978E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995person's quality of life and/or on that of others. The idea of persistence is formally expressedin the American Psychiatric Association (APA) Diagnostic and Statistical Manuals, DSM-IV(APA, 1994) and DSM-III-R (APA, 1987) as the diagnostic criterion that personality disordersexpress their e€ect from late adolescence and do not relapse and remit in the mannercharacteristic of clinical syndromes. Personality disorders are diagnosed on Axis II of the DSMscheme and clinical syndromes on Axis I. The concept of personality disorder has its origins inpsychiatry, but clinical and sub-clinical manifestations of these disorders are also of interest topersonality psychologists. There are however contradictions and tensions in how personalitydisorders are described and characterised in di€erent areas of study. Psychiatric diagnosis hashistorically taken a classi®catory viewpoint: a personality disorder is either present or it is not,and existing clinical scales for the assessment of personality disorders re¯ect this. Traitpsychologists, taking the converging consensus on the existence of a small number of broaddimensions which characterise normal personality as a starting point, prefer to adopt adimensional approach. Whilst a technical reconciliation of these two views can be obtained byregarding a diagnosis as arising by applying a threshold to an underlying continuous variable,such a reconciliation is only well-founded if the relevant dimensional variable has theappropriate psychometric properties. These considerations have provided the impetus for anumber of studies which have examined both the psychometric validity of personality disorderscales and the extent to which clinical personality disorders can be regarded as representingextremes of traits found in the general population.1.1. Problems with current personality disorder taxonomyThe DSM-III-R (APA, 1987) scheme de®nes 12 personality disorders, which are categorisedinto three broad clusters. Cluster A, `odd or eccentric', comprises Paranoid, Schizoid andSchizotypal personality disorders. Cluster B, `dramatic, emotional or erratic', containsAntisocial, Borderline, Histrionic and Narcissistic personality disorders. Avoidant, Dependent,Obsessive-Compulsive and Passive-Aggressive are assigned to cluster C, `anxious and fearful'.Both these levels of description have been questioned by trait psychologists. The frequentoccurrence of a diagnosis of two or more personality disorders in the same patient suggeststhat the current categories lack discriminant validity (Clark, Livesley & Morey, 1997). Theexistence of associations among personality disorder scales is con®rmed by the large number ofsigni®cant correlations between scores on these scales, whilst the conceptual overlap ofdiagnostic criteria for di€erent personality disorders leads to the same conclusion. Theseproblematic aspects of the diagnosis of personality disorder have been extensively discussed inthe literature (see for example Blais & Norman, 1997; Clark et al., 1997; Deary, Peter, Austin& Gibson, 1998; Livesley, 1998; Schroeder, Wormworth & Livesley, 1992; Sher & Trull, 1996;Widiger, 1992). It is unclear if such associations should be ascribed to genuine diagnosticconfusion or to an underlying common cause for disorders which frequently co-occur. It ispossible that a more parsimonious description of personality disorders might be obtained bymerging certain diagnostic categories but there is at present no theoretical basis for doing so.From a psychometric viewpoint, current personality disorder scales are unsatisfactory sinceboth test-retest reliabilities and (for interview-based assessments) inter-rater reliabilities arefound to be modest at best (Zimmerman, 1994). There are also problems of convergent
E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 979validity, i.e. the extent to which two or more di€erent instruments for the assessment ofpersonality disorders give consistent diagnoses (Clark et al., 1997). At the scale level, theexistence of the three clusters can be questioned, as the clusters lack conceptual consistency.Thus for example Paranoid, Antisocial and Passive-Aggressive do not appear to ®t well withother members of their respective clusters, or indeed with their general cluster description.In order to circumvent the psychometric problems of existing clinical scales for themeasurement of personality disorders, some researchers have adopted the approach of factoranalysing an item pool derived from ®rst principles to span the range of personality disordersymptomatology (Clark, 1993; Harkness, 1992; Livesley, 1986, 1987; Livesley & Jackson, 1992;Livesley, Jackson & Schroeder, 1989; Schroeder et al., 1992). This method does not replicatethe personality disorder categories of the DSM classi®cation, although a degree of overlapbetween the constructs derived from the two approaches can be recognised.1.2. Associations between normal personality and personality disordersThere is an emerging consensus that normal personality can be described by ®ve broadfactors: Neuroticism, Extraversion, Openness/Culture/Intellect, Agreeableness andConscientiousness (Matthews & Deary, 1998). Versions of this ®ve-factor model of personalityhave proved to be highly replicable between studies and across cultures (Deary & Matthews,1993). In this context it is clearly of interest to establish whether the same ®ve factors arepresent in the description of abnormal personality, or whether, alternatively, personalitydisorders exist in a distinct universe of their own, separate from normal traits. To this end anumber of studies have been undertaken which aim to address this question and to apply theinsights obtained in the construction of improved diagnostic instruments for personalitydisorders. Whilst these studies are not directly comparable in that they have involved the useof a number of di€erent personality disorder inventories, it is nonetheless possible to extractsome general guiding principles.Factor analytic studies have demonstrated the existence of broad superordinate dimensionswhich can be extracted from personality disorder inventories; the use of joint factor analysiswith normal personality measures has proved to be a powerful technique in establishing therelations between normal and abnormal personality (Costa & Widiger, 1994). A large numberof studies have also reported correlations between personality disorder and normal scales.Results from both factor-analytic and correlational studies are reviewed below. The growingbody of evidence from these studies for a dimensional view of abnormal personality stronglysuggests that the current diagnostic criteria for personality disorders should be supplementedor replaced by a dimensional approach (see for example Blackburn, 1988; Clark et al., 1997;Cloninger, Svrakic & Przybeck, 1993; Costa & Widiger, 1994; Livesley, 1995; Schroeder et al.,1992; Tyrer, 1988; Widiger, 1992; Widiger & Shea, 1991).Another question which needs to be addressed is that of the precise details of theconnections between personality disorders and extreme scores on normal personalitydimensions: i.e. is the existence of extreme scores on certain combinations of normalpersonality dimensions a necessary and sucient condition for the existence of a personalitydisorder or do other considerations need to be taken into account? It is also necessary tocharacterise areas where normal personality and personality disorders fail to overlap. One
980E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995example of this is the weak or zero associations found between personality disorders and thenormal personality dimension of Openness (Schroeder et al., 1992).1.3. Factor analytic studiesStudies of clinical and normal samples report similar patterns of correlations amongpersonality disorder scales (Livesley, Jackson & Schroeder, 1992; Livesley, Jang & Vernon,1998; Tyrer & Alexander, 1979). However, these replicable patterns do not re¯ect the hierarchyof personality disorder proposed in the DSM system. Many of these studies have employed themethod of joint factor analysis with normal personality scales, enabling the factors to becharacterised by their normal personality scale loadings. In some studies a three-factorstructure has been found, comprising: (a) a personal distress factor associated with Neuroticismand having large loadings from most of the personality disorders; (b) a factor associated withhigh Psychoticism or low Conscientiousness/Agreeableness with Antisocial as its largestpersonality disorder loading; and (c) a social avoidance factor characterised by a large negativeloading from Extraversion and positive loadings from Avoidant and/or Schizoid disorders.This factor structure was found to be consistent between clinical and non-clinical populationsby O'Boyle (1995) and O'Boyle and Holzer (1992). Other studies have obtained four factors,with the ®rst three being similar to those of the aforementioned three-factor solution and afourth having Obsessive-Compulsive disorder as its largest loading. Mulder and Joyce (1997)proposed the `four As' labelling for these factors: antisocial, asocial, asthenic (personaldistress), and anankastic (obsessive-compulsive). A similar four-factor structure has been foundusing a variety of di€erent instruments and assessment methods (Deary et al., 1998; Livesley etal., 1998; Schroeder & Livesley, 1991; Tyrer & Alexander, 1979; Presly & Walton, 1973). Inparticular the recent large-scale study reported by Livesley et al. (1998) demonstrated a fourfactorstructure with factors labelled Emotional Disregulation, Dissocial Behaviour, Inhibitionand Compulsivity, which replicated between general population and clinical groups.Some studies have produced a higher-order structure with ®ve factors. Factors whichappeared consistent with four of the Big Five (Neuroticism, Extraversion, Agreeableness andConscientiousness) were found in a higher-order analysis reported by Clark, Livesley,Schroeder and Irish (1996), with the remaining factor representing dependency and need forapproval. A joint analysis of NEO-PI and personality disorder scales by Schroeder et al. (1992)gave similar results, with four of the factors being de®ned by large loadings from Neuroticism,Extraversion, Agreeableness and Conscientiousness respectively; the ®fth factor, associated withdiculty with self-disclosure and expression of emotion, had moderate negative loadings fromExtraversion and Openness. Nestadt et al. (1994) obtained a ®ve-factor solution withdimensions of Scrupulousness, Timidity, Animation, Trust and Warmth.Although alternative numbers of higher-order factors are still under consideration, theindications from these studies is of an encouraging convergence on a near-common higherorder factor structure from di€erent starting points in terms of both normal and clinicalpopulations, and di€erent diagnostic instruments. The latter include DSM-III-R (SCID-II), theDimensional Assessment of Personality Pathology Ð Basic Questionnaire (DAPP-BQ, Livesley& Jackson, in press), the Personality Disorder Questionnaire-Revised (PDQ-R, Hyler et al.,
E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 9811988) and the Schedule for Nonadaptive and Adaptive Personality (SNAP, Clark, 1993). Ittherefore seems likely that such a structure may capture major aspects of personality disorder.1.4. Correlations between abnormal and normal personality scalesTable 1 summarises the strongest and most consistent associations found in correlationalstudies of the relationships between the personality dimensions of the ®ve-factor model ofnormal personality and personality disorder scales. These studies (Coolidge et al., 1994; Costa& McCrae, 1990; Duijsens & Diekstra, 1996; Hyer et al., 1994; Soldz, Budman, Demby &Merry, 1993; Trull, 1992; Wiggins & Pincus, 1989; Yeung, Lyons, Waternaux, Faraone &Ming, 1993) include results from both clinical and non-clinical samples. The strongestassociations are highly consistent across studies. Table 1 shows that the most common form ofassociation between a major normal personality dimension and personality disorder involvesNeuroticism, which is found to be consistently positively correlated with Avoidant, Dependent,Passive-Aggressive Self-Defeating, Paranoid, Schizotypal and Borderline personality disorders,with weaker evidence for associations with Obsessive-Compulsive, Schizoid and Antisocial.Low scores on Agreeableness can also be seen to play a major role in personality disorder,with negative correlations between Agreeableness and Obsessive-Compulsive, Passive-Aggressive, Schizotypal, Borderline and Antisocial personality disorders and possibly also withSelf-Defeating and Narcissistic. Extraversion is associated positively with Histrionic disorderand negatively with Avoidant, Schizotypal, Schizoid and possibly Dependent and Obsessive-Compulsive disorders. Low Conscientiousness is a feature of Passive-Aggressive and Antisocialdisorders, with possible e€ects for Dependent, Histrionic and Borderline. Openness hasTable 1Summary of associations found between DSM-III and normal personality dimensionsN E O A CAvoidant ++ a Dependent ++ Obsessive-Compulsive + Passive-Aggressive ++ Self-defeating ++ Paranoid ++ Schizotypal ++ Schizoid + Histrionic ++ NarcissisticBorderline ++ Antisocial + a Note: ++, denote associations which are strongly consistent between studies; +, denote less consistent associationswhich are nonetheless found in 50% or more of studies. Abbreviations: N, Neuroticism; E, Extraversion;O, Openness; A, Agreeableness; C, Conscientiousness. Studies used in the construction of this table were Coolidgeet al (1994); Costa and McCrae (1990); Duijsens and Diekstra (1996); Hyer et al. (1994); Soldz et al. (1993); Trull(1992); Wiggins and Pincus (1989); Yeung et al. (1993).
982E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995possible negative associations with Dependent and Schizoid. It should be noted that a widerange of instruments for both the normal and personality disorder scales were used in thesestudies, so the weaker e€ects noted in Table 1 (or the lack of e€ects which might be expectedon theoretical grounds) cannot be regarded as de®nitive.The smaller number of studies reporting associations between Eysenck scales and personalitydisorder scales give a broadly similar picture (Deary et al., 1998; O'Boyle, 1995), withPsychoticism replacing low Agreeableness and Conscientiousness.Most of the associations shown in Table 1 are readily interpretable in terms of the de®ningfeatures of the various personality disorders. In terms of the ®ve-factor model of personality,the overall implication of Table 1 is that not all of the ®ve factors are equally salient in thecharacterisation of personality disorder; in particular the overlap between the personalitydimension of Openness and personality disorders is very weak. It has been suggested that bothhigh and low Openness scores might be associated with personality disorder, with high scoresbeing associated with disordered thought processes and low scores with maladaptivein¯exibility (Costa & McCrae, 1992). These associations do not however emerge clearly fromTable 1, apart from possible negative associations with Dependent and Schizoid personalitydisorders. It has also been conjectured (Widiger et al., 1994a) that high scores on Opennesswould be associated with Schizotypal personality disorder but this is not con®rmed; it ispossible that the Openness dimension as currently de®ned does not capture those elements ofdisturbed thought patterns relevant to this disorder. Taken together, the results of correlationaland factor analytic studies suggest that an appropriate higher-order model of personalitydisorder may in fact be a `Big Four' one.1.5. The present studyIn this report we present an item-level factor analysis of the Structured Clinical Interview forDSM-III-R (SCID-II) completed by a group of normal participants. Using this method we candiscover whether the 12 separate personality disorders emerge from the items. Although thevalidity of the current conceptualisation of personality disorder has been criticised, as discussedabove, item-level analysis of personality disorder scales is nonetheless valid. This is becauseeach item represents a symptom which has been identi®ed by clinicians as a signi®cantindicator of disordered or maladative personality. It is therefore appropriate to examine theitems and investigate the hierarchical structure that they form and to investigate associationsbetween this structure and well-validated normal personality traits. Accordingly, in this studywe also report associations with factors derived from the item-level analysis of the SCID-II andEysenck's personality scales.2. Method2.1. ParticipantsFour hundred ®rst year undergraduate students at the University of Edinburgh wererecruited. Because the participants were approached individually, as described below,
compliance was high (above 95%). The group comprised approximately equal numbers ofmales and females of average age close to 19 years.2.2. Materials2.2.1. Eysenck Personality Questionnaire Revised (EPQ-R; Eysenck, Eysenck & Barrett, 1985)This scale has 100 true/false response items and assesses the personality traits ofNeuroticism, Extraversion and Psychoticism. It has a Lie scale to detect socially desirableresponding.2.2.2. Structured Clinical Interview for DSM-III-R Personality Disorders Questionnaire (SCID-II; Spitzer, Williams, Gibbon & First, 1990)This has 113 no/yes response items which assess twelve categories of personality disorder:Avoidant, Dependent, Obsessive-Compulsive, Passive-Aggressive, Self-Defeating, Paranoid,Schizotypal, Schizoid, Histrionic, Narcissistic, Borderline and Antisocial. One question wasexcluded in order not to o€end the participants: No. 106 ``Did you ever force someone to havesex with you?'' In the analyses presented below, items 107±113 from the original questionnaireare renumbered 106±112. The items for the Antisocial scale (102±112 in the revised numbering)refer to ``things you may have done before you were ®fteen''.2.3. ProcedureEach potential participant was approached in his/her room at University of Edinburgh Hallsof Residence and asked to take part in the study. The questionnaire response formats wereexplained and participants were left alone for about one hour to complete the questionnaires.Questionnaires were collected by the investigator and checked for completeness. Ethicalpermission for the study was obtained from the Halls of Residence Committee.2.4. AnalysisE.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 983In a previously reported analysis of these data (Deary et al., 1998) associations between thetwelve SCID scale scores and Eysenck scales were described; item-level analysis was con®ned toreporting of the internal reliabilities of the SCID scales. In the present study an item-levelanalysis was performed in order, in the ®rst instance, to test if some or all of the twelve scalesemerged from a factor analysis of the items. A series of scale-level analyses based on theoutcome of the item-level analyses were then performed.2.4.1. Calculation of the tetrachoric correlation matrixA potential diculty with a factor analysis of the SCID scales is that they are scored asbinary variables. Use of conventional Pearson correlations between such variablesunderestimates the degree of association between items because the maximum value of thePearson correlation between two binary items is constrained to be less than unity except whenthe two items have the same proportions of `yes' and `no' responses (Carrol, 1961). Suchrestrictions on maximum correlations can lead to biased and incorrect outcomes in factor
984E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995analysis (Olsson, 1979), including the appearance of spurious `diculty' factors (Tellegen,1993). In this work we instead used tetrachoric correlations, which give a better estimate of thedegree of association between binary variables. The theory underlying the tetrachoriccorrelation coecient is that the observed 2 2 table derived from the responses to a pair ofbinary items arises from an underlying bivariate normal distribution in which two continuousvariables have been converted to binary variables by the application of a thresholding process.Given the 2 2 table, a maximum likelihood estimation of the tetrachoric correlation providesestimates of both the thresholds and the Pearson correlation (Olsson, 1979). In the presentwork we use an approximate formula for the tetrachoric correlation coecient which is simpleto implement in a computer program and compares well with the full maximum likelihoodcalculation (Camp, 1934; Rae, 1997). Matrices of tetrachoric correlations can be calculated inthe EQS structural equation modelling package (Bentler, 1995), but the maximum matrix sizeis currently restricted to 20. A test of a subset of 100 calculated correlations against the exactvalues obtained from EQS showed good agreement between the exact and approximate values.In the calculation of the tetrachoric correlation matrix item 112 (``Did you ever rob or mugsomeone?'') was omitted from the analysis on account of its very poor psychometric properties(only three `yes' responses from our 400 participants). The results presented below used thecorrelation matrix derived from the remaining 111 items. The error analysis referred to aboveshowed that the absolute percentage error distribution was strongly right-skewed with a meanof 0.24%; 98 of the errors were below 1.3%. The two outlying values were 1.8%, 2.7%. Theseresults suggest that the method used to approximate the tetrachoric correlations was of highaccuracy. As would be expected, the tetrachoric correlations were found to be uniformly largerin magnitude than Pearson correlations calculated directly from the binary responses.2.4.2. Factor analysis of the tetrachoric correlation matrixFig. 1 shows the ®rst 50 eigenvalues of the matrix of tetrachoric correlations. It can be seenfrom this diagram that there is a strong ®rst factor and clear breaks at three and eight factors.The general factor and the three- and eight-factor solutions were selected for further study. Itshould be noted that an analysis based on Pearson correlations, not reported here but availablefrom the authors on request, gave very similar factor structures. A full tabulation of the itemlevelresults described below is not presented here but is also available from the authors onrequest.126.96.36.199. Three-factor solution. The three-factor solution was obtained using the EQS EPIC routinefollowed by orthosim rotation. This factor extraction method is based on a method inwhich the unique variances are initially taken as equal; the orthosim rotation method producesresults close to those of varimax rotation (Bentler & Wu, 1995). The three factors explained28% of the items' variance.188.8.131.52. Eight-factor solution. The eight-factor solution was obtained using a direct oblimin rotation,as it was anticipated that a high-dimensional representation of the SCID items waslikely to display correlations between scales, as is found in higher-order analyses of the SCIDscales themselves. The eight factors explained 44% of the variance.
E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 985Fig. 1. Scree diagram of the ®rst 50 eigenvalues of the item-item correlation matrix.2.4.3. Associations between derived factors and Eysenck personality scalesIndividuals were assigned scores on each of the factors of the three- and eight-factorsolutions by summing up their scores on items with high loadings on each factor in turn (usingweights of +1 or 1 corresponding to the sign of the loading). For the three-factor solution alarge loading was de®ned to be of modulus above 0.4; the corresponding cut-o€ for the eightfactorsolution was taken to be 0.3. The problem of cross-loading items was resolved byassigning each cross-loading item to the factor on which its loading had the largest modulus.Associations between the three- and eight-factor item-level solutions and the Eysenckpersonality scales are shown in Table 2(a) and Table 2(b) respectively. Regressions of eachfactor score derived from the eight-factor solution on the Eysenck scale scores were alsocalculated and are shown in Table 2(b).2.4.4. Higher order analysis of the eight-factor solution.Intercorrelations among the eight oblique factors are shown in Table 3. Internal reliabilitiesare shown on the diagonal. All the correlations are signi®cant, indicating that there is muchTable 2(a)Correlations between three-factor solution scores and Eysenck scalesP a E N LFactor 1 0.11 0.06 0.71 0.25 Factor 2 0.49 0.05 0.13 0.48 Factor 3 0.07 0.51 0.50 0.03a Note: N, Neuroticism; E, Extraversion; P, Psychoticism; L, Lie scale. p < 0.05, p < 0.01, p < 0.001.
986E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995Table 2(b)Associations between eight-factor solution scores and Eysenck personality scalesCorrelationsMultiple RegressionP a E N L Var 1 Var 2 Var 3 Var 4Narcissistic 0.27 0.18 0.44 0.33 N(0.19) L(0.26) E(0.31) P(0.34)Antisocial 0.44 0.01 0.13 0.40 P(0.19) L(0.26) N(0.27)Suspicious Avoidance 0.25 0.29 0.23 0.17 E(0.08) P(0.16) N(0.19)Need for Others 0.06 0.14 0.48 0.11 N(0.23) E(0.28)Obsessive-Compulsive 0.18 0.09 0.16 0.14 P(0.03) L(0.08) N(0.09) E(0.10)Ego Strength 0.06 0.31 0.68 0.17 N(0.47) E(0.50) L(0.51) P(0.51)Eccentric 0.26 0.20 0.32 0.18 N(0.10) P(0.17) E(0.22)Hostile Obstructive 0.28 0.04 0.30 0.32 L(0.10) N(0.17) P(0.20)a Note: N, Neuroticism; E, Extraversion; P, Psychoticism; L, Lie scale. p < 0.05, p < 0.01, p < 0.001. Cumulativeadjusted R 2 values for stepwise multiple regressions are given in parentheses.redundancy among the eight oblique factors. A joint principal components analysis followedby varimax rotation was performed on these eight factors and the EPQ scales. Although,technically, the rotated principal components should not be described as factors, this usage iswidespread and convenient. Examination of the scree diagram suggested a four-factor solution,explaining 64.5% of the variance. These factors are shown in Table 4.3. Results3.1. Interpretation of the factor solutions from the item-level analysis3.1.1. The general factorAlmost all the 111 items had positive loadings on the general factor with 77 (69%) of theitems having loadings of 0.3 or above. Three examples of the highest-loading items are `Doyou often feel bored or empty inside?' (Borderline), `When you see people talking, do youoften wonder if they are talking about you?' (Schizotypal), `When you are criticised do youoften feel very angry, ashamed or put down even hours or days later?' (Narcissistic). Thisfactor clearly corresponds to a measure of generalised psychological distress and/or emotionalsensitivity. A tendency for a strong general `distress' factor to emerge from psychopathologyscales has been noted in other studies (Krug and Laughlin, 1977; O'Boyle, 1995; Schwartz,1976).3.1.2. Three factor solutionFactor 1 contains items from a wide range of SCID scales with borderline, schizotypal,paranoid and narcissistic items dominating; this factor has some resemblance to the general`distress' factor described above. High scores on this factor correspond to emotional lability,need for admiration and fears associated with loss of close relationships and of beingmistreated by others.
Table 3Intercorrelations of eight-factor personality scalesNarcissistic Antisocial SuspiciousAvoidanceNeedfor OthersObsessive-CompulsiveEgoStrengthEccentricNarcissistic 0.73Antisocial 0.28 a 0.74Suspicious Avoidance 0.22 0.34 0.58Need for Others 0.37 0.18 0.15 0.73Obsessive-Compulsive 0.18 0.15 0.16 0.21 0.56Ego Strength 0.36 0.20 0.32 0.39 0.16 0.81Eccentric 0.27 0.15 0.10 0.32 0.19 0.27 0.57Hostile Obstructive 0.36 0.24 0.19 0.27 0.10 0.40 0.26 0.61a Note: p < 0.05, p < 0.01, p < 0.001. Internal reliabilities appear on the diagonal.HostileObstructiveE.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 987
988E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995Table 4Joint factor analysis of the eight SCID-derived scales and EPQ factorsFactor I Factor II Factor III Factor IV CommunalityP a 0.06 0.78 0.12 0.39 0.77E 0.05 0.11 0.88 0.13 0.80N 0.82 0.04 0.30 0.06 0.76L 0.17 0.68 0.07 0.12 0.50Narcissistic 0.61 0.37 0.12 0.08 0.53Antisocial 0.08 0.76 0.14 0.18 0.64Suspicious Avoidance 0.12 0.47 0.58 0.21 0.62Need for Others 0.72 0.03 0.11 0.18 0.56Obsessive-Compulsive 0.16 0.08 0.03 0.92 0.87Ego Strength 0.73 0.02 0.49 0.08 0.78Eccentric 0.57 0.21 0.28 0.04 0.45Hostile Obstructive 0.52 0.39 0.10 0.14 0.46a Note: P, Psychoticism; E, Extraversion; N, Neuroticism; L, Lie scale; loadings above 0.4 shown in bold. Factorsobtained by principal components method with varimax rotation.Factor 2 is dominated by the Antisocial scale, with all items from this scale having largeloadings, but also includes items derived from other scales associated with emotional coldness,manipulative behaviour and self-centredness (e.g. Narcissistic item 78: `Have you sometimeshad to use other people to get what you wanted?'). This factor appears to capture thecharacteristic features of psychopathy (Hart & Hare, 1994). The psychopathy construct has abroader psychological focus than that of Antisocial personality disorder, includingmanipulative behaviour, grandiosity and lack of empathy as well as performance of criminal orantisocial acts. It is of interest in this context that a large number of the high loading noncriminal/conductitems on Factor 2 are derived from the SCID Narcissistic scale.Factor 3 is dominated by items from the avoidant scale; these are combined with items fromother scales related to avoidance and fear of social interactions. This factor hence highlightsvarious aspects of social distress. More caution is required in accepting this factor, perhaps,than the previous two. Its very highest loading items are quite homogeneous, and carry anarrow content related to avoiding social situations and interactions with others. For thisreason, the question of the relative breadth of this potential factor must be raised.3.1.3. Eight factor solutionFactor 1, termed Narcissistic, comprises a combination of items drawn mainly from theHistrionic, Borderline and Narcissistic scales. These items related to emotional lability and theimportance of being noticed and admired by others. The two highest loading items areHistrionic item 72 (`Do you often dress in a sexy way even when you are going to work ordoing errands?') and Borderline item 92 (`Do you often have temper outbursts or get so angrythat you lose control?'). Factor 2, termed Antisocial, is dominated by items from the Antisocialscale; items from other scales relating to emotional coldness and a self-harm item from theBorderline scale also load on this factor. Factor 3, designated Suspicious Avoidance, containsitems drawn from a wide range of SCID scales which relate either to social avoidance or to a
E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 989lack of empathy or trust in relation to others. The two highest loading items are Schizoid item55 (`Would you rather do things alone than with other people?') and Self-Defeating item 41(`When people try to help you, do you make it hard for them?'). Factor 4, designated Need forOthers, contains items from a range of scales relating to fear of losing close relationships andof being mistreated by others. Factor 5, termed Obsessive-Compulsive, is dominated by itemsfrom the SCID Obsessive-Compulsive scale; these items refer to high standards, rule-keepingand attention to detail. Factor 6, designated Ego Strength contains items associated withavoidance of social situations, vulnerability to criticism and indecision. Factor 7, termedEccentric, is dominated by items from the Schizotypal scale relating to magical thinking; itemsrelated to unconventionality and a preference for being alone drawn from other scales alsoappear. This scale is clearly dominated by the odd/eccentric aspect of schizotypal behaviourwith the social avoidance aspect making a much smaller contribution. Factor 8, designatedHostile Obstructive, is dominated by the Passive-Aggressive scale and contains mainly workrelateditems associated with `accidental'/deliberate bad performance combined with feelings ofbeing obstructed by and underlying superiority to others.Comparing the eight-factor solution with the original SCID-II scales the ®nding is that theAntisocial, Obsessive-Compulsive, Schizotypal (especially the `magical thinking' aspects) andPassive-Aggressive constructs emerge relatively clearly as factors. The Narcissistic scale derivedfrom the item-level analysis has a somewhat di€erent ¯avour from DSM-III-R narcissism, withthe inclusion of items relating to emotionality absent from the original DSM de®nition of thisdisorder. The remaining four factors all de®ne problems in relationships with others, butdelineate the domains of such problems in ways which blend features of a number of DSM-III-R scales.Considering general properties of the eight factor solution, one feature of interest is that atthis level of description the scales which can be derived from a direct analysis of the item pooldo not correspond either in number or content to the structure expected by referring to theSCID subscales. This raises the question of the extent to which such scales might be used as analternative diagnostic scheme. Reference to Table 3 shows that these scales are universally,signi®cantly intercorrelated and so cannot be de®ning a set of diagnostically independentpersonality disorders. Four of the scales have satisfactory internal reliabilities but theremainder are of low reliability. For these reasons we regard these results as suggestive andinteresting rather than proposing that they be adopted for diagnostic purposes. It is however ofinterest that the proportion of scales with satisfactory internal reliability (4/8) is substantiallyhigher than that reported for the original SCID scales (2/12) in these data (Deary et al., 1998).The high degree of intercorrelation between the scales provides the rationale for the higherorder factor analysis discussed in Section 184.108.40.206. Associations with Eysenck scalesTable 2(a) shows that for the three-factor solution Factor 1 is strongly aligned withEysenck's N dimension, with much smaller contributions (positive and negative respectively)from P and L. Factor 2 is associated with P and L () with a small contribution from N.Factor 3 is associated with N and E (). Thus the three-factor solution shows two of theEysenck factors, N and P emerging clearly from the SCID item pool. The third factor,
990E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995correlating equally and oppositely with N and E is closer to the Anxiety factor of Gray (1991);it contrasts neurotic introversion with stable extraversion.For the eight factor solution, a listing of the signi®cant correlations shown in Table 2(b) indescending order for each factor gives: Narcissistic (N, () L, P, E); Antisocial (P, () L, N);Suspicious Avoidance (() E, N, P, () L); Need for Others (N, E, () L); Obsessive-Compulsive (() P,N,() L); Ego Strength (() N, E, L), Eccentric (N, P, E, () L); HostileObstructive (() L, N, P). Regression of each factor score on the Eysenck scale scores, alsoshown in Table 2(b) gives similar results. The large signi®cant correlations of all scales with Ncon®rms the results of previous studies, summarised in Table 1, which show that Neuroticism/Negative A€ectivity is a key variable underlying personality disorders. Signi®cant correlationswith both P and L are found for most of these scales; only the Need for Others and EgoStrength scales fail to correlate signi®cantly with P. Correlations with P are positive, except forObsessive-Compulsive; the negative association here presumably relates to maladaptive overconscientiousnesswhich would be expected to be associated with low P scores. From Table2(b) it can be seen that the Eysenck scales perform poorly in accounting for the variance of theObsessive-Compulsive factor; a possible explanation for this is that the Eysenck scales lack aConscientiousness measure. The nature of Eysenck's L scale deserves some attention. In thepresent sample the correlation between P and L is 0.35. The existence of a correlation of thismagnitude suggests some construct overlap; it can be argued that this arises because high Pscorers are prepared to report socially undesirable responses to the L scale. However, themultiple regression results indicate that L scale explains variance in several of the eight factorsnot accounted for by P. Extraversion plays a lesser role than P and N in these factors, but isassociated signi®cantly with Narcissistic, Suspicious Avoidance, Need for Others, Ego Strengthand Eccentric.3.3. Joint analysis of the eight-factor solution and Eysenck scalesThe scree diagram clearly indicated a four-factor solution. The four factors, shown in Table4, are very similar to those found in other higher-order factor analyses of personality disorderscales discussed in the introduction. The ®rst three factors each have their highest loading onone of the Eysenck scales. Factor I, which has Neuroticism as its largest loading, also has largeloadings for Narcissistic, Need for Others, Ego Strength (), Eccentric and HostileObstructive. Factor II, with Psychoticism as its largest loading, has Antisocial as its largestpersonality disorder loading. Large loadings are also found for Suspicious Avoidance and theEysenck Lie scale (); there is also a moderate loading for Narcissistic. Factor III hasExtraversion as its largest loading and has Suspicious Avoidance () as the largest personalitydisorder loading; there is also a large loading for Ego Strength. Factor 4 is characterised by alarge loading for Obsessive-Compulsive; there is also a negative loading for Psychoticism.These results are in reasonable agreement with previous work described in the introduction andin particular con®rm the `four As' model (Mulder & Joyce, 1997). It is also possible toestablish a tentative connection with the extensive literature on the associations betweenpersonality disorders and the ®ve-factor model of personality. It has frequently been arguedthat in the ®ve factor model framework Psychoticism can be regarded as a blend of lowAgreeableness and low Conscientiousness (Eysenck, 1992). In these terms, the present results
E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995 991can be regarded as separating out the low Agreeableness aspect of Psychoticism (which appearson Factor II with the `disagreeable' scales Antisocial and Suspicious Avoidance) from the lowConscientiousness aspect (which loads negatively on factor IV in combination with Obsessive-Compulsive).4. DiscussionIn this paper an item-level factor analysis of the SCID-II personality disorder scales waspresented. This is an important empirical task. The SCID-II items represent decades ofaccumulated clinical wisdom about personality disorder symptoms, and it is necessary todiscover the statistical associations among them rather than accepting the DSM-basedsyndromes and clusters which, by now, are known to have little validity. Three and eight-factorsolutions were examined; the eight-factor solution did not replicate all the personality disordersbut does provide partial psychometric support for the DSM concepts of Antisocial, Obsessive-Compulsive, Schizotypal and Passive-Aggressive disorders. A Narcissism scale also emerges,but with a somewhat di€erent tone to that de®ned by the original DSM-III-R scale.A higher-order factor analysis produces four factors which are consistent with the antisocial,asocial, asthenic and anankastic factors found in previous work (Deary et al., 1998; Livesley etal., 1998; Presly & Walton, 1973; Schroeder & Livesley, 1991; Tyrer & Alexander, 1979).Examination of associations with Eysenck's scales shows that these are readily interpreted andprovide evidence of the overlap between personality disorder and the dimensions of normalpersonality. The existence of associations with a small number of normal personalitydimensions would appear to explain the high degree of construct and diagnostic overlapbetween di€erent personality disorders (Trull, 1992). Although Neuroticism plays a key role inthe majority of personality disorders, Extraversion and Psychoticism also contributesigni®cantly. The `disagreeable' aspect of Psychoticism is associated with several aspects ofpersonality disorder, whilst a negative association between psychoticism and the `anankastic'factor from the higher-order analysis suggests that excessive Conscientiousness can bemaladaptive.Thus, we see the usefulness and the limitations of Eysenck's very broad dimensions intheir application to personality disorder. The N, E and (antisocial aspects of) P dimensionsaccount for much personality disorder variance, but there appears to be a role for aConscientiousness dimension as represented in the ®ve factor model (Costa & Widiger, 1994;Costa & McCrae, 1992, Goldberg, 1993). The absence of a higher-order abnormal factorcorresponding to Openness in the ®ve-factor model may suggest: (a) that there is a real gapin the ®ve-factor model (in the sense that it does not provide a description of the moreextreme forms of disordered thought); (b) a real example of non-overlap of normal andpsychopathological dimensions; or (c) that openness-related disordered personality traits existbut do not present problems that come to clinicians' notice. The ®rst interpretation is inaccord with the general methodological problem in trying to examine normal personality andpersonality disorders on a common metric: measures designed for the normal range ofpersonality may on occasion fail to represent maladaptive behaviour adequately (Widiger &Costa, 1994; Widiger, 1998).
992E.J. Austin, I.J. Deary / Personality and Individual Di€erences 28 (2000) 977±995In addition to these uncertainties about exactly how normal personality andpsychopathology connect, another gap in the current knowledge of psychopathology is thelack of detailed understanding of the biological basis of personality disorders. Siever andDavis (1991) proposed a psychobiological model of psychopathology comprisingdimensions of cognitive/perceptual organisation, impulsivity/aggression, a€ective instability,and anxiety/inhibition spanning both Axis I and Axis II disorders. Associations betweenpersonality disorder scales and the psychobiologically based model of Cloninger have alsobeen investigated. A study of associations between the Temperament and CharacterInventory (Cloninger et al., 1993) and DSM-III diagnoses suggested that clusters A, Band C are associated with low reward dependence, high novelty seeking and high harmavoidance respectively (Svrakic, Whitehead, Przybeck & Cloninger, 1993). It is clearlyappropriate that insights derived from biology and behaviour genetics should be includedin future studies and incorporated into existing diagnostic schemes. In this area thestrongest result is the evidence for common biological/genetic factors underlyingschizophrenia and schizotypal personality disorder. Here the evidence for geneticdi€erences between the a€ected and una€ected has led to the development of argumentsand analyses which run against the trend of most current research in personality disorderby proposing a taxonometric approach to these conditions (Lenzenweger & Kor®ne, 1992).Evidence is emerging of the heritability of other personality disorders (Livesley et al.,1998; Nigg & Goldsmith, 1994; Torgersen, 1980), but the biological processes underlyingthese disorders remain unclear.Whilst awaiting new insights from biology, what is the best way forward in purelypsychometric studies of personality disorders? It seems clear that further re-working of existingdiagnostic scales, which are widely acknowledged to be psychometrically de®cient, can giveonly limited information. Whilst such work has provided valuable insights, alternativeapproaches are clearly required, in order to work towards de®ning new measures of personalitydisorder which will avoid the obvious criticisms of existing measures: `... the current approachto personality disorder is so inconsistent with the evidence that a major reconceptualisation isrequired. A rapprochement between personality disorder and the study of normal personalityo€ers opportunities to develop a new understanding' (Widiger, Schroeder, Jackson & Jang,1994b). Such a new understanding seems overwhelmingly more likely to be obtained if athorough exploration of the item universe describing the personality disorders (Livesley &Jackson, 1992; Livesley et al., 1989; Schroeder et al., 1992) replaces further exploration of theimpasse of existing scales. The use of existing normal personality dimensions as an aid in theestablishment of the key dimensions in this di€erent but overlapping universe promises to givemany valuable insights, but only detailed work at the item level can establish what are the truepersonality descriptors of psychopathology and to what extent normal personality andpsychopathology do indeed blend into one another.In summary, we suggest a re-orientation of some research on personality disorderinstruments. Much current research works at the scale level. This is unhelpful, because there islittle evidence to uphold the validity of many scales. Too little research is conducted at the itemlevel. This is unfortunate, because the items represent the phenomena whose taxonomy has todate been imposed by ®at but must, in research, be discovered.
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