Social desirability, defensiveness and self-report psychiatric inventory scores

Psychological Medicine, 1980,10, 735-742 Printed in Great Britain Social desirability, defensiveness and self-report psychiatric inventory scores KATHARINE R. PARKES 1 From the Department of Experimental Psychology, University of Oxford SYNOPSIS The effects of social desirability and defensiveness on scores on 2 self-report psychiatric inventories, the General Health Questionnaire (GHQ) and the Middlesex Hospital Questionnaire (MHQ) were investigated in a female subject group assessed for research purposes in an occupational setting. It was found that defensiveness did not affect the reporting of somatic symptoms, but it significantly affected the reporting of all psychological distress. The effect of social desirability was more specific, only the GHQ social dysfunction subscale showing a significant correlation, an effect attributable to the influence of the setting in which the data were obtained. INTRODUCTION Self-report psychiatric symptom inventories such as the General Health Questionnaire (GHQ) (Goldberg, 1972) and the Middlesex Hospital Questionnaire (MHQ) (Crown & Crisp, 1966) have been widely used to provide a quantitative assessment of non-psychotic psychiatric disturbance in both normal and clinical population groups (for instance, Ballinger, 1975; Howell & Crown, 1971; Smith et al. 1973; Johnstone & Goldberg, 1976; Mann, 1977; Stringers al. 1977). The GHQ is also intended as a screening test and can be used to identify probable psychiatric cases, as in the community survey reported by Finlay- Jones & Burvill (1977). The obvious advantages of such questionnaires as a means of assessing psychiatric disturbance are ease of administration, suitability for use in a group setting, and the fact that medical expertise is not required. However, the use of self-report questionnaires in place of conventional clinical interviews raises important issues concerning the extent to which an individual is willing to endorse items reflecting psychiatric disturbance on a questionnaire. Extensive validations of both the GHQ (Goldberg, 1972; Goldberg et al. 1976), and the MHQ (Crown & Crisp, 1966; Crisp & Priest, 1 Address for correspondence: Dr K. R. Parkes, Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford 0X1 3UD. 0033-2917/80/2828-5710 $01.00 1980 Cambridge University Press 735 1971; Crisp et al. 1978), have demonstrated acceptable levels of validity in terms of overall correspondence between questionnaire scores and clinical ratings, but relatively little attention has been paid to personality variables, such as social desirability and defensiveness, which may adversely affect the validity of individual scores. Goldberg (1972) presented data indicating that scores on the Crowne-Marlowe social desirability scale (Crowne & Marlowe, 1964) and on the Lie scale of the Eysenck Personality Inventory (Eysenck & Eysenck, 1964) were similar for GHQ 'cases' (scores of 12 and above) and 'normals' (scores of 11 and below), although cases tended to have higher Lie scale scores than normals. Goldberg concluded that social desirability was not an important determinant of GHQ scores. However, he found that' defensiveness' was associated with misclassification on the GHQ (Goldberg, 1972; Goldberg ef al. 1976). In these studies defensiveness was assessed clinically, the term being used to describe interview behaviour characterized by suspicion and hostility. In the present work the relationships of measures of social desirability and defensiveness to scores on the GHQ and the MHQ are examined in more detail. Social desirability (Edwards, 1953) refers to an individual's tendency to respond to questionnaire items in such a way as to endorse culturally acceptable statements, and thus to present himself in a favourable light. Crowne & Marlowe

736 K. R. Parkes (1964) saw a generalized 'need for approval' as underlying this tendency. The Crowne-Marlowe social desirability scale consists of statements which are either 'culturally acceptable but probably untrue' or 'probably true but culturally unacceptable'. Responses of'true' to the former and 'false' to the latter thus imply unrealistic claims to virtue which can result from dissimulation or 'faking-good'. Items on the Lie scale of the Eysenck Personality Questionnaire (EPQ-L) (Eysenck & Eysenck, 1975), which was developed as a measure of dissimulation, are essentially similar in concept. The content of some items is common to both scales, although the format differs slightly, the Lie scale being presented in the form of questions. Although originally intended as measures of response bias, there is some evidence that these scales may also measure personality traits such as naivete, conformity, and sensitivity (Kirton, 1977; Brannigan, 1977). Interpretation of Crowne-Marlowe and Lie scale scores as measures of an individual's tendency to present himself in an unrealistically favourable light does not necessarily imply that the scores will show a negative relationship to self-report psychiatric inventory scores under all circumstances. The nature of the relationship will be influenced by the setting in which the assessment is carried out, the subject's appraisal of the social desirability of endorsing inventory items in that particular setting, and the likely consequences of doing so. Michaelis & Eysenck (1971) found that the negative correlation between Lie scale scores and neuroticism was significantly larger when the subjects thought that they were being assessed for personnel selection purposes than when there was little or no motivation for dissimulation, and the same effect would be expected for psychiatric inventory scores. However, the demands and expectations inherent in some assessment situations, particularly medical ones, may lead subjects high in need for approval to report as many or more symptoms than those low in need for approval. This is consistent with Goldberg's (1972) findings, since his data relate to patients attending their general practitioner's surgery. Goldberg suggests that patients may differ from normals in that they become prepared to make socially undesirable statements about themselves but, since patients do not appear to differ from normals in their perception of social desirability items (Edwards, 1957), it is more likely that in medical settings patients do not perceive reporting psychiatric symptoms as socially undesirable. Of relevance in this context is the behaviourist view of social desirability as expressed by Mischel (1968, p. 187): 'The social desirability ratings of test responses provide an index of the reinforcement value of endorsing them...if endorsing X is likely to lead to more positive consequences for the subject than endorsing Y, then, not surprisingly, he will endorse X.' It is possible that expectations inherent in medical settings may lead patients to anticipate social reinforcement and other positive consequences, such as reassurance or treatment from the doctor, as a result of endorsing symptoms of distress. Depending on the circumstances of the assessment and the expectations of the subjects, therefore, social desirability scores, interpreted as a measure of response bias, may show a negative, neutral or positive relationship to psychiatric inventory scores. The term defensiveness refers to a reluctance to acknowledge or reveal to others inner thoughts and experiences, particularly any form of psychological distress such as anxiety, anger or frustration. An individual high in defensiveness will tend to suppress and deny such problems, while low scorers will tend to emphasize or even exaggerate them. As assessed by the Minnesota Multiphasic Personality Inventory (MMPI) K scale (Dahlstrom & Walsh, 1960) or the Adjective Check List Defensiveness scale (ACL-Df) (Gough & Heilbrun, 1965), defensiveness implies only an unwillingness to acknowledge or focus attention on psychological distress, rather than a complete lack of conscious awareness of these difficulties. The MMPI K scale and the ACL-Df scale were both developed empirically by identifying items which discriminated between those individuals whose self-description was congruent with their mental state as clinically assessed, and those whose self-description reflected an unduly favourable degree of adjustment. Items on defensiveness scales are not intrinsically improbable in the way that keyed responses on social desirability scales are, but they reflect a tendency to deny common weaknesses and endorse positive characteristics. The K scale was

Social desirability, defensiveness and psychiatric inventory scores 737 derived from work with psychiatric patients and it is not a good measure of this variable in normal population groups, particularly females (Heilbrun, 1961). The ACL-Df scale was developed as a measure of defensiveness for normal subjects. The relationship between defensiveness and measures reflecting maladjustment is inherently a negative one, and this is consistent with experimental findings (for instance, Redfering & Jones, 1978; Newberry, 1967). From the discussion above, it is apparent that the effects of social desirability on psychiatric inventory scores will be more susceptible to the influence of the external conditions under which the assessment is carried out than the effects of defensiveness. A defensive individual will tend to deny experiencing psychological distress even in situations in which such disclosure would be not only acceptable but positively encouraged. This process, which can be seen as a means of protecting vulnerable self-esteem, is essentially an internal one which is little influenced by situational factors. In contrast, social desirability effects are mediated by external circumstances, the individual high in need of approval responding to his/her perception of the assessment situation in such a way as to gain social approval and reinforcement, whether this be by denying or endorsing symptoms of distress. The effects of social desirability and defensiveness on the reporting of psychiatric symptoms would also be expected to depend on the form and content of questionnaire items. In particular, different subscales may be differently affected, thus possibly distorting the overall pattern of scores. These effects are taken into account in scoring the MM PI diagnostic profile. However, similar effects have not been investigated in relation to inventories such as the MHQ, and the scaled version of the GHQ (Goldberg & Hillier, 1979), which assess current psychiatric disturbance on several subscales. Somatic symptom subscales are of particular interest in this respect since physical symptoms may be perceived as medical rather than psychological in origin, and thus possibly less susceptible to distortions associated with social desirability and defensiveness. In the present work empirical data obtained from a normal population group, assessed for research purposes in an occupational setting, are examined in relation to the issues raised above. The specific empirical questions addressed can be summarized as follows: (i) To what extent are total scores on the GHQ and the MHQ correlated with social desirability and defensiveness? (ii) Are scores on these measures significantly different for cases and normals as identified by the GHQ? (iii) To what extent do different types of symptoms, as categorized by the GHQ and MHQ subscales, show different levels of correlation with social desirability and with defensiveness? METHOD Subjects The subjects in this study were 2 successive intake groups of female student nurses attending an introductory course in nursing. A total of 101 students participated. The average age of the students was 20-1 years, 95 % of them being in the 18-26 years age range. Almost all were of British or Irish nationality. Procedure Two assessment sessions were held with groups of approximately 25 students in an informal classroom setting, the second session taking place 2 days after the first. The procedure followed was the same for each group. Each subject was assigned a number which was used to identify the questionnaires. A list of names and numbers was held by the investigator, but no names were used on the questionnaires and the confidentiality of all individual data was guaranteed. No hospital staff were present during the assessment sessions. Participation in the research was voluntary, but only 5 students declined to participate. Test materials The following personality tests and psychiatric symptom inventories were used in the work reported here: EPQ-L scale (Eysenck & Eysenck, 1975) The EPQ consists of 90 items, 21 of which form the L scale. Subjects respond to each question in a yes/no format. The EPQ yields, in addition to lie scale scores, measures of neuroticism, extraversion, and psychoticism, but only the L

738 K. R. Parkes scale data are reported here. The EPQ-L scale was used in this study in preference to the Crowne- Marlowe social desirability scale as it was developed and standardized on a UK population, and the items were better suited to the subject group concerned. In a separate study carried out under conditions similar to the present work, the correlation between scores on the 2 scales was found to be positive and highly significant ( r = 0-64, N = 100, P < 0001) (Parkes, unpublished data). ACL-Df scale (Gough & Heilbrun, 1965) The ACL consists of a list of 300 adjectives to which subjects respond by checking those which they consider to be self-descriptive. A number of scales can be derived from this protocol, but for the purposes of the present work only the ACL- Df scale was scored. GHQ (Goldberg, 1972) The 60-item version of this inventory was used, and it was scored by the 1-0 'GHQ scoring' method, i.e. each symptom was scored as present or absent during the previous 6 weeks, without regard to severity. This score was designated the GHQ-Total score and, in addition, scores were calculated for each of the 4 7-item subscales (anxiety and insomnia, somatic, severe depression and social dysfunction) derived by Goldberg & Hillier (1979). The proportion of GHQ cases (i.e. GHQ-Total scores of 12 or above) in the subject group was also determined. MHQ (Crown & Crisp, 1966; as modified by D. E. Broadbent & D. Gath, personal communication, 1978) The modified form of this questionnaire consists of 3 subscales (anxiety, somatic symptoms, and depression) of 7 items each, and 1 subscale (obsessional symptoms) which has 4 items. These 4 subscale scores were summed to form the MHQ-Total. In addition, a further 3 items assess obsessional personality traits. The subjects were instructed to report whether they had experienced these symptoms during the past 6 weeks, and responses were scored on a 2-1-0 basis. The EPQ and the ACL were administered during thefirstassessment session and the GHQ and the MHQ during the second session. Statistical analysis Since the distribution of GHQ scores was strongly positively skewed towards higher values, parametric statistics were inappropriate. Kendall's tau was therefore used for correlations involving GHQ scores, and to facilitate comparison the MHQ scores were treated in the same way. RESULTS Means, standard deviations and intercorrelations of EPQ-L and ACL-Df, and of GHQ-Total and MHQ-Total scores The means and standard deviations of scores on the 2 personality measures, EPQ-L and ACL- Df, were 8-2 ±3-5 and 46-1 ±9-4 respectively. These values are not significantly different from the normative data for female population groups (Eysenck & Eysenck, 1975; Gough & Heilbrun, 1965). The correlation between the EPQ-L scores and the ACL-Df scores was positive, as expected, and just reached significance^ = 0-20, jv= 101, P = 005). The range of the GHQ-Total scores was 0-44, with a median value of 4. This non-normal distribution distorts comparisons based on the mean and deviation, but the values given by Goldberg (1972) for female general practice patients suggest that their scores were rather higher than those of the present subject group. More useful for comparison purposes was the percentage of GHQ cases in the subject group. This was 21-8 %, which is in close agreement with that for the equivalent age groups of female subjects in a community survey reported by Finlay-Jones & Burvill (1977). No normative data are yet available for the modified version of the MHQ used in the present study, but the mean MHQ-Total score was 11-7 ±7-2, and the overall correlation between GHQ- and MHQ-Total scores was positive and significant (tau = 0-47, N = 101, P < 0-01), indicating considerable agreement between these measures in spite of differences in the items on the 2 questionnaires. Correlation of EPQ-L and ACL-Df with GHQ- Total and MHQ-Total scores The GHQ-Total scores were significantly negatively correlated with both EPQ-L (tau = 016,

Social desirability, defensiveness and psychiatric inventory scores 739 N = 101, P < 005) and with ACL-Df (tau = -0-18, N = 101, P < 0-05). The correlation of the MHQ-Total scores with EPQ-L was negative, but failed to reach significance (tau = -0-09, N = 101, NS) whereas the correlation of MHQ-Total with ACL-Df was negative and significant (tau = -0-19, N = 101, P < 0-01). Comparison of EPQ-L and ACL-Df scores for GHQ cases and normals In order to allow more direct comparison of the present data with those reported by Goldberg (1972), the subject group was divided into GHQ cases (./V = 22) and normals (N = 79). Mean EPQ-L and ACL-Df scores were calculated for each of these 2 groups. Consistent with the negative correlations reported above, GHQ cases had lower mean ACL-Df scores and lower mean EPQ-L scores than normals, but only for the ACL-Df scores (43-5 + 7-2 for GHQ cases, 46-8 ± 9-9 for normals) did the difference reach significance (/ = 1-75, df = 99, P < 0-05, onetailed test). The percentage of GHQ cases among subjects with EPQ-L scores above the median was 15 %, whereas among subjects with EPQ-L scores below the median the percentage of GHQ cases was 28 %. However, this difference in the relative frequencies of GHQ cases and normals in the above-median and below-median EPQ-L groups did not reach significance (x 2 = 2-45, df = l.ns). Overall, therefore, the present results indicate that there is a negative relationship between EPQ-L and GHQ-Total scores over the entire range of GHQ scores, but that social desirability effects are not statistically significant when the GHQ is used for case identification purposes. Defensiveness shows a more marked relationship to GHQ scores, ACL-Df being significantly negatively correlated with GHQ-Total and GHQ cases having significantly lower mean ACL-Df scores than normals. Correlations of EPQ-L and ACL-Df with GHQ and MHQ subscales The correlations of EPQ-L and ACL-Df with the GHQ subscales (anxiety and insomnia, somatic symptoms, social dysfunction and severe depression) and with the MHQ subscales (anxiety, somatic symptoms, depression, obsessional state and obsessional personality) are shown in Table 1. In general, the GHQ and the MHQ show a similar pattern of subscale correlations with EPQ-L and with ACL-Df. The main points of interest can be summarized as follows: (i) ACL-Df was significantly negatively correlated with each of the MHQ symptom subscales, except the somatic symptom subscale which showed a small and non-significant correlation. The 3 significant subscale correlations were similar in magnitude to each other and to the overall MHQ-Total correlation. The pattern of correlation of the GHQ subscales with ACL- Df was closely similar to that for the MHQ subscales. In particular, the somatic symptom subscale again showed only a small and nonsignificant correlation. (ii) The obsessional personality measure of the MHQ was significantly positively correlated with ACL-Df. (iii) EPQ-L showed small and non-significant negative correlations with all the MHQ symptom subscales and with all the GHQ subscales, Table 1. Kendall's tau correlations of GHQ and MHQ subscales with EPQ-L and ACL-Df Correlation with Correlation with GHQ subscales EPQ-L ACL-Df MHQ subscales EPQ-L ACL-Df Anxiety and insomnia Somatic Severe depression Social dysfunction Subscale total (28 items) GHQ-Total (60 items) -008-013 -004-0-20* -017* -016* -002-0-21* -0-23** Anxiety Somatic Depression Obsessional state Obsessional! personality MHQ-Total -010-001 -009-008 + 010-009 -019* -007 + 0-27** -0-19** * P < 005; * P < 001. t This subscale is not included in the MHQ-Total.

740 K. R. Parkes except social dysfunction which was significantly negatively correlated with EPQ-L. (iv) The total score for the 28-item subset, which forms the scaled version of the GHQ, showed correlations with EPQ-L and with ACL- Df which were very similar in magnitude to those for the GHQ-Total (60 items). DISCUSSION The subjects and the conditions of assessment in the present study differed from those reported by Goldberg (1972), and the results obtained are consistent with the view that normal subjects assessed in an occupational context for research purposes would be expected to show a more marked negative relationship between social desirability and GHQ scores than patients assessed in a medical setting. Thus in the present work social desirability showed an overall significant negative correlation with GHQ-Total scores, and with the 28-item subscale total. However, examination of the individual GHQ subscale correlations with EPQ-L showed that the only significant value was that for the social dysfunction subscale. This subscale consists of items relating to social, interpersonal and occupational difficulties. It is consistent with the circumstances under which the present data were collected that difficulties of this nature would have been perceived as particularly socially undesirable, since the subjects were new entrants to the nursing profession who would be expected to cope successfully with difficult interpersonal and occupational demands. The magnitude of the negative correlation of this subscale with EPQ-L accounts largely for the overall significant relationship with the GHQ-Total. This suggests that the difference between the present findings and those of Goldberg (1972) may represent not only a difference between a normal and a patient group, but also a more specific social desirability bias, related to the particular conditions of assessment in the present study, and primarily affecting social dysfunction items. This would also explain the absence of a significant correlation of EPQ-L with the MHQ-Total, since there is no counterpart to the GHQ social dysfunction subscale among the MHQ items. The correlations of the GHQ-Total, the GHQ 28-item subset, and the MHQ-Total scores with ACL-Df were significant and similar in magnitude. Thus individuals high in defensiveness tend to report less psychiatric distress and this effect is not dependent on the precise nature of the questionnaire. The relationship between ACL-Df and the individual GHQ and MHQ subscales showed a consistent pattern of significant, negative correlations with all the symptom subscales of both the GHQ and the MHQ, excepting somatic symptoms for which the correlations were small and non-significant. High defensiveness is therefore associated with lower scores on scales concerned with psychological distress, such as anxiety or depression, but not on somatic symptom subscales. The most likely explanation of this is that somatic symptoms are commonly perceived as physical rather than mental in origin, and therefore do not imply the psychological vulnerability that the defensive individual is reluctant to acknowledge, but it is also possible that psychological distress can be more readily suppressed by a defensive individual, whereas somatic symptoms may be more difficult to ignore. In contrast to the other MHQ subscales, the correlation of the MHQ measure of obsessional personality traits with ACL-Df was positive and highly significant. Thus defensive individuals not only 'eliminate the negative' but also 'accentuate the positive', in that they tend to endorse characteristics such as conscientiousness and perfectionism, which they perceive as favourable. The overall correlation between ACL-Df and EPQ-L confirmed other findings of a significant, although not large, positive relationship between measures of defensiveness and social desirability (Gough &Heilbrun, 1965; Strickland & Crowne, 1963), but of greater interest in the present work was the markedly different pattern of correlations of these variables with the GHQ and MHQ subscales. As noted above, the effect of social desirability was limited to one specific subscale, GHQ social dysfunction, to which the subjects could be expected to show particular sensitivity in the circumstances under which the data were collected. The other GHQ and MHQ subscales did not show social desirability effects. However, the effects of defensiveness were nonspecific, that is, all the different symptom categories (with the exception of somatic symptoms) were affected to approximately the same extent. These results are in accordance with the view

Social desirability, defensiveness and psychiatric inventory scores 741 that defensiveness is associated with an internal need to preserve self-esteem and therefore affects the reporting of all psychological distress, irrespective of whether or not it has particular salience in relation to the situation in which the assessment is carried out; whereas social desirability effects are mediated by situational factors, and in the circumstances of the present study only social dysfunction was perceived as conflicting with need for approval. The findings discussed above considerably extend the information previously available about the effects of social desirability and defensiveness on self-report psychiatric inventory scores, but it should be noted that the present data were obtained from female subjects, and the results would not necessarily apply to males. Male subjects typically report lower levels of psychiatric symptomatology on selfreport inventories (for instance, Goldberg, 1972; Crisp et al. 1978; Finlay-Jones & Burvill, 1977), and this may reflect not only genuine differences between males and females in their experience of psychiatric symptoms, but also differences in the ways in which scores are influenced by social desirability and defensiveness. In the present study no clinical assessments could be made of the subjects' degree of psychiatric disturbance. Comparison of psychiatric inventory scores and clinical ratings based on interview assessments would allow further examination of the effects of social desirability and defensiveness on the reporting of psychiatric symptoms. Although the tendency to conceal or deny psychiatric disturbance in an interview may be greater than in responding to a pencil-and-paper questionnaire, it is more difficult for a subject to do so in a face-to-face situation. 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