AN EXTRAVERSION SCALE FOR THE MMPI 159

and the test scores was .35 indicating external confirmation of the trait measured in questionnaire form. The face validity of the items is quite obvious and they tend to describe the stereotype of an extravert as some one who is socially aggressive, full of energy and active, has definite ideas and is sure of them, and likes to be with people.

As with most MMPI scales there is item overlap. Items 171 and 267 occur on scales Ex, MA, and SY. Items 292, 304, 353, 409, 448, 449, 546 and 552 occur on both scales Ex and SY. ltems 59, 180, 181, 222, 268, and 271 occur on scales MA and Ex, The remaining items occur only on one of these three scales as follows: 38 on MA, 12 on SY, and 22 on Ex. Although according to Kassebaum’s analysis the Ex scale should be directly opposite Welsh’s R scale and negatively correlated with it there is only one item that occurs in both these scales, 447, which is scored op- positely for the two scales.

SUMMARY This study reports the standardization of a new MMPI Extraversion-Intro-

version scale (Ex). With this extraversion scale available, MMPI users can measure this important personality dimension without also measuring aspects of pathology or health. If they wish to use the conceptual scheme suggested by Kassebaum, they have available scales to measure each main factor and fusion factor.

REFERENCES 1. EYSENCK, H. J. The structure of human personality. New York: Wiley, 1953. 2. KASSEBAUM, G. G., COUCH, A. S., and SLATEIR, P. E. The factorial dimensions of the MMPI. J . consult. Psychol., 1959, 93, 226-236.

RACIAL DIFFERENCES ON THE MMPI CHRISTINE MILLER AND CLARA WERTZ AND SARAH COUNTS’

Oakland V A Mental Hygiene Clinic Napa (Cahf.) State Hospital

PROBLEM AND METHOD The increasing use of the MMPI with white and negro patients has raised the

question of applying white norms to negro groups. Fry(1) found no significant differences in MMPI scores between negro and white prisoners. Hokanson and Caldenc2) found negroes to be significantly higher on PD, MF, Sc, MA, L, and F in a VA tuberculosis hospital setting. They conclude that “negroes tend to show less concern over conventional social mores ; demonstrate a greater emotional vigor and buoyancy; are more prone to act on their ideas and impulses; manifest more of what are considered to be bizarre or unusual thoughts and behavior; and exhibit a more feminine interest pattern.”

The present writers have collected MMPI records from 100 negroes and 100 whites who applied for treatment a t a VA mental hygiene clinic. No significant differ- ences between negroes and whites were found in age, employment status, or educa- tion. Both patient samples were well above average for the general population in education. In occupational level, however, the whites and negroes had markedly different distributions, 39% of the negroes falling in the lowest category, unskilled labor, while only 8% of the whites were in this group.

RESULTS Table 1 gives the MMPI findings for the two groups. Of more importance than

these differences, however, are analyses of variance comparing the present data with

1Previously at the Oakland Mental Hygiene Clinic. For invaluable assistance in various stages of this study the authors are indebted to Read D. Tuddenham.

160

-

Scale

L F K Hs D HY

MF

sc MA A R

P D

PA PT

CHRISTINE MILLER, CLARA WERTZ AND SARAH COUNTS

TABLE 1. MMPI T SCORES

Negro Mean SD

51.1 8 .4 63.2 16.4 51.0 8 .8 80.5 19.8 80.7 16.0 74.2 12.0 66.6 14.5 58.6 9.4 58.5 14.6 ii .O 17.2 74.0 22.1 62.4 12.3 53.0 9.2 51.1 6.8

White Mean SD

47.2 6.9 61.1 11.8 50.3 8.6 74.9 14.7 79.4 16.4 72.1 11.2 68.4 12.9 64.4 11.1 59.6 11.6 73 .O 15.1 69.1 16.3 58.4 12.3 54.7 5 .O 50.6 8.7

CR P

3.6 ,001

2.2 .05

1.3 .20

4.1 .001

<1 ns < I ns

< I ns

<I ns

<1 na (1 ns .~

1.8 . lo 2.3 .02 1.6 .20

<1 ns

those of Fry(') and Hokanson and Caldenc2). Figure 1 shows the mean profiles for negroes and whites from the three institutions.

Mental Hvciena Clinic

Figure 1.

Prison

PROFILES FOR THREE INSTITUTIONS

Hs D H y Pd Mf Pa P t Sc Ma

1. B. Hospital 90

80

70

60

50

40

Table 2 gives the analyses of variance which indicate that most of the varlance is associated with affiliation with a particular kind of institution and very little is associated with membership in a racial group. Higher scores on Sc and MA were

TABLE 2. ANALYSES OF VARIANCE RESULTS, F VALUES~ - =

Scale Race Institution Interaction

HR 1.45 47.84*** 1.19 D <1.00 68.93*** 1.11 HY <1.00 54.65*** 1.95 PD (1.00 <1 .oo 5.64** MF P A PT sc M a

<1.00 <1.00 <1 .00

4.43* 14.38***

20.63***

39.56*** 13.45*** 10.57***

2.78 8.93*** 1.76 2.02 4.85'

<1.00

'Degrees of freedom: Race = 1, institution = 2, interaction = 2, error = 413, total = 418. * Significant a t the .05 level.

Signi6cant at the .01 level. *** Significant a t the .001 level. **

RACIAL DIFFERENCES ON THE MMPI 161

found in the negro group. The interaction effects found on PD, MF, and Sc are probably due to the fact that these scores were significantly higher in negroes in the tuberculosis hospital, but not in the other institutions.

SUMMARY These findings are consistent with findings in the area of measurement of in-

tellectual abilities, that social factors such as occupational level, education, etc., rather than race determine most of the variance in test scores. It would appear that rather than trying to develop appropriate norms for negro and white subjects on the MMPI, we need to evaluate the MMPI findings for social or racial groups for particular settings.

REFERENCES 1. FRY, F. D. A study of the personality traits of college students and of state prison inmates as measured by the MMPI. J . PsychoE., 1949, 28,439-449.

2. HOKANSON, J. E. and CALDEN, C. Negro-white diffcrences on the MMPI. J . d i n . PsychoZ., 1960, 16, 32-33.

THE USE O F WECHSLER INTELLIGENCE SCALES AS DIAGNOSTIC

INDETERMINATE UNILATERAL BRAIN DAMAGE* INDICATORS OF PREDOMINANT LEFT-RIGHT AND

EARL E . BALTHAZAR AND DON H. MORRISON

Caro State Hospital for Epibptics

PROBLEM This study investigated the possibility of establishing a cutting score for differ-

ences between the weighted verbal and performance scale IQ’s which could then be used as an aid to neuropathic diagnosis. The specific hypothesis tested was that with prior considerations a difference of seven points or greater between Wechsler Verbal and Performance Subtest scales would be of diagnostic value in determining left-right and indeterminately unilateralized brain damage. This hypothesis was taken from clinical observations regarding psychologica,l examinations given at Car0 State Hospital for Epileptics specifically including the WISC and Forms I and I1 of the Wechsler scales administered to a chronically organic inpatient population.

The differences between the subtest means of groups of subjects with predom- inantly left-sided, right-sided, and indeterminately unilateralized brain damage were also investigated. The purpose was to re-evaluate the findings of previous investigations(6- 9, and compare them with the chronically organic patients a t this hospital.

METHOD Subjects were 96 chronically organic patients a t the Caro State Hospital for

Epileptics who were administered Wechsler-Bellevue tests and electroencephalo- graphic examinations on a new admission basis. The criteria for selection were: (a) unequivocal evidence of organic brain damage in their medical history and general medical examination, (b) valid Wechslers, and (c) three or more electroencephalo- graphic reports. All subjects were assumed to have speech centers localized in the left hemisphere. An investigation by Goodglass and Quadfasel(4) reported that slightly over 97% of the general population have speech centers in the left hemi- sphere.

grams used in this study. T h e authors extend their appreciation to C. David Hellman for interpreting the electroencephalo-