Personality of Mice and Men

Heymans Bulletin HB-81-532-EX, State University of Groningen (RUG), 1981. by Popko P. van der Molen and Agnes A. de Graaf.

PERSONALITY OF MICE AND MEN

(Re-arranging Personality Dimensions in a Six-dimensional Adjective Space)

* The preparation of this paper has been made possible by the kind and patient support of the department of Personality Psychology of the Rijks Universiteit Groningen. For computational assistance the writers are indebted to Frank Brokken, Haring Land, Jos ten Berge and Hans Hommes.

Suggestions for improving a first and second draft were given by Jos ten Berge, Haring Land, Annemarie van der Molen, Hans van de Velde and especially by Boele de Raad. Margi Rothengatter corrected the worst mistakes in our use of the English language.

Abstract

As Brokken (1980), following Goldberg's (1977) approach, has shown, the greater part of the correlations between personality descriptive adjectives, as used in daily language, may be represented by means of a six-dimensional vector space. In this study the suggestions of Guilford & Hoepfner (1969), Cattell & Sullivan (1962) and Gorsuch (1974) amongst others, have been followed, namely that if generally agreed upon external criteria are available, a criterium rotation may render factors ( -and labels- ) to span the resulting 6-dimensional personality-adjective space in a way more convenient for experimentation and manipulation than a simple (- rotated or unrotated -) principal component solution could possibly be.

Criteria from model of personality trait dimensions and social-role dimensions and their interrelations, as derived from experimental research on animal behaviour, are used in this study to replace 6 orthogonal factors of personality descriptive adjectives by some 9 dimensions, each of which represents either a temperament trait, a social-role dimension, or some sort of skill. The resulting dimensions are correlated in many instances and can easily be fitted in a systematic theory of personality dynamics. It is argued that this finding supports the hypothesis that the major part of the most conspicuous personality dimensions in men is due to the mere fact that humans are socially living mammals.

Finally, some implications are briefly discussed which follow from applying this dynamic model of personality dimensions to human behaviour.

Introduction

This paper deals with dimensions of interindividual differences in personality or 'traits'. In traditional personality psychological research it has long been prevailent strategy to obtain basic data from individual subject scorings on tests or other variables that are a priori considered relevant for measuring 'traits'. Such a strategy is therefore ultimately bases on 'a priori's' concerning the relevance of certain sets of tests. As a consequence classical personality-psychological research has been strongly criticized, especially concerning these 'a priori's' (e.g. Mischel, 1976; Hogan e.a., 1977). In recent years, some psychologists have tried to avoid the shaky ground of these 'a priori's' by using exhaustive lists of personality-descriptive adjectives and ratings of individuals on these adjectives as basic material (Brokken, 1978; Hofstee, 1977; Goldberg, 1978). The factors resulting from factor analysis on such data can directly be interpreted by their strongest loading adjectives. In fact, such dimensions are vectors in a personality-descriptive adjective-space.

(Somewhat similar approaches have been applied before. Cattell's 16PF (personality factors) were ultimately based on reduction of an exhaustive set of trait names too (Allport and Odbert, 1936; Cattell e.a., 1970; Buss & Poley, 1976, pp. 71-77). In the present study it is prefered to deal directly with a primary, exhaustive and unreduced adjective space, rather than with a third- or fourth- degree derivate of it, especially since computational facilities for handling such enormous sets of data have recently become available.)

Having decided that a particular n-dimensional euclidian space is a proper representation of the considered set of data, another problem arises. The problem of determining which position of personality factors is most convenient. Guilford & Hoepfner (1969) remark: "It should be agreed that the aim of those who apply factor analysis for the purpose of discovering scientific constructs in psychology should be to achieve psychological significant factors, which can be replicated, which fit into systematic psychological theory, and which can be investigated meaningfully by other methods. Only in this way can there be general unambiguous communicability that science requires."

When dealing with a general and rather exhaustive trait space, generally agreed upon external criteria to determine where to put our labels of reference are mostly not available. Therefore internal criteria are used such as. e.g., varimax rotation of principal components. But, as Guilford (1975) states: "It is probably commonly known that the most disturbing deficiency of factor analysis is its indeterminancy - the lack of any completely dependable criterion as to where to place the reference axes. And when mathematical specifications for simple structure are written in the form of analytical rotation models (e.g., varimax or promax), the model may not fit psychological reality."

Were generally agreed upon external criteria available, a criterium rotation might render factors ( -and labels- ) to span the resulting n-dimensional personality space in a way, more convenient for experimentation and manipulation (Guildford & Hoepfner, 1969; Elshout e.a., 1975).

(For a clear demonstration of these principles on relatively simple data, i.e. measures of books or coffee cups, refer to Overall (1964), Cattell and Dickman (1962) and Cattell and Sullivan (1962).)

However, when we reach for such external criteria, some difficulties arise. Personality dimensions refer to differences in personality. Differences in personality stem from a variety of variance- sources (Cattell, 1950; Hettema, 1967; Smid, 1975). To begin with, differences in personality refer to differences in judgment by other people. Important sources of variance can furthermore be found in the domain of innate properties, the domain of environmental influences on development, the domain of social roles, etc. and at the same time all these sources

of personality-variance may be expected to interact with her. If a personal model is to be of maximum use from an experi¬mental and pragmatic viewpoint, it would be most convenient if it contained orthogonal factors ( -and labels to describe them- ) each of which relates exclusively to just one of these sources of personality. However, this is impossible for the following reasons-;. Suppose for instance that certain innate properties account for an important part of personality-variance (e.g., genetical factors influencing physical strength). Then almost by definition these genetic factors for strength will also influence: a) the probability that an individual adopts certain social roles; b) the probability of profiting by learning from or suffe¬ring irrepairibly from environmental influences; c) the probability of evoking certain judgments from other people; d) etc. When a strong individual has to compete for a dominant position with weak individuals, the chances of success are unequal. The acquired dominant position will determine in its turn part of the individual's behaviour. In the same way, strong individuals will be better able to learn from harsh environmental influences and avoid the suffering of irrepairable damage, thus increasing