Table Of ContentINTELLIGENCE AND MENTAL ILLNESS
A Thesis
Submitted to the Faculty
of
Purdue University
by
Charles F. Mason
In Partial Fulfillment of the
Requirements for the Degree
of
Doctor of Philosophy
August, 1950
^ 2■'hSC,
P 1R D U E UNIVERSITY
THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MX SUPERVISION
by Charles P. Mason
INTELLIGENCE AND MENTAL ILLNESS
entitled
COMPLIES WITH THE UNIVERSITY REGULATIONS ON GRADUATION THESES
AND IS APPROVED BY ME AS FULFILLING THIS PART OP THE REQUIREMENTS
FOR THE DEGREE OF
Doctor of Philosophy
\ o $ L T n .
Professor in Charge of Thesis
G < 2 - n t. Head of School or Department
TO THE LIBRARIAN:-----
*S-
THIS THESIS IS NOT TO BE REGARDED AS CONTIDENTIAL.
PBOFKSSOB nr CBAXOB
GBAD. SCHOOL FORM B—3-40—1H
ACKNOWLEDGMENTS
In carrying out this study I have relied heavily on
the cooperation and aid of several organizations and in
dividuals.
The Veterans Administration and the personnel of the
hospital at Marion, Indiana have been very cooperative
throughout. Members of the Registrar Division have been
of great aid in the collection of data. My colleagues
on the Psychology staff have taken an interest in the
project in all its phases which has been extremely helpful.
The staff of the Office of the Adjutant General has
been very helpful in providing necessary information. The
Records Administration Center was always prompt in provid
ing the basic data for the study.
The members of my committee and especially Dr.
John M. Hadley, the chairman, have assisted me greatly
with advice and criticism.
Acknowledgment is given to these persons for their
services for which I am very grateful. This is their
study as much as my own.
C.F.M*
VITA
Academic.
AB, The State University of Iowa, December 194-2*
Psychology major.
MS, Psychology, Purdue U n iv ersity , August 194-7*
In d u strial Psychology major*
Experience in Psychology.
Graduate assistant, General and Experimental
Psychology, Purdue University, September 194-& to
June 194-7*
Psychologist, interne, Veterans Administration
Training Progran in Clinical Psychology, September
194-7 bo September 1950* Internship at Billings
VA Hospital, Indianapolis, VA Mental Hygiene Clinic,
Indianapolis, and VA Hospital, Marion, Indiana; in
cooperation with Purdue University.
Instructor, General Psychology, Indiana University
Extension, Septanber 194-9 to June 1950*
Organizations.
American Psychological Association
Sigma Xi
Midwest Psychological Association
TABLE OF CONTENTS
Page
ABSTRACT ...................................................................... *
INTRODUCTION * • 1
Purpose • •............. . . . . ............................................... 1
Intelligence and Mental Health ...................... 1
Intelligence and Type of Mental Illness .................. 3
Experimental Design ........................................... I4.
STATEMENT OP THE PRO BLEM ...................................................... 8
PROCEDURE................................................................... 12
Control Distribution ••••................................................................. 12
Requirements of the Sample . . . ............ II4-
Drawing the Sample .................... 15
Statistical Procedures ...................................................... 17
The Question of Pre-illness Intelligence . ........ 18
RESULTS ......................................................................... 21
Patients versus Soldiers •...•••.•............................. 21
Breakdown by Diagnostic Categories ..................... 21
DISCUSSION ................................................................................... 27
The Causal Interpretation ................... 29
The Concomitant Interpretation ............................. 29
Emphasis on Diagnosis Rather than Symptoms ....... 31
SUMMARY AND CONCLUSIONS ..................................................... 33
APPENDIX. TABLES 5 THROUGH 15 ......................................... 3^
BIBLIOGRAPHY.. ................................................... ij.6
SUPPLEMENTARY BIBLIOGRAPHY . . ..................................................... ij.8
M sm
LISTS OP TABLES AND FIGURES
List of Tables
able Pag®
1* Standard score equivalents of Army grades . ... 10
2* Distributions of control data • *................*............ 13
3* Percentage distributions of AGGT scores for
various diagnostic categories . . . . . . . . . . . . . 23
I4.* Results of chi-square comparisons for ail
patients and for diagnostic breakdowns • ••* 2q.
5* Home states of 200 Marion hospital patients .. 35
6. Correlation data, pre-hospital service vs*
total serviee ............................ 3&
7* A nalysis o f variance, length, o f serv ice vs*
AGCT....................................................................... 37
8 * Chi-square table, patients vs. controls *••••» 33
9* Chi-square table, schizophrenics vs. controls 39
10* Chi-square table, non-schizophrenics vs*
controls ................................. ii-0
11* Chi-square table, hebephrenies and catatonies
vs* controls .......... ip-
12* Chi-square table, psychoneurotics vs. controls ip
13* Chi-square ta b le , paranoid sch izop h ren ics,
character and behavior disorders vs. con
trols ...................... if3
li|.* Chi-square table, simple schizophrenics vs*
controls * * * ....................................... •». • • • ip
15* Ghi-square ta b le, other sch izop h ren ics,
chronic alcoholics, manie-depress!ves vs*
controls . . . . . . . . . . . . . , .. * . . ...... ... - 45
List of Figures
1* Graphic representation of AGGT distributions
for con trols and p a tien ts * . . • • • • • . . . . . . * • • 22
ABSTRACT
Mason, Charles P. INTELLIGENCE AND MENTAL ILLNESS,
August 1950, 53 15 ta b le s, 1 fig u re, 24 t it le s in
the bibliography.
The question of relationship between intelligence and
mental health is extremely popular both in scientific
literature and non-scientific thought. Published evidence
and opinion on the topic shows disagreement. This study
was designed to collect further evidence bearing on the
topic.
A representative sample of functionally diagnosed,
male, World War II, Army veterans was drawn from the files
of the Veterans Administration neuropsychiatric hospital
at Marion, Indiana. Army General Classification Test
scores of these subjects were obtained from the Army*
Analysis of the data led to the following conclusions:
1. The data showed no evidence of a definite relation
ship between AGCT intelligence and adjustment.
2. A relationship was found between AGCT Intelligence
and type of mental illness*
a* Schizophrenics, with the exception of
paranoids, tend to have scored low on the AGCT*
b* Manic-depressives tend to have scored high
on the AGGT.
INTELLIGENCE AND MENTAL ILLNESS
INTRODUCTION
Purpose* The purpose of the present study is three
fold: (1) to gather evidence bearing on the question of
whether or not there is relationship between "intelligence"
and "mental illness;" (2) if any evidence of such relation
ship is found, to investigate it as to extent and nature;
(3) to investigate for systematic differences in "intelli
gence" among various diagnostic groups among the "mentally
ill."
Intelligence and mental health. The question of re
lationship between intelligence and mental health as two
aspects of personality is extremely popular both in
scientific literature and non-scientific thought. There
is, for example, the age old proposition of a kinship be
tween genius and insanity. Witty and Lehman A 23) have dis
cussed the evidence bearing on this question in detail.
On the other hand, this investigator has been struck by
the failure of a large percentage of mental hospital
patients, as well as other lay groups, to differentiate
between insanity and stupidity.
After considerable discussion of the question and a
review of the literature on the subject, it appears to
this investigator that casual and experimental hypotheses
usually embody one or both of two general principles.
The first of these general principles is designated by
Chassell (1) as "the principle of the mutual relationship
of desirable qualities." An application of this principle
to the question at hand is made by Lorge (12) as follows:
Intelligence is a positive trait and good adjustment is
a positive trait. It seems reasonable to infer that
whenever personality is measured in terms of goodness
of adjustment or of integration a positive correlation
will be the result.
The second of these two general principles is that "the
maximum is not the optimum." Hollingworth (8 ) may be cited
as representing this position:
In studying the eccentric Influence of deviating in
telligence, at both extremes, the concept arises of
an optimal intelligence /Ser italics^ that is neither
minimum nor maximum. The problem for social psychology
is to fix the limits of this optimum in texms of IQ.
It is a situation in which there can be either too
much or too little of a good thing ("good," that is,
for interaction with other persons, and hence for per
sonality adjustment).
Prom observations recorded in the literature to this
time, the hypothesis may be offered that optimal in
telligence, in the sense just referred to, lies above
average, rather than at or below average, and centers
approximately 3 to 5 EE above the mean--that is, be
tween 130 and 150 IQ (Stanford Binet). Within this
range, the person comprehends more clearly, but not
too much more clearly, than the majority of his fellow
men, and can thus get himself accepted as a supervisor
and leader of human affairs generally, with accompany
ing emoluments and privileges. His vocabulary, his
Interests, and his hopes have, at this point, still
enough in common ^Ker italics/ with his contemporaries
to enable and warrant cooperation. Beyond this range,
however, mutual rejection begins to appear between the
deviate and nearly all his contemporaries.
The experimental evidence bearing on this subject is
conflicting in many respects. Lorge (12) has reviewed the
literature on the general relationship between intelligence
and various measures or estimates of personality. In an
analysis of some 200 correlation coefficients he found a
range of from -.J|9 to .70 with a median of *0ij.. Of these
findings he says that the range is so "extraordinary that
anybody can make any statement." Hollingworth and Bust (9)
have found very intelligent college students to be "much
less neurotic" than controls. Wrenn, Ferguson, and Kennedy
(2if) studied junior college students and found that "ex
tremes of intelligence do not seem to be associated with
differences in emotional stability." Neustatter (13)
studied children of different Income groups and found some
what less "nervousness" among the poor than among the well-
to-do families. If the usual relationship between socio
economic level and intelligence discussed by Goodenough (7 )
applies to Neustatter’s samples we may think of this study
as bearing on the question at hand.
Intelligence and type of mental illness. Most of the
studies relevent to the relationship between intelligence
and type of mental illness have been of a sociological
nature. Some measure of socio-economic level has been
studied rather than any direct measure of intelligence.
An example of this type of study is the work of Hyde and
Kingsley (10). They found that: "The ^rejectio^T* rate
for psychoneurosis showed no consistent variation with
socioeconomic level; only the intermediate level
