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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 experimental 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 suffering irrepairably 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 their chances of becoming more skillful. This in turn determines part of the individual's behaviour. In this way correlations between genetical factors and other types of personality-sources will prevail and the same probably is true mutatis mutandis for other combinations of personality sources.

This implies that it will be impossible to find pure genetical personality factors, pure developmental personality factors, pure social role factors, etc., that vary independently from one another. In other words, having found an n-dimensional trait-space that describes the correlations between personality descriptive adjectives, and having found an efficient description of the n-dimensional space by an orthogonal simple structure treatment of its principal components, we can almost be certain that each of these resulting orthogonal factors contains elements of many classes of personality-sources, therewith rendering the model sub-optimal from an experimental and manipulative point of view.

Perhaps a more attractive approach is one in which external rotation criteria are obtained from experimental data (Armstrong, 1967; Gorsuch, 1974; Guilford & Hoepfner, 1969). If such criteria are available, orthogonal factors from a simple structure procedure may be replaced by (correlated) canonical factors each of which relates to some major (set of) personality sources and which can be experimentally manipulated and verified.

In this paper we will summarily present a model of personality dimensions and personality dynamics, as may be derived from animal and human behavioural studies ('Model of the dynamics of personality dimensions in mice and other socially living mammals'). External criteria, as derived from that model, are used to replace 6 (orthogonal) principal dimensions of the dutch personality descriptive adjective space, as explored and described by Brokken (1978), by correlated dimensions. It will be argued that the resulting dimensions fit more satisfactorily into the above mentioned systematic theory of personality differences and can therefore more readily be employed in meaningful experimentation and manipulation.

Dutch Personality Descriptive Adjectives

Brokken (1978) developed and investigated an exhaustive list of (1204) dutch personality descriptive adjectives. Ratings on these adjectives were obtained from 200 self and 200 partner raters each of whom used the complete list of 1204 adjectives to rate him/her self or a partner.

The ratings on these adjectives were factor analysed and varimax-rotated for self- and for partner-raters separately. Subsequently the two sets of factors were subjected to a two- sided orthogonal Procrustes rotation. After this procedure Brokken found a one-to-one correspondence between six pairs of self- and partner-factors with Phi(φ)-coefficients of about .80 or higher. Cattell's (1952)scree test for determining the number of factors to be maintained also suggested six dimensions to be a useful number.

These six dimensions were interpreted as is shown in table 1.

Brokken (1978, pp. 51-52) comments on the position of his factors: "It should be noted that the labels for the factors are only very general ones, capturing the tendency of meaning of each factor at most. Frequently, rather unexpected adjectives appear which suggests that other, aesthetically more appealing positions of the factors may be found. In the present study, in which the prediction of variables is a central issue, aesthetically appealing positions of the factors are relatively unimportant because such positions do not increase the predictability of other variables by the factors. Furthermore, as three of the five Norman factors are presented in the factors in their current position while another factor (Conscientiousness) is represented by the factors Dominance and Orderliness, it was decided to postpone new rotations to future research." (The Norman factors Brokken refers to in this quotation are 'Surgency (or Extraversion)', 'Agreeableness', 'Conscientiousness (or Dependability)', 'Emotional Stability' and 'Culture'. With these five dimensions of trait ratings Norman (1963) summarized the structure he found in the use of traits for describing oneself and others.)

table 1: Some high and low loading adjectives on Brokken's six orthogonal dimensions

Table to be added by Rowan

Factor one: Agreeableness or Factor four: Orderliness or Social Desirability Preciseness vriendelijk friendly secuur accurate gastvrij hospitable nauwkeurig accurate eerlijk honest precies precise trouw faithful degelijk sound versus: versus: kwaaddenkend suspicious onnauwkeurig inaccurate onvriendelijk unfriendly slordig slovenly klagerig complaining ordeloos disorderly stiekum underhand slonzig sluttish Factor two: Sprightliness Factor five: Conformity and Stability zonnig sunny alledaags plain actief active bezadigd staid levenslustig sprightly oerdegelijk ultra-steady monter brisk emotieloos unemotional versus: doodkalm cool teruggestrokken withdrawn kritiekloos uncritical lusteloos listless gehoorzaam obedient passief passive slaafs slavish stil quiet conventioneel conventional Vfirsil R ! Factor three: Dominance opstandig rebellious depressief depressive dominant dominant prikkelbaar irr itable hard hard emotioneel emotional zelfverzekerd self-assured kritisch critical onvermerwbaar TTQYl Gil G * unrelenting creatief creative VCI fc> U. D . volgzaam docile Factor six: Introversion - bedeesd bashful Extraversion voorzichtig careful timide timid gesloten uncommunicative rustig quiet introvert introverted bedaard calm versus: kletserig chatty praatgraag talkative opvliegend short-tempered spontaan spontaneous

Model of the Dynamics of Personality in Mice and other Socially Living Mammals

3.1. Mouse behaviour.

Van der Molen (1972, 1981a) collected ethological data on the social behaviour of male house mice, which were living group-wise together for some months in large (150 x 75 cm) observation cages, supplied with food and water ad libitum. The data were analysed by means of an R-type factor analysis in order to be reduced to a limited set of behavioural trait dimensions. In order to rotate the resulting principal components in a useful and meaningful way, rotation criteria were obtained from additional experiments with social roles. These experiments indicated the importance of:

- Three basic types of social roles: Ó (dominant), (compliant subordinate) and cD (outcast), i.e. at least two orthogonal dimensions, and

- Interindividual differences in: 'Level of relevant social skills'.

Rotation of the principal components was subsequently performed in such a way that the factors were either interpreted as social- role factors or as within-role variation between individuals. The analysis resulted in two social role factors and two factors of within-role differences between individuals. The two social role factors accounted for the differences be¬tween , and -males and were labeled as 'Dominant versus subordinate' and 'Socially accepted versus outcast'.

The two personality factors of within-role variance were labeled as 'Active versus inactive' and Explorative and Self-willed versus Social and Compliant'.

Although a good distinction was thus obtained between role- differences and other individual differences, orthogonality of factors had to be abandoned in favour of operational and func¬tional clarity.

No R-type factor was extracted that could account for the differences in social skill, a dimension which was experimentally shown to be of some importance. Not finding this factor was probably due to the fact that the experimental design in ques¬tion was poorly suited for measuring differences in skills in so far as they are related to social roles.

In mice, such differences in skill are expressed through differential probabilities of obtaining the most desired social roles, whereas our ethological raw data were obtained within one social role for each individual.

A dynamic model of personality structures was designed to account for the derived behavioural trait dimensions and their intercorrelations, for differences in skill, and for the expe¬rimental results of manipulation of social roles (fig. 1). Explaining in detail how this dynamic model was arrived at, is beyond the scope of this paper. A full account of its construc¬tion is given elsewhere (Van der Molen, 1981a, ch. VI). Here we shall just indicate the model's most elementary features.

The model allowed for dependency (obliqueness) between dimensions of social behaviour and traits of temperament, thus allowing for functional (cor)relations between these two cate¬gories of personality dimensions.

In addition, the axis' of reference in the domain of temperament traits were chosen in such a way, that their sig¬nificance for the distribution of social roles was clear a- priori.

The model was in accord with the assumption that the inter- individual variance in three independent and genetically deter¬mined qualities is of particular importance for the development of the observed behavioural differences between individuals. These congenital quality-dimensions were called 'Basic energy level' (1), 'Basic need for social contact and interaction' (2) and 'Basic need for having one's way' (3). These three dimen¬sions of basic qualities were suggested to represent together the same-three-dimensional trait space as the set of three basic qualities called 'Basic activity level' (8), 'Stability' (7) and 'Self-will versus compliance' (6) (figs. 1 & 2).

This latter trait dimension was of particular importance for understanding the relations between social-role dimensions and dimensions of temperament. The 'balance between self-willed and compliant tendencies' (6) was defined as the predisposition to assume an outcast cC)-role, rather then a subordenate -role. This basic trait was considered to be expressed in overt beha¬viour as the personality dimension 'Explorative versus social' (6). According to our model the basic trait 'Basic activity level' (8) is expressed in overt behaviour as the trait dimen¬sion 'Active versus inactive'(8). The basic congenital trait 'Stability'(7) is expressed at the level of overt behaviour as the likelihood of acquiring 'Useful skills'(11) given certain circumstances. But it was also indicated that accidental circumstances (12) do play a crucial role in the acquirement of 'Relevant skills'.