A COMMENT ON ESTIMATING W.A.I.S. I& 95

centile. Shaw’s difficulty is clearly that his WAIS full scale I@, already corrected for age, are correlated with Progressive Matrices score with no such age allowance.

It would appear that Progressive Matrices scores give a very useful measure of non-verbal performance. This conclusion is evident not only in high correlations with measures such as the Wechsler scales, but in factorial studies, and in occupa- tional and educational selection. In fact, it is doubtful how justified is Shaw’s state- ment that the Progressive Matrices can be used “when only an I& estimate is re- quired”. It could be argued that the Matrices, being a relatively “pure” measure, is preferable to the omnibus type of measure such as the Wechsler, with its rather short subtests.

A better way of calculating I& equivalents for the Progressive Matrices is by using the percentile points for each age, and transforming these into I& equivalents in terms of the known percentile points of the normal distribution curve. If the I& scale used is one with a SD of 15, and age norms are calculated, this gives a scale directly comparable with the Wechsler and one more useful and valid than Shaw’s. The writer has published ( l ) such a table for subnormals, using the Coloured Pro- gressive Matrices, after an initial correlation with the WAIS. Other tables, con- cerning children and normally intelligent adults, can be found in a subsequent paper (2).

REFERENCES 1.

2.

3.

4.

OFIME, J. E. The Coloured Progressive Matrices as a measure of intellectual subnormality.

ORME, J. E. Hypothet,ically true norms for the Progressive Matrices test. Human Deuelop-

RAVEN, J. C . Guide lo the Standard Progressive Matrices, sets A , B, C , D , and E. London: H. K.

SHAW, DALE J. Estimating W. A. I. S. I& from Progressive Matrices Scores. J. clan. Psychol.,

Brit. J . Med. Psyehol., 1961,.94, 291-292.

ment, 1966, 9, 222230.

Lewis, 1960.

1967, 23, 184-18.5.

WAIS PA PERFORMANCE AND PARTICIPATION I N EXTRACURRICULAR ACTIVITIES*

THOMAS SCHILL, MALCOLM KAHN AND THOMAS MEUHLEMAN

Southern Illinois [Tniversily

In using the Wechsler scales to asses person- ality characteristics, clinicians generally assume that the Picture Arrangement subtest (PA) is a measure of social intelligence. Schafer(2* p. 4 7 )

for instance, attributes the hjgh PA score of& forind for Ss labeled narc!ss?tic character d!s- orders to their characteristically facile social anticipations. Psychopathic character disorders frequently have a conspicuously high PA score, especially the “shrewd schemer” who can quickly size up a social situation and manipulate i t for

What is implied here is that high PA as com- pared to low PA Ss are more socially oriented and also more seilvitive and aware in interpersonal situations. In support, of this vjew, Schill(’’ has recently found that MMPI social introverts de- monstrate greater impairment on PA than social extraverts. This study attempts to relate PA performance to a more behaviorally relevant cri- terion of sociability, the Ss’ participation in high school and college extracurricular activit,ies.

his own erld(1, P. 670; 2 . P. 64; 4 , P. 1761.

METHOD Ss were 77 male and 55 female undergraduate

volunteers. The WAIS PA and Vocabulary (V) subtests were individually administered to each student. The S was also asked to fill out a de- tailed information blank which included items regarding participation in high school and college extracurricular activities and approximate size of school. The activities were grouped into five categories: Debate, Dramatics, Music and Art, Athletics, and Student Government. A score of 1 was assigned to each area regardleas of t.he amount of participation in that area.

RESULTS Ss with PA scale scores of 10 and above (Males

= 34, Females = 23) and those with scores of

*This investigation was supported by a Grant from the Psychiatric Training and Research Fund of the Illinois Department of Mental Health.

96 THOMAS SCHILL, MALCOLM KAHN AND THOMAS MEUHLEMAN

9 and below (Males = 43, Females = 32) were compared regarding number of extracurricular activities engaged in. The high P A group was found to have participated in signiiicantly more extracurricular activities than the low PA group (F = 14.81, 1/130 df, P = < .001; mean num- ber of activities for high PA = 2.60, for low PA

Smce Ss scoring high on PA should also have been more intelligent, it was necessary to de- termine whether this difference for extrscurricu- lar activities would persist after differences in intelligence were taken into account. Therefore, an analysis of co-variance was performed using Ss’ vocabuh .scores as an estimate of their in- telligence. T ! resulted in an F.of 11.6 with 1 and 129 df, P < .001. This in&cates that the differences between the PA groups on extra- curricular activities could not be accounted for by Uerences in mean level of vocabulary scores.

SUMMARY Ss scoring high and low on the WAIS Picture

= !.97).

Arrangement subtest were compared regarding their participation in high school and college extracurricular activities. Consistent with clin- ical notions, high P A Ss were found to engage in significantly more activities, which difference persisted even after differences in intelligence were taken into account.

REFERENCES 1. ANDERSON, H. and ANDERSON, G. A n Intro- duction to Projective Techniques. Englewood Cliffs, New Jersey: Prentice-Hall, 1951.

2. SCHAFER, R. The Clinical Applicalion of Psychological Tests. New York: International Universities Press, 1948.

3. SCHILL, T. The effects of MMPI social intro- version on WAIS PA performance. J . clin. Psychol., 1966, 22, 72-74.

The Measurement and A p praisal of Adult Intelligaee (4th Ed.). Balti- more: Williams and Williams, 1958.

4. WECHSLER, D.

THE INFLUENCE OF AGE ON TRAIL MAKING TEST PERFORMANCE ANN D. M. DAVIES

Medical Research Council, Unit for Research on Occupational Aspects of Ageing, Department of Psychology, University of Liverpool, England

PROBLEM Reitan’s Trail Making test (TMT) has been used as an index of brain damage

(7, 8, 9 ) . Reitan, using a relatively young sample of heterogeneous brain damaged (BD) patients and hospitalized controls found that the test gave good discrimination with approximately equal numbers of false positives and false negatives. Other authors(2* 5, 6 , 11), however,report that the test tends to throw up false positives, that is, it calls brain damaged those who are not. This study examines the effects of age and of brain damage on TMT performance and suggests that the diagnostic efficiency of the test depends, in part, on the ages of the samples used.

STUDY I Subjects. The TMT (Parts A and B) was given in accordance with Reitan’s(’)

instructions to 540 normal Ss from the British Medical Research Councli’s volunteer panel in Liverpool. The panel is described by Heron(‘) and consists of 50 men and 40 women in decade age groups from 20s to 70s.

In Part A of the test, S connects a sequence of scattered circles numbered 1, 2, 3 . , . 25; in Part B, letters, too, are included, 1 - A - 2 - B . . . L - 13. The score is time taken for each part, transformed to itsitan’s ordinal (credit) scale. The scale ranges from 1 (slow) to 10 (fast).

Results. Table 1 shows percentile points within age decades calculated from the raw scores of the 540 Ss for Part A and for Part B. In any decade there is no significant difference between the mean scores of men and women. Combining all age groups, however, men appear to be slightly quicker. (Part A, t = 1.25, p > .05; Part B, t = 2.20, p < .05).