelated individuals a little bit alike, but it is a very little bit indeed. The shared effects of a common family environment, plus the effects of any other experiential mechanisms promoting similarity among individuals, such as imitation or identification, account for only a small fraction of the reliably measured personality variation in these children. This apparent ineffectiveness of shared family environmental factors in shaping personality is consistent with conclusions arrived at by Rowe and Plomin (1981) on the basis of a broader survey of various kinds of evidence, and represents something of a challenge to many traditional views of what is important in personality development (Loehlin & Nichols, 1976, chap. 7). The adoption studies also provide evidence concerning the genes. If genetic factors play a substantial role in personality, one would expect that biologically related pairs of individuals, who also occur in some of these 376

PERSONALITY RESEMBLANCES IN ADOPTIVE FAMILIES

families, would be more alike than adoptive pairs. Sometimes this was so, sometimes not. In the two studies with younger children, resemblances between parents and their biological children (average correlations of .01 in Minnesota and .06 in Texas) look much the same as those between parents and adopted children. The Minnesota study obtained correlations among biological siblings that were somewhat higher than this (average of .19), but the Texas study did not (average of .06). The second Minnesota study did not have biological parent-child and sibling pairs within the adoptive families, but reported such data for a separate control group of ordinary families. These averaged .15 and .20 for parent-child and sibling pairs, respectively. These are reasonably typical of ordinary family correlations reported in the literature: .16 and .18 in a review of early studies by Crook (1937); .13 and .13 in the data from the recent large Hawaii Study of Cognition (Dixon & Johnson, 1980; Loehlin et al., 1981, Table XI). Some of the above figures from the Minnesota and Texas adoption studies suggest a modest role for the genes in personality, whereas some suggest almost no such role. In both the Texas and Minnesota studies, correlations of parents with young children fell in the latter category. Given the difficulties of comparable personality measurement across this age range, and indeed of any kind of personality measurement at the younger ages, perhaps this finding should be discounted. (In the Texas study, restriction to subsamples of well-measured children led to higher correlations.) The second Minnesota study provides evidence that low correlations involving adopted children are not just a function of young ages, and that a matched group of ordinary biological families yields correlations fairly typical of those which have been found in other studies of such families. There remains, then, some uncertainty in the interpretation of these results: Is the important difference the one between younger and older children, between adoptive and ordinary families, or between Minnesota and Texas? A study of biologically related and unrelated individuals in a sample of older

377

adoptive families from Texas should shed light on these issues. Such a study was undertaken. A study of this kind could also serve to address another issue. In the earlier Texas study were several pieces of evidence, not all very impressive statistically, but independent and converging, to suggest a rather curious and paradoxical effect of the genes on personality (Loehlin, Willerman, & Horn, 1982). In the extraversion domain the results were straightforward: The adopted children resembled their biological mothers. In the emotional stability domain, however, the results were paradoxical: Children of more disturbed biological mothers tended to be more stable and better adjusted than children of less disturbed mothers. This also was reflected in comparisons of the adopted children with biological children in the adoptive families. The adopted children tended to be better adjusted on the average than the biological children, even though their own mothers were on the whole much less well adjusted than the adoptive parents. It was suggested that this sort of apparently paradoxical outcome might result if what were inherited were not emotional instability per se, but rather a sensitivity to or dependence on the early environment, which led the adopted children to an excellent adjustment in the warm and supportive environment of the adoptive home, but had led their mothers to an unfavorable adjustment in the presumably less benign environment in which they had been reared. If such a view is correct, a real question arises as to what will happen when such children grow older and tend to interact with a more varied and less uniformly supportive environment. Will the difference in emotional stability between the adopted and biological children disappear or even reverse itself? A study of an older sample of adoptees from this same population could also provide some evidence on this point. Method Families adopting children from the same agency used in the previous Texas study were contacted by mail. Only families adopting children prior to 1966 were approached so that the same tests could be used for children and parents. This resulted in a sample largely from adoptions

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J. LOEHLIN, L. WILLERMAN, AND J. HORN

earlier than those of the previous study, although there was some overlap between the oldest group in the 1981 study and the youngest group in this one. Twenty-six families participated in both studies.

Instruments Two personality questionnaires were completed by the participants, plus a short handedness scale for a separate study. The personality questionnaires were the California Psychological Inventory (CPI; Gough, 1964) and the Thurstone Temperament Schedule (TTS; Thurstone, 1953). The CPI consists of 480 true-false self-descriptive items designed to assess personality traits within the range of normal functioning. Its 18 original scales were derived by a mixture of rational and empirical procedures to measure what Gough calls "folk concepts" of personality, that is traits given common definition in the culture. The scales include a cluster in the area of extraversion/ social dominance (e.g., Sociability, Dominance, Social Presence, Capacity for Status), a cluster in the area of socialization and emotional maturity (e.g., Responsibility, Socialization, Tolerance, Sense of Well-Being), some scales having to do with intellectual qualities (e.g., Achievement via Independence, Flexibility, Intellectual Efficiency), and a few miscellaneous scales (e.g., Psychological-Mindedness, Femininity). The TTS consists of 140 true-false, self-descriptive items, designed to measure relatively permanent traits that can be used to differentiate normal, well adjusted people. The seven traits measured are general activity, vigor, impulsivity, dominance, emotional stability, sociability, and reflection. These traits were identified through a factor analysis of 13 scales of the Guilford personality questionnaires (Thurstone, 1953). The 140 items on the schedule were selected from a pool of existing personality questionnaire items on the basis of relevance to normal personality and the ability to discriminate the top from the bottom third of subjects on the seven traits. The TTS broadens the coverage of the domain of personality by including some important temperament dimensions (e.g., activity) which are not well represented on the CPI. One consideration in the choice of these two particular questionnaires was the availability of data from twin samples that would permit a joint analysis of adoption and twin data. This analysis will be the subject of a separate report.

Sample Selection A total of 758 eligible families were initially sent a letter of invitation signed by the director of the adoption agency. Those agreeing to participate were mailed a packet containing the two personality inventories, along with answer sheets and instructions, and, when appropriate, stamped envelopes for further mailout of questionnaires to family members living away from home. Of the original 758 potentially eligible families, 463 or 61% responded to the initial letter or a follow-up letter, or were reached by a follow-up telephone call. Of these, 293 or 63% agreed to participate and were sent questionnaires. Of this group, 73 dropped out for one reason or another before completing the study, leaving 220 families who constituted the final sample and whose

returned answer sheets constituted the primary data of the study.

Data Quality Answer sheets were carefully hand-checked and cleaned up or remarked as necessary to insure accurate optical scanning. The item responses were transferred by optical scanner to magnetic tape. All scoring of scales was done by computer programs. The Communality (Cm) scale of the CPI, which consists of items nearly always answered in one direction in the general population, was used to screen out invalid responders. According to the CPI manual (Gough, 1964, p. 20) scores of less than 20 on this 28-item scale are rarely encountered in normal use of the questionnaire, so scores lower than this were taken as probably indicative of random or arbitrary responding, getting lost on the answer sheet, or the like. In a few cases where inspection of the CPI answer sheet yielded an obvious explanation of the difficulty (e.g., failure to do both sides of the answer sheet) only the CPI was invalidated, otherwise both questionnaires were excluded. The distribution of the 17 excluded cases is of some interest, because they were disproportionately from the adopted children, particularly the males. The breakdown of excluded cases was: 3 fathers, no mothers, no biological sons, 11 adopted sons, 1 biological daughter, 2 adopted daughters. A reduced level of conscientiousness in the adopted children could conceivably reflect some genetically transmitted characteristics of their biological parents, although one would need to invoke additional factors to explain the sex difference. The overlap of 26 families between this and the preceding study permitted a check on the consistency of personality questionnaire responses over a substantial period of time. In the earlier study, the parents in these families had filled out a shortened version of the Minnesota Multiphasic Personality Inventory (MMPI). This version and the CPI have 116 items in common, so it was possible to examine the consistency of response to these items over the 5- to 6-year interval between testings. The range among the 50 individuals was from 73% to 93% agreement on the 116 items (excluding those few items omitted on one or both occasions), with a median of 84%. If we look at agreement in another way, by items, we can compare the results with those obtained in a study by Goldberg and Rorer (1964). These investigators gave the MMPI and the CPI, 2 weeks apart to a group of students at the University of Oregon. They report itemby-item consistencies across the administrations. The 116 items ranged in their study from 65% to 100% consistency, with medians of 86% for males and 88% for females. For the present group of adoptive parents the range was 58% to 100% consistency for these items, with medians of 84% for both mothers and fathers. Thus the consistency of item response over a 5- to 6-year interval for the present sample is only slightly below the consistency over 2 weeks obtained by Goldberg and Rorer. The results of this analysis also provide some reassurance against errors in data transcription, subject code numbers, or computer data files in either of the two adoption studies.

379

PERSONALITY RESEMBLANCES IN ADOPTIVE FAMILIES A check on consistency of response within the present study data is afforded by the 12 items that are repeated within the CPI. The median levels of agreement on these 12 repeated items in the various groups (whole sample, after the exclusions for low Cm) were as follows: fathers, 88%; mothers, 92%; biological sons 88%; biological daughters, 90%; adopted sons, 89%; adopted daughters, 91%. The same consistency figures from the Goldberg and Rorer study were 89% for males and 90% for females. For late adolescent twins filling out a mailed CPI in the National Merit Twin Study (Loehlin & Nichols, 1976) consistency on the repeated items was 89% for the two sexes combined. All these figures are very similar. By contrast, the group of 11 adopted sons excluded on the basis of low Cm scores in the present study showed a median consistency of 59% for these 12 items, only slightly above the 50% expected by chance. In the excluded group as a whole, 65% (11 of 17) of the individuals had consistency scores of less than two thirds on the 12 repeated items; of the remaining sample, only about 1% (7 of 719) scored that low. As a check on comparability of the samples in the two studies, the means and standard deviations of the subsample of children who participated in both studies were compared with those of the two total samples. Most of the differences in means were small: no difference on the Cattell scales for the first study or on the CPI scales for the second study was as great as .la. There were some slightly larger differences on TTS scales: the subsamples averaged higher on Stable and Impulsive, and lower on Reflective than the total second sample, by amounts ranging from .la to Aa. Because related scales on the CPI did not show similar differences, these may perhaps best be regarded as random fluctuations (n = 36 for the TTS in the subsample). The standard deviations on the personality scales did not appear to differ systematically

Table 2 Distribution of Ages of Children in the Study

Age

Number of adopted children

Number of biological children

Male

Male

Female

Female

49 41 33 15 16 6

7 6 9

2:29

50 43 18 17 7 4

4

2 3

Total

139

160

30

32

14-16 17-19 20-22 23-25 26-28

3 1

8 6 7 6

between the subsample and the whole samples. On the whole, then, it does not appear that the selection in the second study differed markedly from that in the first, in relation to personality variables.

Results The distribution of families in the study is shown in Table 1. Of the 220 families, 47 or 21% contained one or more biological children of the two parents in addition to adopted children. (The seven families in categories B or BB were recruited for the study on the basis of an adopted child who then either elected not to participate or was dropped because of a low score on the CPI Communality scale.) Altogether, there were 299 adopted children in the study, and 62 biological chilTable 1 dren. In the mixed families, biological chilFamilies in the Study dren preceded and followed adopted children Children Adopted Biological about equally often. The age distribution of children in the in family children Families children study is shown in Table 2. The range of ages 94 A 94 0 for the adopted children was from 14 to 36, 150 AA 0 75 with a median of 17.5 years; the biological BA 14 14 14 children tended to run a little older, ranging 11 11 11 AB 0 B 6 6 in age from 14 to 45, with a median of 19.4 ABB 6 12 6 years. The parents' ages ranged from 39 to AAA 4 12 0 76, with a median of 50.2 for the fathers and AAB 4 2 2 48.2 for the mothers. BAB 2 2 4 No socioeconomic data were obtained for BBA 2 4 2 BBBA 2 2 6 this sample, but it is reasonable to suppose ABA 1 2 1 that the parents are similar to those from the BB 0 1 2 previous sample of adoptions from this Total 299 220 62 agency, and thus are above average educationally and occupationally (Horn, Loehlin, Note. A = adopted child, B = biological child; for example, ABB - family with one adopted, then two biological chil- & Willerman, 1982). The means and standard deviations of the dren. Study ifamilies may have other ineligible or nonparticipating children not shown here. present sample were compared to the pub-

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J. LOEHLIN, L. WILLERMAN, AND i. HORN

lished norms for the CPI and TTS, but these comparisons will not be discussed in detail. The normative data for these questionnaires were gathered in the late 1940s and early 1950s, and there is some evidence (Woodruff & Birren, 1972) to suggest that there may have been appreciable cohort changes in the U.S. in self-reported adjustment during the period 1944-1969. They retested a 1944 sample of college students 25 years later, along with contemporary college and high school students. Using an adjustment measure from the California Test of Personality, they found little change in the retested individuals over the 25 years. However, the 1969 student groups scored about a standard deviation below the 1944 group on good adjustment, suggesting a substantial cohort effect. Although the Woodruff and Birren samples were small and subject to possible selection, our own data are consistent with their findings. Our parent groups are roughly in line with the CPI and TTS norms, whereas our child groups, both adopted and biological, tended to score below the norms on those CPI scales marking the adjustment factor, most notably Weil-Being, Self-control, and Good Impression. The differences from the norms on these scales ranged from one-half to well over a standard deviation in the various sex and adoptive status subsamples. (The means and standard deviations for the present and normative samples on the CPI and TTS are given in Appendix Tables A-D.) With regard to standard deviations, which are important for correlational analyses, our samples show no notable tendency for restriction of range relative to the norms. The Woodruff and Birren data do not suggest any marked changes in standard deviation occurring between 1944 and 1969. In this respect the parent-child and sibling correlations in our sample should be reasonably representative of those in the population on which the tests were normed. A possible exception is the CPI Communality scale, which is restricted in the offspring relative to the normative population and may not vary enough among the adoptive parents to correlate meaningfully with anything. It will be recalled that this scale measures a tendency to agree with usually endorsed items. The adoptive

parents did not often mark unusual statements about themselves: Their means of 26.8 and 26.7 on Cm approach the maximum possible score of 28, permitting very little range of variation on this scale. This suggests both that they were fairly conventional and that they took the task seriously, that is, they read and understood the questions, marked the answer sheet properly and so on. Parent-Child and Sibling Correlations Tables 3 and 4 present parent-child correlations for the CPI and TTS scales, separately for adoptive and biological parentchild pairs in the adoptive families. These are in effect partial correlations, after removal of a linear and a quadratic component of age separately in the two generations, and sex differences in the offspring generation. (Actually they were computed as simple correlations on residual scores from the corresponding multiple regressions.) We see again the very low positive correlations between adopted children and parents obtained in earlier studies: The medians are .07 and .06 for the CPI scales and .04 and .01 for the TTS. The total range of correlations for the individual CPI scales is —.07 to .20, and for the TTS scales, -.04 to .11. These children have been exposed to these parents from the first few days of life, but it is has not made for much resemblance. The biological parent-child correlations are based on fewer pairings, and so can be expected to be more susceptible to the vagaries of sampling. Nevertheless there is a fairly clear tendency toward higher correlations for the biological pairings in Tables 5 and 6. The medians over the CPI scales are .11 and .15, and for the TTS scales .13 and .05. The last median, for the TTS mother-child correlations, is rather low, but note that several of the individual scale correlations are higher than any of the adoptive mother-child correlations on the TTS. Some scales having appreciable biological parent-child correlations for both mothers and fathers include the first five CPI scales constituting an extraversion cluster (Dominance, Capacity for Status, Sociability, Social Presence and Selfacceptance), Achievement via Independence, and TTS Vigorous. On the whole, the average

381


Table 3 Adoptive and Biological Parent-Child Correlations, CPI Adoptive Scale

Father-child

Biological Mother-child

.04 .20 .08 .18 .04 .13 .06

Dominance Capacity for Status Sociability Social Presence Self-Acceptance Sense of Well-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency PsychologicalMindedness Flexibility Femininity Median Pairings

Father-child

.13 .18 .20 .42 .20

-.04

.09 .01 .06 .07 .00 .05

.08

.12 .16 .00

.03 .06

-.01

.06 .10

-.01

.03

-.07

-.23

.27 .12 .08 .30 .05 .15 53

-.27

.11 .07 .06 253

.07 241

-.01

.22 .09

-.03

-.07

.27 .17 .04

.21

.07 .07

.06 .12

-.07

-.03 -.01

.13

.10 .14

.25 .18 .15 .26 .42 .02 .15 .06

-.16

-.02

-.03

Mother-child

.10 .01 .11 52

Note. CPI = California Personality Inventory. The scores on which this and Tables 4 through 10 are based are residuals after age and age2 have been removed by multiple regression in the parent generation, and age, age2 and sex in the child generation.

levels of correlation for biological parentchild pairs in Tables 3 and 4 are comparable to those found in the literature (M = .14 in Loehlin et al., 1981, Table XI). Sibling correlations are presented in Tables 5 and 6. These are intraclass correlations for

the adopted-adopted and biological-biological pairs, and interclass correlations for the adopted-biological pairs. The numbers given at the bottom of the table are for degrees of freedom within families; the numbers of families contributing to these correlations are 73,

Table 4 Adoptive and Biological Parent-Child Correlations, TTS Adoptive Scale Active Vigorous Impulsive Dominant Stable Sociable Reflective Median Pairings Note. See note to Table 3.

Father-child

.03 .00 .07 .04 .06 .07 -.04

.04 257

Biological Mother-child

.02 .11 .01

-.04

.02 -.03 .01 .01 271

Father-child

Mother-child

.33 .36 .13 .09 .06 .22 -.00 .13 56

-.02 .29 .05 .14 .01 .13 .03 .05 54

382


Table 5

Adoptive Sibling Correlations, CPI Scale

Adopted-adopted

Dominance Capacity for Status Sociability Social Presence Self-Acceptance Sense of Weil-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency Psychological-Mindedness Flexibility Femininity Median

.03 .12 .13 -.05 -.01

.14 -.00

.03 -.06

.07 .02 .07 .11 .07 .12 -.04

.14 .22 .07 76

df

Adopted-biological

.05 .01 -.06 -.12

.05 .12 .33 .10 .03 .04 .26 -.13

.11 -.16 -.09

.04 .04 -.24

.04 47

Biological-biological -.18

.60 .22 .70 -.13 -.03

.61 -.01

.34 .09 .21 -.19 -.47

.23 .50 .32 .28 -.21

.22 15

Note. See note to Table 3.

33, and 13 for the CPI, and 76, 35, and 13 for the TTS. Barring selective placement or special differential treatment, the correlations of adopted-adopted and adopted-biological pairs should be equivalent. Evidence from the preceding study suggests that selective placement based on personality variables is negligible in this population (Loehlin et al., 1982, Table 2). The adopted-biological pairings show a wider variation of correlations across scales; this may only be a function of the smaller sample size on which they are based. The median levels are much the same Table 6

Adoptive Sibling Correlations, TTS Scale Active Vigorous Impulsive Dominant Stable Sociable Reflective Median

df

Adoptedadopted

.03 .10 -.27

.08 -.01 -.21 -.02 -.01

80


Adoptedbiological -.28

.27

-.10 -.05 -.02 -.05

.04

-.05

48

Biologicalbiological

.06 .42 .23 -.42

.27 .38 .08 .23 14

in the two cases (.07 and .04 for the CPI scales and -.01 and -.05 for the TTS). It will also be observed that the typical correlations between adoptive siblings are no higher than those for adoptive parents and children, despite the presence of many more shared aspects of family environment for siblings. With so few cases, the correlations between biological siblings are subject to so much sampling fluctuation that one would hardly wish to take the correlations for individual scales seriously. Nevertheless, the medians of .22 and .23 over the CPI and TTS scales are more or less in line with ordinary sibling personality scale correlations in the literature (M = .17 in Loehlin et al., 1981, Table XI). The results to this point have been presented for children of the two sexes combined, and without differentiating between teenaged children still in the home and the older children in the sample in their 20s and 30s who may be expected to have moved away to some degree of independence of their home and parents. The next four tables will present parent-child correlations subdivided in these two ways. Because of already-small samples of biological pairs, we will present only the adoptive parent-child correlations subdivided in this fashion; thus we will be examining

383


Table 7 Adoptive Parent-Child Correlations by Sex of Child, CPI Mother-son

Father-son

Scale

.02 .25 .12 .18 .04 .01 .07 .03 .13

-.05 -.01 -.08

.11 .15 .02 .18 .05 .29 .10

Dominance Capacity for. Status Sociability Social Presence Self-Acceptance Sense of Well-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency Psychological-Mindedness Flexibility Femininity Median Pairings

Father-daughter

.10 .13 -.02

.07 .00 .05 .13

-.07

.04 .11 .07 .08

-.08

.06 .12

-.05

.05 -.04

-.04

.20 .04

.21 .15 .12 .25

-.15

.12 .17 .05 109

-.06

.11 106

Mother-daughter .00 .18 .09 .02 .04 .03 .05 -.05

.01 .01 .04 .22

.10

-.07

.03 .14 .01 .01

-.03

-.09

.05 131

.10 .07 .08 -.04

.04 140


only possible environmental effects of these variables. Tables 7 and 8 show adoptive parent-child correlations separately for the four parentchild gender combinations. They allow examination of the possibility that (say) identification or imitation may have quite different consequences for like-sex than for oppositesex pairs, or that daughters are more subjected to home influences than sons, or that mothers affect their children's personalities more than fathers do.

In fact, there is little support for any of these possibilities. The typical levels of correlation are essentially the same for like-sex and for opposite-sex parent-child pairs (medians of .11, .04, .06, -.00 vs. .05, .05, .05, —.01). Daughters do not resemble their parents more than sons do (medians of .05, .04, -.01, -.00 vs. .11, .05, .06, .05). Children do not differ in their resemblance to their mothers and their fathers (medians of .05, .04, .05, -.00 vs. .11, .05, .06, -.01). One could doubtless develop interesting hypotheses

Table 8 Adoptive Parent-Child Correlations by Sex of Child, TTS Scale Active Vigorous Impulsive Dominant Stable Sociable Reflective Median Pairings

Father-son

.06 .14 .17 -.05


.06 .04 .04 .06 116

Mother-son

.08 .26 .05 -.11

.09 -.05 -.02

.05 120

Father-daughter

Mother-daughter

-.01 -.14 -.02

-.04 -.02 -.00

.09 .06 .07 -.10 -.01

139

.02 -.04 -.00

.05 -.00

149

384


Table 9 Adoptive Parent-Child Correlations by Age of Child, CPI Father-child 14-19

Scale Dominance Capacity for Status Sociability Social Presence Self-Acceptance Sense of Well-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency Psychological-Mindedness Flexibility Femininity Median Pairings

Mother-child 14-19

.04 .17 .07 .20 .01 .21 .15 .03 .20 .06 .18 .10

-.03

.09

-.05

Father-child 20+

.09 .26 .13 .17 .13

.10 .06 -.04

.06 -.02

.12 .02 .02 .04 .02 .18

.07 .15 .01 .07

-.05 -.05 -.12 -.18 -.16 -.17

.08 -.06

.10 .05

.17 .09 .13 .21 .06 .09 85

-.06

.06 .02 .03 151

-.15

.08 150

Mother-child 20+

-.05

.06 -.04

.19 .06 .02 -.05 -.07 -.01

.08 -.09

.04 -.08

.01 .08 .04 .18 .15 .03 97


to explain some of the configurations observable on particular scales, for example, that sons resemble their parents on Achievement via Independence, whereas daughters do not, but given the considerable likelihood that one would be explaining sampling fluctuation in many such cases, it seems prudent to wait until such findings have received independent support before devoting much effort to their interpretation.

Tables 9 and 10 recombine the sexes of the children, but subdivide the children by age into those aged 14-19, and those aged 20 or over. Are the adoptive parent-child correlations low because of personality changes between adolescence and adulthood? If so, the 20+ group could show higher correlations with their parents. Are the adoptive parent-child correlations low because of the presence in the sample of a large subgroup

Table 10 Adoptive Parent-Child Correlations by Age of Child, TTS Scale

Father-child 14-19

Active Vigorous Impulsive Dominant Stable Sociable Reflective Median Pairings Note. See note to Table 3.

.04 .02 .10 -.00

.17 .07

-.10

.04 162

Mother-child 14-19

.01 .12 -.00 -.06

.01 .05 .02 .01 163

Father-child 20+

-.03

.01 -.02

.08 -.18

.03 .03 .01 91

Mother-child 20+

.04 .14 .05 -.02 -.01 -.11 -.03 -.01

104


385

For the first study, the composites used in no longer living at home? If so, the 14-19 age group should have higher correlations. In the previous report were employed. These fact, neither suggestion is supported by the were produced by simple summation of scores data: The levels of correlation for the two age on factors A (Warmhearted), F (Enthusiastic) groups are essentially the same. Again one and H (Venturesome) for Extraversion; and might generate speculative hypotheses about C (Emotionally stable), O (Guilt prone) and particular scales, to explain why (say) adult Q4 (Tense), for Adjustment; O and Q4 being children seem to resemble their parents in reversed in direction before summing. Beflexibility more than adolescent children do, cause scaled scores were used, with nominal but again, for the same reasons, it seems standard deviations of 2.0, this resulted in approximately equal weights for the compopremature to do so. nent scales. These scales are ones typically showing high loadings on the first two secondComparison of Means of Adopted and order factors, which Cattell calls "Exvia-InBiological Children via" and "Anxiety," in factor analyses of the A comparison of differences in means be- Cattell questionnaire scales (Cattell, 1973). For the second study, the Extraversion tween adopted and biological children is relevant to the second major issue addressed by composite was made up of Cough's (1964) this study. In the previous study, adopted "Class I" CPI scales Dominance, Capacity children tended to resemble their biological for Status, Sociability, Social Presence, and mothers in traits related to extraversion, but Self-Acceptance, plus the TTS scales Domiin the area of emotional stability there was a nant and Sociable. These scales form a paradoxical opposite effect, visible in both strongly mutually intercorrelated set, with within- and between-group comparisons. correlations ranging from .33 to .74 in the Within groups, the more disturbed unwed present sample, mostly above .50. The CPI mothers, as evidenced by elevated scores on scale Well-Being, which Gough places in his the MMPI, tended to have children who Class I, was grouped instead with the Class turned out calmer and more secure. Between II scales, where its intercorrelations say that groups, the adopted children as a whole av- it belongs. These scales formed the second, eraged higher on ratings and scales reflective Emotional Adjustment composite, which of good emotional adjustment than did the contained Well-Being, Responsibility, Socialbiological children in the adoptive families, ization, Self-Control, Tolerance, and Good although there was a large average difference Impression, plus the TTS scale Stable. Comin the opposite direction between the unwed munality, which Gough places in Class II, was excluded on the grounds of low correlamothers and the adoptive parents. The first, within-group results cannot be tions with the remaining scales, although tested in the present study, because the sample these may reflect its restricted variation as was mostly drawn from a period before the much as its content. The scales included in agency routinely gave MMPIs to unwed the Adjustment composite all had positive mothers. There is, however, evidence relevant intercorrelations, in the range of .28 to .72, to the between-groups comparisons. The again with a majority above .50. The scales comparison is complicated by the fact that in both composites were combined with equal different personality measures were used in weight, that is, by weighting by the reciprocals the two studies: inventories from the Cattell of their standard deviations. series in the first, and the CPI and TTS in To check on the agreement of these two the present study. Individual scales in the two sets of composites across studies, the 26 studies do not match up very well on a one- overlapping families were used. There were to-one basis, but jointly they cover a person- 84 individuals in these families who took ality space which has considerable overlap. both sets of questionnaires. The correlations The strategy we will adopt is to create extra- of the two sets of Extraversion and Adjustment version and emotional adjustment composites composites are shown in Table 11. It will be from each battery, and make our comparison seen that the corresponding composites match on these. up reasonably well, considering that the tests

386


Table 11 Correlations Between Cattell and CP1/TTS Composites in Overlapping Sample of Families Composites

Cattell Extraversion

Cattell Adjustment

CPI/TTS Extraversion CPI/TTS Adjustment

.51 .22

.19 .48

Note. N=&4 individuals, including both parents and children. Correlation between Extraversion and Adjustment: Cattell, .38 (n = 95); CPI/TTS, .16 (n = 85).

adopted and biological children might not be reflecting some other variables, such as the difference between all-adoptive and mixed families (all of the biological children are from the latter type of families) or the difference between single- and multiple-child families (again, all of the biological children come from the latter). Not all the above questions can be given clear answers from the present data. Questions of the first sort can be settled convincingly only by a longitudinal study in which the same instrument is given to the same subjects on two or more occasions. The best we can do here is look at the small group of subjects who were in fact tested twice by virtue of their participation in both studies. Table 13 addresses change in the adopted and biological children from the 26 twicetested families. The only change between the two occasions of testing that is statistically significant by conventional standards is that the adjustment of the adopted children is worse at the second testing than at the first (p = .03, by matched-pairs / test). This is consistent with the cross-sectional results for the full samples. In this particular subsample, however, the difference in favor of the adopted children is not present at the first testing and so a change in the direction of the difference does not occur. Table 12 addresses the other questions raised. It presents mean differences for the individual CPI scales, obtained in two ways. One is for all adopted and all biological children, as in the comparisons reported in Table 14. This is provided for the benefit of readers who may wish to see the results for

were taken 5 or 6 years apart and that the internal consistency of the Cattell composites is not especially high. It is also evident that the two dimensions are moderately positively correlated with one another, as they usually are in the literature, and as they are within each of the two testings. Table 12 answers the question: Did the average differences in favor of adopted children that were observed in the previous study persist in the present study with older children? The answer is that they did not. The differences in the first study are statistically significant by an overall multivariate analysis of covariance (MANCOVA) (approximate F by Pillai's test 5.40; df= 2, 308, p = .005); each is significant by univariate F tests (Fs of 10.54 and 4.27, both with 1 and 309 df, p = .001 and .04). The differences in the second study do not reach conventional levels of statistical significance, either by joint test or for Adjustment separately (multivariate F(2, 315) = 1.62, p = .199; univariate F( 1, 316) = 2.88, p = .09). The difference on the Emotional Adjustment composite that does exist, however, is in the opposite direction from that observed in the first study: The adopted children, on the average, no longer score as Table 12 better adjusted than the biological children Differences Between Means of Adopted and in the adoptive families—if anything, they Biological Children in Previous and Present Studies score as less well adjusted. One may reasonably ask whether differPrevious study Present study ences of this sort represent changes in indi- Composite viduals as they grow older, or whether they Extraversion .41 -.00 might represent all or in part differences of Adjustment .27 -.23 some other kind, such as differential selection Differences are in standard score units; a positive in the two samples, or differences in meaning Note. difference means adopted children score higher. Differences between putatively corresponding composites adjusted for age, age2 and sex. N = 218 adopted and 96 from the two studies. One might also ask biological children in previous study; N = 263 adopted whether the apparent differences between and 58 biological children in present study.


387

Table 13 Mean Scores at First and Second Testing for Adopted and Biological Children in Twice-Studied Subsample First study

Second study

Composite

Adopted

Biological

Adopted

Biological

Extraversion Adjustment

-.16 -.24

.19 -.06

-.07 -.84

.34 -.18

Note. Standard scores over the 84 individuals in the twice-tested families, n = 24 adopted, 11 biological children.

some of the individual scales that enter into it does not appear that the latter have resulted the composites there reported. The second artifactually from differences between allcolumn of Table 14 controls for the possibility adopted and mixed families, or between onethat some of the mean differences might be child and plural families, between-family differences, that is, differences The individual CPI scale showing the largest between all-adoptive families and those with difference in both comparisons in Table 14 both biological and adoptive children, or dif- is Socialization; the adopted children scored ferences between only-child and multiple- lower, that is, as less well socialized. This is child families. The analysis in the second the scale that Gough developed to distinguish column takes one adoptive and one biological between juvenile deliquents and nondelinchild from each of the 33 families with at quents. A wide variety of prison and other least one of each (if there was more than one, disciplinary problem populations, both male the eldest was used); thus these comparisons and female, including a sample of unwed are entirely within families. Because the mothers, have been shown to have low scores within-family differences are on the whole at on this scale (Gough, 1964). Because of the least as large as the total sample differences, failure of an overall multivariate test on the Table 14 Mean Differences Between Adopted and Biological Children on CPI Scales Scale

Total sample

Within-family pairs

Dominance Capacity for Status Sociability Social Presence Self-Acceptance Sense of Weil-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency Psychological-Mindedness Flexibility Femininity

-.15

-.31 -.06 -.39

.00 -.08

.01 .15 -.18 -.19 -.32 -.15 -.18 -.01 -.16 -.18 -.27 -.15 -.02 -.06 -.01

.06 -.08 -.21 -.19 -.50 -.13 -.03 -.00 -.46 -.38 -.16 -.08

.35 .27

-.00

Note. Ns for total sample, 266 adopted and 59 biological children; for within-family pairs, 33 pairs of one adopted and one biological child each. Differences are in standard score units, and are adjusted for age, age2 and sex. A positive score means adopted children are higher.

388


CPI/TTS scales, F(25, 292) = .97, p = .51) the differences on the Socialization scale cannot be regarded as firmly established in this study, but they are reasonably substantial ('/3 a and lli a). It might be noted that adopted children in the previous study who were rated by their parents as being relatively low in socialization (uncontrolled, follows own urges, disregards rules) had biological mothers who more frequently endorsed MMPI items like "I do not blame a person for taking advantage of someone who lays himself open to it." Or "I don't blame anyone for trying to grab everything he can get in this world" (Loehlin et al., 1982), consistent with a genetic effect in this domain. Discussion Together with Scarr et al.'s two studies in Minnesota and the earlier Texas adoption study, the results of this study make it quite clear that in the absence of shared genes very little resemblance in personality is produced by the common environment that family members share, or by such similarity-producing mechanisms as imitation or identification. At least this is so for personality as measured by the scales of typical personality inventories. The first Minnesota study and the previous Texas study suffered from the handicaps that the children involved were fairly young and were measured with different instruments than those used with the parents. The present study confirms the finding of the second Minnesota study that the same result is obtained with late-adolescent children measured by the same questionnaire as the parents. The present study also extends this finding into young adulthood. The resemblance produced by environmental mechanisms is not, however, quite zero. The present study agrees with the preceding studies in finding low average adoptive correlations on personality scales, of the order of .05 or so, which would seem to represent some contribution of environmental factors (or at least shared response sets) in creating resemblance among biologically unrelated family members on personality scales. Now these studies do not encompass a very extreme range of environments; for example, we may be fairly confident that few

of these families seriously neglected or abused their children. Thus the studies do not speak to the effect on personality of environments beyond the normal range. But the families in these studies do display a diversity of parental personalities that is essentially as great as that in the samples on which the questionnaires were standardized (there is some restriction of range for psychopathological traits [Loehlin etal., 1982]). We must suppose there also to be familyto-family differences in the parents' childrearing philosophies, in the warmth and closeness of the homes, in the quality and character of schools attended by the children, in the occupational, economic, and educational status of the parents. Although these variables may sometimes have differed for different children within a family, one would expect them to differ much less within than across families and therefore to contribute to personality resemblance among children growing up in the same families, if they contribute importantly to personality development at all. Furthermore, parents and children should be less correlated for such variables than siblings, at least insofar as we are comparing the parents' own childhood environments with those of their children. But the resemblances of biologically unrelated siblings were no greater than those of biologically unrelated parents and children. One can only conclude that variables of the sort mentioned above must carry rather little weight in accounting for personality variation, at least within the normal range. Well, is it then the genes? On the basis of the present study alone one would need to be fairly cautious in drawing conclusions on this point, owing to the considerably smaller numbers of biological than adoptive children in the sample. But the results of the present study are reasonably consistent with those of the second Minnesota study and studies of ordinary families in suggesting that biologically related pairs of individuals, whether parents and children or siblings, resemble each other to the modest degree represented by an average correlation of about .15 on personality inventory scales. If about .05 of this can be attributed to shared environment, that leaves .10 for the contribution of shared


genes. This would seem to indicate that additive genetic effects, at any rate, make a fairly modest total contribution to personality, because the total effect should be about twice the shared effect, or about .20. What about nonadditive genetic effects? Suppose that personality depends mostly not on single genes, but rather on unique gene configurations that tend not be be transmitted intact from parents to their children? This alternative may need to be given some weight because it could account for the fact that studies comparing monozygotic and dizygotic twins tend to give larger estimates for the effects of genes on personality than do adoption studies. Monozygotic twins share gene configurations as well as genes. Lykken (1982) has proposed the concept of emergenesis to cover such nonadditive genetic effects and suggested that they may account for some of the striking resemblances observed in studies of separated identical twins. Personality theorists such as Eysenck (1982) or Buss and Plomin (1975), who have emphasized genetic effects on personality and temperament, have based their conclusions mostly on twin studies. Because they have typically been more concerned with the degree of genetic determination of behavior than with the extent to which it is transmitted genetically from parent to child, the use of twin data is quite appropriate. Nevertheless, it underlines the importance of a fuller analysis of the nonadditive effects of genes on temperament and personality. The alternative hypothesis to unique genetic configurations is idiosyncratic experiences. It seems clear that these must play a considerable role even if one makes a maximum allowance for nonadditive genetic effects. Monozygotic twins, who share all genetic effects, and more environment than siblings of different ages and sexes, correlate on an average only around .48 on personality inventory scales (Loehlin, 1977, Table 1). The remaining .52 must be due to idiosyncratic environment and errors of measurement. Of course none of this says that we have a very clear idea of what this idiosyncratic environment is: how much of it is chance biochemical accidents in early development, say, and how much is one's unique relationships with other people. Careful developmental studies of personality may

389

help. The apparent stability of the relative effects of shared environmental variables from age 7 or so into adulthood, as shown by the adoption studies, might suggest that the idiosyncratic environmental events have their maximum impact early in life. But one can hardly make a strong inference here. Finally, what about possible gene-environment interaction? The earlier study gave some evidence of this occurring in the emotional adjustment domain, with the better adjustment of the children of the poorly adjusted unwed mothers. The present study suggests that in a sample of older adopted children this is no longer the case. This result might be given several interpretations. First, it might simply be viewed as a failure of replication—the interaction was a fortuitous characteristic of the first sample which was not found in a new one, for whatever reason. Second, it might represent a characteristic maturational change in the adopted children, something that occurs around the time of adolescence to shift their behavior from relatively well adjusted to problem-prone. On this hypothesis their mothers' lives could well have taken a similar course. A third possibility is the one previously discussed; namely, that these children were highly sensitive to their environments, and responded well to the warmth of their adoptive homes, but are now having difficulties as they attempt to come to terms with a wider and less consistently supportive world. On this hypothesis, no close parallel with their mothers' life histories need be expected. The latter might well, for example, have taken an adverse course from the beginning, if the mothers' early environments had been less than benign. A follow-up study of the individuals in the first sample, which is now underway, should help resolve some of these questions, though it will not resolve all of them. In the meantime, it should be emphasized that the major thrust of these studies is not that the genes are all-important in shaping the personalities of children, although they do appear to make a significant contribution. The major thrust is that shared environment contributes so little. This suggests that something else—configural genetic effects, idiosyncratic experiences, measurement problems—

390


carries the main share of the action. It would be nice to know which, how much, and how. References Buss, A. H., & Plomin, R. (1975). A temperament theory of personality development. New \ork: Wiley. Cattell, R. B. (1973). Personality and mood by questionnaire. San Francisco: Jossey-Bass. Crook, M. N. (1937). Intra-family relationship in personality test performance. Psychological Record, 1, 479502. Dixon, L. K., & Johnson, R. C. (1980). The roots of individuality. Monterey, CA: Brooks/Cole.

Eysenck, H. J. (1982). Personality, genetics, and behavior. New York: Praeger.

Goldberg, L. R., & Rorer, L. G. (1964). Test-retest item statistics for the California Psychological Inventory. Oregon Research Institute Research Monographs, 4, (1). Gough, H. B. (1964). CPI manual (rev. ed.). Palo Alto, CA: Consulting Psychologists Press. Horn, J. M., Loehlin, }. C., & Willerman, L. (1982). Aspects of the inheritance of intellectual abilities. Behavior Genetics, 12, 479-516. Loehlin, J. C. (1977). Psychological genetics, from the study of human behavior. In R. B. Cattell & R. M.

Dreger (Eds.), Handbook of modern personality theory (pp. 329-347). New York: Halsted Press. Loehlin, J. C, Horn, J. M., & Willerman, L. (1981). Personality resemblance in adoptive families. Behavior Genetics, 11, 309-330. Loehlin, J. C., & Nichols, R. C. (1976). Heredity, environment, and personality. Austin: University of Texas Press. Loehlin, J. C., Willerman, L., & Horn, J, M. (1982). Personality resemblances between unwed mothers and their adopted-away offspring. Journal of Personality and Social Psychology, 42, 1089-1099. Lykken, D. T. (1982). Research with twins: The concept of emergenesis. Psychophysiology, 19, 361-373. Rowe, D. C., & Plomin, R. (1981). The importance of nonshared (E,) environmental influences in behavioral development. Developmental Psychology, 17, 517-531. Scarr, S., Webber, P. L., Weinberg, R. A., & Wittig, M. A. (1981). Personality resemblance among adolescents and their parents in biologically related and adoptive families. Journal of Personality and Social Psychology, 40, 885-898. Thurstone, L. L. (1953). Examiner manual for the Thurstone Temperament Schedule. (2nd ed.) Chicago: Science Research Associates. Woodruff, D. S., & Birren, J. E. (1972). Age changes and cohort differences in personality. Developmental Psychology, 6, 252-259.

Appendix Table A Means and Standard Deviations of CPI Scales for Male Groups, Compared to CPI Norms Adoptive sons

Biological sons

Scale

M

SD

M

SD

M

SD

M

SD

Dominance Capacity for Status Sociability Social Presence Self-Acceptance Sense of Well-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency PsychologicalMindedness Flexibility Femininity Number

27.0 17.3 23.5 36.6 22.1 33.0 24.4 33.3 21.6 17.6 12.7 25.7

6.3 4.2 5.3 6.0 3.5 5.8 5.8 7.0 8.7 5.0 5.8 1.8

27.0 17.4 23.6 35.9 21.6 33.8 25.4 35.9 23.2 18.4 12.8 26.0

7.5 3.8 5.1 6.3 3.6 4.1 5.7 4.8 7.3 4.9 4.7 1.7

30.2 19.0 23.5 33.1 20.4 37.9 31.5 38.7 32.9 23.1 18.9 26.8

6.0 4.1 5.4 6.2 3.7 3.8 4.7 4.6 6.7 4.6 5.7 1.3

27.0 19.3 24.5 34.0 19.3 37.5 31.0 36.5 31.0 23.0 20.0 25.2

5.1 3.8 5.0 5.3 3.7 4.0 5.0 5.6 7.4 4.8 6.1 2.2

22.6

5.5

24.0

3.5

28.5

4.3

27.5

4.6

16.5 35.2

4.5 5.8

17.3 35.7

4.4 5.4

20.2 38.4

3.9 5.1

18.7 39.3

4.2 4.7

10.7

2.6 3.8 3.8

9.9 9.0

3.0 3.2 3.4

12.0

2.3 4.0 3.3

11.0

2.8

9.0

3.5 3.9

9.3 15.6

118

15.5

29

Fathers

8.1 16.6

196

Male norms

Note. Norms estimated from standard score conversion table in CPI Manual (Gough, 1964).

16.3 6000+

391

PERSONALITY RESEMBLANCES IN ADOPTIVE FAMILIES Appendix Table B Means and Standard Deviations ofCPI Scales for Female Groups, Compared to CPI Norms Biological daughters

Adoptive daughters

Mothers

Female norms

Scale

M

SD

M

SD

M

SD

M

SD

Dominance Capacity for Status Sociability Social Presence Self-Acceptance Sense of Well-Being Responsibility Socialization Self-Control Tolerance Good Impression Communality Achievement via Conformance Achievement via Independence Intellectual Efficiency Psychological-Mindedness Flexibility Femininity Number

26.4 17.5 23.4 34.5 21.8 32.2 27.3 36.1 24.3 19.2 13.1 26.2

6.7 4.6 6.2 6.1 4.0 6.3 5.8 6.9 8.4 5.4 5.7 1.6

29.0 18.2 24.3 34.8 21.2 34.7 30.1 38.5 27.9 21.9 14.4 26.5

6.8 4.0 5.2 5.2 3.9 5.4 5.9 5.2 8.2 5.8 5.4 1.7

27.9 18.7 22.5 30.6 20.1 36.4 33.7 40.7 34.3 22.7 18.3 26.7

6.5 3.8 5.2 6.2 3.7 4.2 3.6 4.2 6.2 3.9 5.6 1.4

27.0 20.0 24.5 34.0 20.0 37.5 32.0 39.5 32.0 23.0 20.0 25.8

5.6 3.6 4.7 5.6 3.6 4.4 4.7 5.3 7.2 4.3 6.1 2.2

24.3

5.5

26.0

5.4

29.4

4.0

28.0

4.4

18.0 35.3

4.2 6.2 2.7 3.4 3.4

20.6 37.4 11.3

3.5 5.0 2.9 2.9 3.0

21.5 38.1 11.2

3.4 4.9 2.6 3.5 2.8

19.0 39.0 11.0

4.0 4.9 2.8 3.5 3.5

9.8 9.5 23.2

9.8 23.3

148

8.4 24.7

30

9.0 23.0

202

7000+

Note. Norms estimated from standard score conversion table in CPI Manual (Gough, 1964).

Appendix Table C Means and Standard Deviations of TTS Scales for Male Groups, Compared to TTS Norms Adoptive sons

Biological sons

Scale

M

SD

M

-SD

M

SD

M

SD

Active Vigorous Impulsive Dominant Stable Sociable Reflective Number

11.2 12.0 11.2

3.3 4.0 3.6 5.2 3.6 4.3 3.6

11.2 11.1 10.9

3.7 2.9 3.3 4.9 3.0 3.8 3.6

10.5 11.2 10.4

3.9 3.4 3.5 5.4 3.7 4.0 3.6

10.2 11.9 11.8

3.2 3.8 3.2 5.2 3.8 3.8 3.3

8.9 9.4 10.0

8.5 127

8.5 9.8 9.7 8.1

30

Fathers

9.9 12.3 11.4

9.3

Note. Norms estimated from percentiles in TTS Manual (Thurstone, 1953).

206

Male norms

9.6 10.3 12.8

8.5 1234

392


Appendix Table D Means and Standard Deviations of TTS Scales for Female Groups, Compared to TTS Norms Adoptive daughters

Biological daughters

Mothers

Female norms

Scale

M

SD

M

SD

M

SD

M

SD

Active Vigorous Impulsive Dominant Stable Sociable Reflective Number

11.1

3.3 3.6 3.4 5.0 3.5 4.0 3.6

11.0

3.5 3.6 3.4 5.5 3.8 4.1 3.7

10.1

3.6 3.1 3.3 5.0 3.5 3.7 3.2

9.9 7.0

3.2 3.4 3.4 4.6 4.0 3.6 3.3

7.2

11.2

9.2 8.8 11.9

7.3

156

7.6 11.4

9.7 10.2 11.7

7.6

5.8 8.8 8.6 10.5 12.3

9.0

30

213

12.0

9.2 10.2 14.0

8.0

657

Note. Norms estimated from percentiles in TTS Manual (Thurstone, 1953).

Received April 11, 1983 Revision received September 6, 1983

Manuscripts Accepted for Publication in the Section Personality Processes and Individual Differences Attribution Style and the Type A Coronary-Prone Behavior Pattern. Michael J. Strube (Department of Psychology, Washington University, St. Louis, Missouri 63130). Relinquishment of Control and the Type A Behavior Pattern: The Role of Performance Evaluation. Michael J. Strube (Department of Psychology, Washington University, St. Louis, Missouri 63130), Jane M. Berry, and Stephanie Moergen. Separation-Individuation and the Intimacy Capacity in College Women. Ellen M. Levitz-Jones and Jacob L. Orlofsky (Department of Psychology, University of Missouri-St. Louis, St. Louis, Missouri 63121). The Effect of Alcoholic Intoxication on the Appreciation of Different Types of Humor. James B. Weaver (Institute for Communication, Indiana University, Bloomington, Indiana 47405), Jonathan L. Masland, Shahin Kharazmi, and Dolf Zillman. Value Correlates of Preventive Health Behavior. Connie M. Kristiansen (Department of Psychology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1). Life Stress and Health: Personality, Coping, and Family Support in Stress Resistance. Charles J. Holahan (Sociol Ecology Laboratory, Department of Psychiatry TD 114, Stanford University School of Medicine, Stanford, California 94305), and Rudolf H. Moos. Extraversion, Social Cognition, and the Salience of Aversiveness in Social Encounters. William G. Graziano (Department of Psychology, University of Georgia, Athens, Georgia 30602), Alice Bernstein Feldesman, and Donald F. Rahe. Self-Enhancement, Self-Assessment, and Self-Evaluative Task Choice. Michael J. Strube (Department of Psychology, Washington University, St. Louis, Missouri 63130) and Laurie A. Roemmele. Factors Governing the Effective Remediation of Negative Affect and Its Cognitive and Behavioral Consequences. R. Christopher Barden (Public Policy Studies, Vanderbilt University, Nashville, Tennessee 37212), Judy Garver, Burt Leiman, Martin E. Ford, and John C. Masters. Personal Efficacy, External Locus of Control and Perceived Contingency of Parental Reinforcement Among Depressed, Paranoid, and Normal Subjects. Michael Rosenbaum (Department of Psychology, Tel Aviv University, Tel Aviv, Israel) and Dov Hadari. Depression and Preference for Self-Focusing Stimuli Following Success and Failure. Tom Pyszczynski (Department of Psychology, University of North Carolina, Chapel Hill, North Carolina 27514) and Jeff Greenberg. Cognitive/Affective Reactions in the Improvement of Self-Esteem: When Thoughts and Feelings Make a Difference. Susan M. Anderson (Department of Psychology, University of California, Santa Barbara, California 93106) and Marirosa Williams. Test Anxiety and Visual Vigilance. Russell G. Geen (Department of Psychology, University of Missouri, Columbia, Missouri 65211). Moderator Variables and Different Types of Predictability: Do You Have a Match? William E. Wymer (Department of Psychology, University of South Florida, Tampa, Florida 33620) and Louis A. Penner.