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Verbal hallucinations in normals—III: Dysfunctional personality correlates
Person. individ. DiB: Vol. 16, No. 1, pp. 5762, Printed in Great Britain. All rights reserved
0191-8869/94 56.00 + O.OLl Copyright 0 1993 Pergamon Press Ltd
1994
VERBAL HALLUCINATIONS IN NORMALS-III: DYSFUNCTIONAL PERSONALITY CORRELATES TERRY R. BARRETT’* and JANE B. ETHERIDGE* ‘Psychology Department and 2Counseling and Testing Center, Murray State University, Murray, KY 42071, U.S.A. (Received 31 March
1993)
Summary-Two studies are reported designed to assess the relationship of verbal hallucinations reported by individuals in the general population to dysfunctional personality characteristics measured by Millon’s Clinical Multiaxial Inventory (MCMI). In both studies, hallucinators and non-hallucinators were selected based on scores from the Verbal Hallucination Questionnaire and given the MCMI. The pattern of results obtained in both studies suggest that verbal hallucinators experience heightened negative affect and may have heightened feelings of rejection and incompetence in social situations compared to non-hallucinators.
Several recent studies suggest that verbal hallucinations are sometimes experienced by individuals in the general population in an otherwise normal state of consciousness (e.g. Barrett & Etheridge, 1992; Bentall & Slade, 1985; Posey & Losch, 1983; Young, Bentall, Slade & Dewey, 1986). In the first study ever conducted to specifically examine the prevalence of verbal hallucinations in the general population, Posey and Losch (1983) constructed a verbal hallucination questionnaire. This questionnaire consisted of several examples of verbal hallucination experiences reported by individuals in the community. These authors found that 71% of 375 college students reported having had at least one verbal hallucination. Barrett and Etheridge (1992) replicated and extended these findings. We found, for example, that 37.2% of 586 college students reported Schneider’s (1959) first rank schizophrenic symptom of hearing one’s own thoughts aloud, outside their head, when no one was present. Even more surprising, we found that 71.4% of those reporting such an experience indicated that this occurred at least once a month. In fact, 47% said this experience occurred at least once a week. Bentall and Slade (1985) and Young et al. (1986) have both reported a similar incidence in British college students.? One possible explanation for these results is that Ss reporting verbal hallucinations are not reporting conscious experiences. Rather they might be tailoring their responses in ways they perceive to be socially desirable for this particular experimental situation. Barrett and Etheridge (1992) tested verbal hallucinators and non-hallucinators on five measures of social desirability. They found that reports of verbal hallucinations were not related to these measures of experimental reactivity. In addition, Barrett (1993) found that verbal hallucinators and non-hallucinators did not differentially respond to demand characteristics in an imagery rating task. Based on the above findings, we have come to the working hypothesis that Ss in the general population who report verbal hallucinations are, for the most part, telling us the truth about conscious events they have experienced. The present set of studies explores the hypothesis that individuals in the general population who experience verbal hallucinations also exhibit relatively unstable emotional tendencies. There is good reason for pursuing this line of investigation. Many in the mental health community believe the association between hallucinations, particularly verbal hallucinations, and psychopathology is strong (Kaplan & Sadock, 1985; Sarbin, 1970). For example, the DSM III-R (American Psychiatric Association, 1987) specifically includes verbal hallucinations as an important marker of Schizo-
*To whom requests for reprints should be addressed. tin both of these studies, Ss were asked to respond to the item “I often hear a voice speaking my own thoughts aloud.” Approximately 15% of their Ss responded positively. This is quite comparable to the percentage of students in the present study who rated hearing their own thoughts aloud as occurring at least once a week. 57
58
TERRY R. BARRETTand JANEB. ETHERIDGE
phrenia. In fact, the correlation between psychopathology and verbal hallucinations has led Junginger and Frame (1985) to suggest that verbal hallucinations, in the absence of other features of psychopathology, may indicate the presence of emotional problems. The evidence relevant to the relationship of unstable emotionality and verbal hallucinations in the general population, however, is mixed. Posey and Losch (1983) asked 20 individuals who reported a variety of verbal hallucinations to complete the Minnesota Multiphasic Personality Inventory (MMPI) (Hathaway & McKinley, 1967). An inspection of the resulting MMPI profiles did not indicate the presence of emotional problems. Barrett and Etheridge (1992) compared 24 hallucinators and 24 non-hallucinators on the MMPI and the XL-90-R (Derogatis, 1983). The two groups did not differ on any of the standard MMPI or SCL-90-R scales. On the other hand, at least one study has found a relationship between emotional instability and reports of hallucinations in the general population. Young et al. (1986) reported a significant correlation in college students between the Neuroticism scale of the Eysenck Personality Questionnaire (Eysenck & Eysenck, 1976) and scores on the Launay-Slade Hallucination Scale (Launey & Slade, 198 1). This pattern of results suggests the possibility that verbal hallucinations, reported by individuals in the general population, are related to emotional instability specifically associated with dysfunctional personality characteristics that are tapped by the Eysenck Personality Questionnaire but are not measured by the MMPI and the SCL-90-R. One way to test this idea would be to test hallucinators and non-hallucinators on an independent measure specifically designed to measure dysfunctional personality characteristics. Such a measure was introduced by Millon (1983). This instrument, called the Millon Clinical Multiaxial Inventory (MCMI), is based on a well-articulated theory of personality. Wetzler (1990) has suggested that the MCMI is quite sensitive to personality features indicative of unstable emotionality. The present paper presents the results of two studies designed to assess the relation between verbal hallucinations and dysfunctional personality characteristics among individuals in the general population. The hypothesis being tested in both studies was that individuals in the general population reporting frequent verbal hallucinations would show heightened indications of emotional instability on the MCMI compared to non-hallucinators.
METHOD
Subjects The Ss for Study 1 were 128 college students from introductory psychology classes who completed the Verbal Hallucination Questionnaire (Barrett & Etheridge, 1992) and the MCMI (Millon, 1983). Using criteria specified by Barrett and Etheridge (1992), two groups were selected for analysis. Hallucinators were defined as those in the top 15% of individuals most frequently reporting verbal hallucinations. Non-hallucinators were defined as those who reported never having experienced a verbal hallucination. This produced 18 hallucinators (14% of the original sample) and 28 non-hallucinators (22% of the original sample). The Ss for Study 2 were 18 hallucinators and 18 non-hallucinators randomly selected from a large pool of college students from introductory psychology classes (different from the pool used in Study 1). The same criteria as used in Study 1 were used to select hallucinators and non-hallucinators. Table 1 shows the mean age, mean ACT composite scores, and the ratio of males to females for hallucinators and non-hallucinators in each of the two studies. Analyses of variance with Groups (hallucinators vs non-hallucinators) as the grouping variable produced no significant differences in age or ACT composite in either study. Chi-square analyses with groups (hallucinators vs non-hallucinators) and Sex (male vs female) as the independent variables indicated no differential distribution of males to females across hallucinators and non-hallucinators in either study. Materials Verbal Hallucination Questionnaire. The Verbal Hallucination Qustionnaire (Barrett & Etheridge, 1992) is a modified version of the hallucination questionnaire constructed by Posey and Losch (1983). The version we used consisted of 13 descriptions of verbal hallucination experiences. Ss were asked to indicate whether they had ever had an experience similar to the one described.
Verbal
hallucinations-III
59
If Ss answered in the affirmative, they were asked to write a description of that experience and rate how often they had such experiences on a seven point scale. Millon Clinical Multiaxial Inventory (MCMZ). The MCMI (Millon, 1983) consists of 175 items. Ss were asked to mark items as either true for them or false for them. Procedure
The Ss in Study 1 were run in small groups that never exceeded 15 individuals. After they finished the verbal hallucination questionnaire, Ss were given a short filler task and then asked to complete a long series of true-false questions that included all of the MCMI items randomly distributed among 80 distractor items. The Ss in Study 2 completed the Verbal Hallucination Questionnaire as in Study 1 and then left the laboratory. They were then recalled to the laboratory individually and asked to complete the questionnaire containing the MCMI. At the time the Ss in Study 2 completed the MCMI, the experimenter who administered the questionnaire was blind to group membership. RESULTS
AND DISCUSSION
For both studies, the MCMI was scored in accordance with standard procedures to yield 20 scale scores. For each scale, higher scores are more reflective of emotional problems. No questionnaire in either study was judged invalid using the criteria provided by Millon (1983). In each study, we did two series of 20 two-group analyses of variance (one for each of the MCMI content scales). The grouping variable was Groups (hallucinators vs non-hallucinators) and the dependent variable for the first series was the MCMI raw scores. The dependent variable for the second series was the MCMI base rate score for the first eight scales and the adjusted base rate score for the remaining 12 scales. In both studies, the raw score analyses and the base rate analyses yielded similar results. Consequently, only the base rate analyses will be reported. Table 2 (Study 1) and Table 3 (Study 2) show the base rate means for the basic personality pattern scales (1 through 8), and the adjusted base rate means for the three pathological personality disorder scales (9, 10, and 11) and for the clinical symptom syndrome scales (12 through 20) separately for hallucinators and non-hallucinators. Table 4 summarizes the results of the analyses of variance for both studies. The numbers in the column labelled Study 1 are the Fvalues with 1 and 44 dfthat were significant at P < 0.05 produced in Study 1. Looking at this column, you can see there were 11 scales that produced significant differences between hallucinators and non-hallucinators. As is indicated in Table 2, in each of these except scale 7, hallucinators scored higher than non-hallucinators. On scale 7, hallucinators scored lower than non-hallucinators. The column labelled Study 2 in Table 4 shows F values with 1 and 34 df at P < 0.05 produced in Study 2. There were eight significant differences produced. In each of these, hallucinators had higher scores than non-hallucinators. Table
I. Means and standard deviations for age and ACT and number of males and females in Study I and 2 Hallucinators
Characteristics
N
ACT composite
Total
ACT composite Gender Males Females
Total
N
Study I 19.56 (1.62) 18.19 (5.43)
Age Gender Males Females
Mean (SD)
Non-hallucinators
8 IO 18
Study 2 19.06 (1.00)
20.75 (3.19) 17.95 (4.05) 12 16 28 20.06 (1.51)
19.53 (3.70) 6 12 18
Mean (SD)
19.06 (4.37) 4 14 18
TERRY R. BARRETT and JANE B. ETHERIDGE
60 Table 2. MCMI
base rate means and standard
deviations
in Studv
I
Table 3. MCMI base rate means and standard
Mean (SD)
SC&S
I. 2. 3. 4. 5. 6. 7. 8. 9. 10. I 1. 12. 13. 14. 15. 16. 17. 18. 19. 20.
Asocial Avoidant Submissive Gregarious Narcissistic Aggressive Conforming Negativistic Schizoid Cycloid Paranoid Anxiety Somatoform Hypomanic Dysthymic Alcohol Abuse Drug Abuse Psychotic Thinking Psvchotic Demession P&hotic D&ions
44.06 63.61 78.22 60.89 57.44 54.94 50.78 64.89 56.44 67.39 68.44 79.67 74.61 65.00 74.33 60.61 63.11 59.94 63.33 63.94
(25.48) (23.68) (25.07) (26.34) (22.06) (25.22) (13.28) (25.23) (9.57) (17.53) (9.28) (27.16) (17.46) (22.56) (26.27) (17.55) (15.64) (8.54) (IO.551 i12.26j
Mean (SD)
Scales
Mean (SD) 34.39 40.10 61.36 70.89 68.21 59.50 61.00 46.82 41.43 49.93 62.96 63.32 64.79 53.71 56.57 49.18 56.25 51.04 46.18 56.57
deviations
in Study 2
Non-hallucinators
Non-hallucinators
I. 2. 3. 4. 5. 6. 7. 8. 9. 10.
(27.82) (28.21) (25.08) (19.35) (21.69) (18.01) (16.65) (30.12) (18.70) (17.87) (15.30) (26.09) (15.41) (29.07) (24.20) (18.19) (23.23) (12.79) (17.701 il9.45j
I I. 12. 13. 14. 15. 16. 17. 18. 19. 20.
Asocial Avoidant Submissive Gregarious Narcissistic Aggressive Conforming Negativistic Schizoid Cycloid Paranoid Anxiety Somatoform Hypomanic Dysthymic Alcohol Abuse Drug Abuse Psychotic Thinking Psvchotic Deoression Psichotic D&ions
40.83 58.28 76.56 63.00 64.78 48.78 55.67 62.83 55.11 63.11 69.22 78.00 76.83 73.17 71.39 60.17 64.56 59.78 57.94 64.50
(32.60) (30.35) (28.14) (32.79) (26.46) (22.57) (15.39) (24.64) (19.22) (19.10) (10.50) (29.99) (18.24) (17.79) (30.00) (16.87) (12.25) (12.65) (13.11) i7.66)’
Mean (SDI 31.89 34.89 56.83 70.78 72.39 61.78 63.11 39.44 44.11 50.89 63.06 57.33 66.28 51.61 54.83 45.50 55.56 50.61 45.83 59.39
(21.72) (25.03) (27.27) (27.41) (22.73) (16.48) (14.63) (18.24) (17.42) (17.64) (14.22) (25.19) (17.65) (36.03) (21.91) (15.44) (26.24) (10.17) (15.221 i13.04j
The next column in Table 4 indicates the replication rate from Study 1 to 2. When the scale was significant in Study 1, that scale had to be significant in Study 2 and the means in both studies had to be in the same direction in order for it to be called a replication. When the scale was not significant in Study 1, that scale could not be significant in Study 2 for it to be counted as a replication. You can see that of the 11 scales that produced significant results in Study 1, seven of them produced significant mean differences in the same direction in Study 2 (scales 2, 3, 8, 12, 16, 18, and 19). The four exceptions were scales 7, 9, 10, and 15. However in each of these cases, the pattern of means was the same in Study 1 and 2. In addition, for three of these four scales (9, 10, and 15) the probability that the F occurred by chance in Study 2 was < 0.10. You can also see that of the nine scales in Study 1 that failed to produce significant differences, eight of them also failed to produce significant results in Study 2 (scales 1, 4, 5, 6, 11, 13, 17, and 20). The only scale that produced significant results in Study 2 but not in Study 1 was scale 14. Hallucinators scored significantly higher than non-hallucinators on this scale. Aithough this scale differed in terms of significance in Study 1 and 2, the pattern of means for hallucinators and non-hallucinators were the same in the two studies. The results of these two studies provide strong evidence that hallucinators and non-hallucinators differ significantly on seven of the MCMI scales (2, 3, 8, 12, 16, 18, and 19). The evidence is also clear that hallucinators and non-hallucinators do not differ on eight of the MCMI scales (1, 4, 5, Table 4. Summary
Scales I. 2. 3. 4. 5. 6. 7. 8. 9. 10.
I I. 12. 13. 14. 15. 16. 17. 18. 19. 20.
Asocial Avoidant Submissive Gregarious Narcissistic Aggressive Conforming Negativistic Schizoid Cycloid Paranoid Anxiety Somatoform Hypomanic Dysthymic Alcohol Abuse Drug Abuse Psychotic Thinking Psychotic Depression Psychotic Delusions
of ANOVAs
completed
Study I Study 2 F( 1,44) W,34) P < 0.05 P < 0.05
in Studies
Reulication **
8.58 4.96
4.81 4.46 9.88 10.62 4.17
I
6.36 4.56
** ** ** ** **
8.98
I*
5.01
t. **
I.
5.18 5.52 4.44
7.41
II **
6.76 13.71
5.74 6.55
l
* ** l*
and 2 Factor loading +F3 +Fl +F4 -F3 +F2 -F4 -FI +FI +FI +Fl fF2 +Fl +Fl +Fl +Fl +F4 -F4 +FI +FI +F2
Verbal hallucinations-III
61
6, 11, 13, 17, and 20). The data is not quite so clear on the other five scales (7, 9, 10, 14, and 15). On these scales, only one of the two studies produced a significant result. On the other hand, the pattern of mean differences for these five scales was similar in the two studies. In fact for three of these five scales (9, 10, and 15), the non-significant F value in Study 2 approached significance (P < 0.10). All of these considerations, taken together, suggest that the results of Study 1 and 2 are quite similar. One of the problems associated with the MCMI is the considerable item overlap from scale to scale. Since the scales are not independent of one another, interpreting each of the significant differences between hallucinators and non-hallucinators as a se,parate and independent finding may not be warranted. A more reasonable way to understand these results might be to consider them in light of factor analyses that have been performed on the MCMI (see Wetzler, 1990 for a brief review). We decided to use the factor structure reported by Millon (1983) as a reference because of research reported by Helmes (1989). He found the degree of co h gruence between the factor solution presented by Millon (1983) and other published factor analy$es of the MCMI to be quite good. The last column in Table 4 summarizes important aspects of the factor structure reported by Millon (1983) for the MCMI. For each scale, it shows the factor (Fl, F2, F3, or F4) on which the scale had its highest loading. It also indicates the sign of the factor loading. As you can see, of the seven scales that produced the same significant results in both studies, five of them load on Factor 1 (scales 2,8, 12, 18, and 19) and the other two load on Factor 4 (scales 3 and 16). The five scales that produced similar patterns of means and a significant difference in one of the two studies (scales 7, 9, 10, 14, and 15) all loaded on Factor 1. Overall, 10 of the 11 scales that load highest on Factor 1 and two of the four scales that load highest on Factor 4 produced similar patterns of means and a significant difference in, at least, one of the two studies. None of the scales that loaded on Factor 2 or Factor 3 produced any significant effects.
SUMMARY
AND CONCLUSIONS
All of the results indicate clearly that hallucinators score higher than non-hallucinators on Factor 1. According to Millon (1983) those scoring high on Factor 1 can be characterized as showing more “depressive and labile emotionality expressed in affective moodiness and neurotic complaint” (p. 49). In addition, there is some indication that hallucinators also scored higher on Factor 4.* Millon (1983) has argued that those who score high on Factor 4 tend to show “. . . social constraint and conformity as opposed to social aggression and rebellious behavior” (p. 50). These considerations suggest the hypothesis that hallucinators and non-hallucinators differ along one, and possibly two, fundamental personality dimensions. One dimension is emotional in nature (Factor 1) while the other is social in nature (Factor 4). Emotionally, one might characterize hallucinators compared to non-hallucinators as being more depressed, anxious, and not satisfied with their life. Their self-image might be characterized as one in which they feel relatively misunderstood and unappreciated which leads to feelings of isolation and rejection by others. Socially, hallucinators might be described as more passive and submissive than non-hallucinators. They may be more afraid of social conflict because they see themselves as relatively powerless and , incompetent. This sort of hypothesized mix of negative affect and feelings of social isolation and incompetence suggests that verbal hallucinators will, over the course of their life, be more likely than non-hallucinators to experience serious behavioral, cognitive, and/or emotional problems for which professional help might be necessary. If this hypothesis is correct, it suggests that the presence of verbal hallucinations in young adulthood could be used as an early indicator of such problems. This hypothesis is similar to that proposed by Junginger and Frame (1985). Another hypothesis we would like to suggest is that the cognitive mechanisms responsible for verbal hallucinations may be shaped by the same constellation of genetic, environmental, and *Millon’s Factor IV has not been consistently replicated in other studies. In fact, analyses conducted by Helmes (1989) suggested that of the 10 studies he compared, only four of them suggested that Factor IV should be retained. Consequently, we suggest that caution be used in interpreting our results regarding Millon’s Factor IV.
62
TERRYR. BARRETT and JANE B. ETHERIDGE
psychological factors that determine certain styles of behaving, understanding, and relating to others; that is, forces that mould relatively dysfunctional patterns of personality. In particular, we would suggest that verbal hallucinators may have grown up in relatively negative family environments. It is generally presumed that dysfunctional family interactions are a major contributing factor to disorders of personality (Millon, 1981). In addition, there is some evidence that, at least, one dysfunctional family interaction during childhood, sexual abuse, may be predictive of hallucinations during adulthood (Ellenson, 1986). Just how those family interactions might lead to the set of cognitive mechanisms responsible for verbal hallucinations, however, has not yet been seriously investigated. Acknowledgements-The from the Committee
research reported here was supported by Grant 2-12869 and Grant on Institutional Studies and Research at Murray State University.
2-12901
to the first author
REFERENCES American Psychiatric Association (1987). Diagnostic and statistical manual of mental disorders (3rd Edn Revised). Washington, DC: Author. Barrett, T. R. (1993). Verbal hallucinations in normals-II: self-report imagery vividness. Personality and Individual Differences, 15, 6167. Barrett, T. R. & Etheridge, J. B. (1992). Verbal hallucinations in normals, I: People who hear “voices.” Applied Cognitive Psychology, 6, 379-387. Bentall, R. P. & Slade, P. D. (1985). Reliability of a scale measuring disposition towards hallucinations: A brief report. Personality and Individual Differences, 6, 527-529. Derogatis, L. R. (1983). XL-90-R: Administration, scoring and procedures manual. Towson, MD: Clinical Psychometric Research. Ellenson, G. S. (1986). Disturbances of perception in adult female incest survivors. Social Casework: Journal of Contemporary Social Work, 67, 149-159. Eysenck, H. J. & Eysenck, S. B. G. (1976). Psychoticism as a dimension of personality. London: Hodder & Stoughton. Hathaway, S. R. &McKinley, J. C. (1967). Minnesota Multiphasic Personality 1nventory:Manual (Revised 1967). New York: The Psychological Corp. Helmes, E. (1989). Stability of the internal structure of the Millon Clinical Multiaxial Inventory. Journal of Psychopathology and Behavioral Assessment, II, 327-338. Junginger, J. & Frame, C. L. (1985). Self-report of the frequency and phenomenology of verbal hallucinations. The Journal of Nervous and Mental Disease, 173, 149-l 55. Kaplan, H. I. & Sadock, B. J. (1985). Modern synopsis of the comprehensive textbook of psychiatry/IV. Baltimore, MD: Williams and Wilkins. Launay, G. & Slade, P. (1981). The measurement of hallucinatory predisposition in male and female prisoners. Personality and Individual Differences, 2, 221-234. Millon, T. (1981). Disorders of personality. DSM-III: Axis II. New York: Wiley. Millon, T. (1983). Millon Clinical Multiaxial Inventory (3rd Edn). Minneapolis: Interpretive Scoring Systems. Posey, T. B. & Losch, M. E. (1983). Auditory hallucinations of hearing voices in 375 normal subjects. Imagination, Cognition and Personality, 3, 99-l 13. Sarbin, T. R. (1970). The concept of hallucination. Journal of Personality, 35, 359-380. Schneider, K. (1959). Clinicalpsychopathology. (Translated by Hamilton, M. W.). New York: Grune & Stratton. (Original work published in 1959.) Wetzler, S. (1990). The Millon clinical Multiaxial Inventory (MCMI): A review. Journal of Personality Assessment, 55, 445464. Young, H. F., Bentall, R. P., Slade, P. D. & Dewey, M. E. (1986). Disposition towards hallucination, gender and IQ scores. Personality and Individual Differences, 7, 247-249.
0191-8869/94 56.00 + O.OLl Copyright 0 1993 Pergamon Press Ltd
1994
VERBAL HALLUCINATIONS IN NORMALS-III: DYSFUNCTIONAL PERSONALITY CORRELATES TERRY R. BARRETT’* and JANE B. ETHERIDGE* ‘Psychology Department and 2Counseling and Testing Center, Murray State University, Murray, KY 42071, U.S.A. (Received 31 March
1993)
Summary-Two studies are reported designed to assess the relationship of verbal hallucinations reported by individuals in the general population to dysfunctional personality characteristics measured by Millon’s Clinical Multiaxial Inventory (MCMI). In both studies, hallucinators and non-hallucinators were selected based on scores from the Verbal Hallucination Questionnaire and given the MCMI. The pattern of results obtained in both studies suggest that verbal hallucinators experience heightened negative affect and may have heightened feelings of rejection and incompetence in social situations compared to non-hallucinators.
Several recent studies suggest that verbal hallucinations are sometimes experienced by individuals in the general population in an otherwise normal state of consciousness (e.g. Barrett & Etheridge, 1992; Bentall & Slade, 1985; Posey & Losch, 1983; Young, Bentall, Slade & Dewey, 1986). In the first study ever conducted to specifically examine the prevalence of verbal hallucinations in the general population, Posey and Losch (1983) constructed a verbal hallucination questionnaire. This questionnaire consisted of several examples of verbal hallucination experiences reported by individuals in the community. These authors found that 71% of 375 college students reported having had at least one verbal hallucination. Barrett and Etheridge (1992) replicated and extended these findings. We found, for example, that 37.2% of 586 college students reported Schneider’s (1959) first rank schizophrenic symptom of hearing one’s own thoughts aloud, outside their head, when no one was present. Even more surprising, we found that 71.4% of those reporting such an experience indicated that this occurred at least once a month. In fact, 47% said this experience occurred at least once a week. Bentall and Slade (1985) and Young et al. (1986) have both reported a similar incidence in British college students.? One possible explanation for these results is that Ss reporting verbal hallucinations are not reporting conscious experiences. Rather they might be tailoring their responses in ways they perceive to be socially desirable for this particular experimental situation. Barrett and Etheridge (1992) tested verbal hallucinators and non-hallucinators on five measures of social desirability. They found that reports of verbal hallucinations were not related to these measures of experimental reactivity. In addition, Barrett (1993) found that verbal hallucinators and non-hallucinators did not differentially respond to demand characteristics in an imagery rating task. Based on the above findings, we have come to the working hypothesis that Ss in the general population who report verbal hallucinations are, for the most part, telling us the truth about conscious events they have experienced. The present set of studies explores the hypothesis that individuals in the general population who experience verbal hallucinations also exhibit relatively unstable emotional tendencies. There is good reason for pursuing this line of investigation. Many in the mental health community believe the association between hallucinations, particularly verbal hallucinations, and psychopathology is strong (Kaplan & Sadock, 1985; Sarbin, 1970). For example, the DSM III-R (American Psychiatric Association, 1987) specifically includes verbal hallucinations as an important marker of Schizo-
*To whom requests for reprints should be addressed. tin both of these studies, Ss were asked to respond to the item “I often hear a voice speaking my own thoughts aloud.” Approximately 15% of their Ss responded positively. This is quite comparable to the percentage of students in the present study who rated hearing their own thoughts aloud as occurring at least once a week. 57
58
TERRY R. BARRETTand JANEB. ETHERIDGE
phrenia. In fact, the correlation between psychopathology and verbal hallucinations has led Junginger and Frame (1985) to suggest that verbal hallucinations, in the absence of other features of psychopathology, may indicate the presence of emotional problems. The evidence relevant to the relationship of unstable emotionality and verbal hallucinations in the general population, however, is mixed. Posey and Losch (1983) asked 20 individuals who reported a variety of verbal hallucinations to complete the Minnesota Multiphasic Personality Inventory (MMPI) (Hathaway & McKinley, 1967). An inspection of the resulting MMPI profiles did not indicate the presence of emotional problems. Barrett and Etheridge (1992) compared 24 hallucinators and 24 non-hallucinators on the MMPI and the XL-90-R (Derogatis, 1983). The two groups did not differ on any of the standard MMPI or SCL-90-R scales. On the other hand, at least one study has found a relationship between emotional instability and reports of hallucinations in the general population. Young et al. (1986) reported a significant correlation in college students between the Neuroticism scale of the Eysenck Personality Questionnaire (Eysenck & Eysenck, 1976) and scores on the Launay-Slade Hallucination Scale (Launey & Slade, 198 1). This pattern of results suggests the possibility that verbal hallucinations, reported by individuals in the general population, are related to emotional instability specifically associated with dysfunctional personality characteristics that are tapped by the Eysenck Personality Questionnaire but are not measured by the MMPI and the SCL-90-R. One way to test this idea would be to test hallucinators and non-hallucinators on an independent measure specifically designed to measure dysfunctional personality characteristics. Such a measure was introduced by Millon (1983). This instrument, called the Millon Clinical Multiaxial Inventory (MCMI), is based on a well-articulated theory of personality. Wetzler (1990) has suggested that the MCMI is quite sensitive to personality features indicative of unstable emotionality. The present paper presents the results of two studies designed to assess the relation between verbal hallucinations and dysfunctional personality characteristics among individuals in the general population. The hypothesis being tested in both studies was that individuals in the general population reporting frequent verbal hallucinations would show heightened indications of emotional instability on the MCMI compared to non-hallucinators.
METHOD
Subjects The Ss for Study 1 were 128 college students from introductory psychology classes who completed the Verbal Hallucination Questionnaire (Barrett & Etheridge, 1992) and the MCMI (Millon, 1983). Using criteria specified by Barrett and Etheridge (1992), two groups were selected for analysis. Hallucinators were defined as those in the top 15% of individuals most frequently reporting verbal hallucinations. Non-hallucinators were defined as those who reported never having experienced a verbal hallucination. This produced 18 hallucinators (14% of the original sample) and 28 non-hallucinators (22% of the original sample). The Ss for Study 2 were 18 hallucinators and 18 non-hallucinators randomly selected from a large pool of college students from introductory psychology classes (different from the pool used in Study 1). The same criteria as used in Study 1 were used to select hallucinators and non-hallucinators. Table 1 shows the mean age, mean ACT composite scores, and the ratio of males to females for hallucinators and non-hallucinators in each of the two studies. Analyses of variance with Groups (hallucinators vs non-hallucinators) as the grouping variable produced no significant differences in age or ACT composite in either study. Chi-square analyses with groups (hallucinators vs non-hallucinators) and Sex (male vs female) as the independent variables indicated no differential distribution of males to females across hallucinators and non-hallucinators in either study. Materials Verbal Hallucination Questionnaire. The Verbal Hallucination Qustionnaire (Barrett & Etheridge, 1992) is a modified version of the hallucination questionnaire constructed by Posey and Losch (1983). The version we used consisted of 13 descriptions of verbal hallucination experiences. Ss were asked to indicate whether they had ever had an experience similar to the one described.
Verbal
hallucinations-III
59
If Ss answered in the affirmative, they were asked to write a description of that experience and rate how often they had such experiences on a seven point scale. Millon Clinical Multiaxial Inventory (MCMZ). The MCMI (Millon, 1983) consists of 175 items. Ss were asked to mark items as either true for them or false for them. Procedure
The Ss in Study 1 were run in small groups that never exceeded 15 individuals. After they finished the verbal hallucination questionnaire, Ss were given a short filler task and then asked to complete a long series of true-false questions that included all of the MCMI items randomly distributed among 80 distractor items. The Ss in Study 2 completed the Verbal Hallucination Questionnaire as in Study 1 and then left the laboratory. They were then recalled to the laboratory individually and asked to complete the questionnaire containing the MCMI. At the time the Ss in Study 2 completed the MCMI, the experimenter who administered the questionnaire was blind to group membership. RESULTS
AND DISCUSSION
For both studies, the MCMI was scored in accordance with standard procedures to yield 20 scale scores. For each scale, higher scores are more reflective of emotional problems. No questionnaire in either study was judged invalid using the criteria provided by Millon (1983). In each study, we did two series of 20 two-group analyses of variance (one for each of the MCMI content scales). The grouping variable was Groups (hallucinators vs non-hallucinators) and the dependent variable for the first series was the MCMI raw scores. The dependent variable for the second series was the MCMI base rate score for the first eight scales and the adjusted base rate score for the remaining 12 scales. In both studies, the raw score analyses and the base rate analyses yielded similar results. Consequently, only the base rate analyses will be reported. Table 2 (Study 1) and Table 3 (Study 2) show the base rate means for the basic personality pattern scales (1 through 8), and the adjusted base rate means for the three pathological personality disorder scales (9, 10, and 11) and for the clinical symptom syndrome scales (12 through 20) separately for hallucinators and non-hallucinators. Table 4 summarizes the results of the analyses of variance for both studies. The numbers in the column labelled Study 1 are the Fvalues with 1 and 44 dfthat were significant at P < 0.05 produced in Study 1. Looking at this column, you can see there were 11 scales that produced significant differences between hallucinators and non-hallucinators. As is indicated in Table 2, in each of these except scale 7, hallucinators scored higher than non-hallucinators. On scale 7, hallucinators scored lower than non-hallucinators. The column labelled Study 2 in Table 4 shows F values with 1 and 34 df at P < 0.05 produced in Study 2. There were eight significant differences produced. In each of these, hallucinators had higher scores than non-hallucinators. Table
I. Means and standard deviations for age and ACT and number of males and females in Study I and 2 Hallucinators
Characteristics
N
ACT composite
Total
ACT composite Gender Males Females
Total
N
Study I 19.56 (1.62) 18.19 (5.43)
Age Gender Males Females
Mean (SD)
Non-hallucinators
8 IO 18
Study 2 19.06 (1.00)
20.75 (3.19) 17.95 (4.05) 12 16 28 20.06 (1.51)
19.53 (3.70) 6 12 18
Mean (SD)
19.06 (4.37) 4 14 18
TERRY R. BARRETT and JANE B. ETHERIDGE
60 Table 2. MCMI
base rate means and standard
deviations
in Studv
I
Table 3. MCMI base rate means and standard
Mean (SD)
SC&S
I. 2. 3. 4. 5. 6. 7. 8. 9. 10. I 1. 12. 13. 14. 15. 16. 17. 18. 19. 20.
Asocial Avoidant Submissive Gregarious Narcissistic Aggressive Conforming Negativistic Schizoid Cycloid Paranoid Anxiety Somatoform Hypomanic Dysthymic Alcohol Abuse Drug Abuse Psychotic Thinking Psvchotic Demession P&hotic D&ions
44.06 63.61 78.22 60.89 57.44 54.94 50.78 64.89 56.44 67.39 68.44 79.67 74.61 65.00 74.33 60.61 63.11 59.94 63.33 63.94
(25.48) (23.68) (25.07) (26.34) (22.06) (25.22) (13.28) (25.23) (9.57) (17.53) (9.28) (27.16) (17.46) (22.56) (26.27) (17.55) (15.64) (8.54) (IO.551 i12.26j
Mean (SD)
Scales
Mean (SD) 34.39 40.10 61.36 70.89 68.21 59.50 61.00 46.82 41.43 49.93 62.96 63.32 64.79 53.71 56.57 49.18 56.25 51.04 46.18 56.57
deviations
in Study 2
Non-hallucinators
Non-hallucinators
I. 2. 3. 4. 5. 6. 7. 8. 9. 10.
(27.82) (28.21) (25.08) (19.35) (21.69) (18.01) (16.65) (30.12) (18.70) (17.87) (15.30) (26.09) (15.41) (29.07) (24.20) (18.19) (23.23) (12.79) (17.701 il9.45j
I I. 12. 13. 14. 15. 16. 17. 18. 19. 20.
Asocial Avoidant Submissive Gregarious Narcissistic Aggressive Conforming Negativistic Schizoid Cycloid Paranoid Anxiety Somatoform Hypomanic Dysthymic Alcohol Abuse Drug Abuse Psychotic Thinking Psvchotic Deoression Psichotic D&ions
40.83 58.28 76.56 63.00 64.78 48.78 55.67 62.83 55.11 63.11 69.22 78.00 76.83 73.17 71.39 60.17 64.56 59.78 57.94 64.50
(32.60) (30.35) (28.14) (32.79) (26.46) (22.57) (15.39) (24.64) (19.22) (19.10) (10.50) (29.99) (18.24) (17.79) (30.00) (16.87) (12.25) (12.65) (13.11) i7.66)’
Mean (SDI 31.89 34.89 56.83 70.78 72.39 61.78 63.11 39.44 44.11 50.89 63.06 57.33 66.28 51.61 54.83 45.50 55.56 50.61 45.83 59.39
(21.72) (25.03) (27.27) (27.41) (22.73) (16.48) (14.63) (18.24) (17.42) (17.64) (14.22) (25.19) (17.65) (36.03) (21.91) (15.44) (26.24) (10.17) (15.221 i13.04j
The next column in Table 4 indicates the replication rate from Study 1 to 2. When the scale was significant in Study 1, that scale had to be significant in Study 2 and the means in both studies had to be in the same direction in order for it to be called a replication. When the scale was not significant in Study 1, that scale could not be significant in Study 2 for it to be counted as a replication. You can see that of the 11 scales that produced significant results in Study 1, seven of them produced significant mean differences in the same direction in Study 2 (scales 2, 3, 8, 12, 16, 18, and 19). The four exceptions were scales 7, 9, 10, and 15. However in each of these cases, the pattern of means was the same in Study 1 and 2. In addition, for three of these four scales (9, 10, and 15) the probability that the F occurred by chance in Study 2 was < 0.10. You can also see that of the nine scales in Study 1 that failed to produce significant differences, eight of them also failed to produce significant results in Study 2 (scales 1, 4, 5, 6, 11, 13, 17, and 20). The only scale that produced significant results in Study 2 but not in Study 1 was scale 14. Hallucinators scored significantly higher than non-hallucinators on this scale. Aithough this scale differed in terms of significance in Study 1 and 2, the pattern of means for hallucinators and non-hallucinators were the same in the two studies. The results of these two studies provide strong evidence that hallucinators and non-hallucinators differ significantly on seven of the MCMI scales (2, 3, 8, 12, 16, 18, and 19). The evidence is also clear that hallucinators and non-hallucinators do not differ on eight of the MCMI scales (1, 4, 5, Table 4. Summary
Scales I. 2. 3. 4. 5. 6. 7. 8. 9. 10.
I I. 12. 13. 14. 15. 16. 17. 18. 19. 20.
Asocial Avoidant Submissive Gregarious Narcissistic Aggressive Conforming Negativistic Schizoid Cycloid Paranoid Anxiety Somatoform Hypomanic Dysthymic Alcohol Abuse Drug Abuse Psychotic Thinking Psychotic Depression Psychotic Delusions
of ANOVAs
completed
Study I Study 2 F( 1,44) W,34) P < 0.05 P < 0.05
in Studies
Reulication **
8.58 4.96
4.81 4.46 9.88 10.62 4.17
I
6.36 4.56
** ** ** ** **
8.98
I*
5.01
t. **
I.
5.18 5.52 4.44
7.41
II **
6.76 13.71
5.74 6.55
l
* ** l*
and 2 Factor loading +F3 +Fl +F4 -F3 +F2 -F4 -FI +FI +FI +Fl fF2 +Fl +Fl +Fl +Fl +F4 -F4 +FI +FI +F2
Verbal hallucinations-III
61
6, 11, 13, 17, and 20). The data is not quite so clear on the other five scales (7, 9, 10, 14, and 15). On these scales, only one of the two studies produced a significant result. On the other hand, the pattern of mean differences for these five scales was similar in the two studies. In fact for three of these five scales (9, 10, and 15), the non-significant F value in Study 2 approached significance (P < 0.10). All of these considerations, taken together, suggest that the results of Study 1 and 2 are quite similar. One of the problems associated with the MCMI is the considerable item overlap from scale to scale. Since the scales are not independent of one another, interpreting each of the significant differences between hallucinators and non-hallucinators as a se,parate and independent finding may not be warranted. A more reasonable way to understand these results might be to consider them in light of factor analyses that have been performed on the MCMI (see Wetzler, 1990 for a brief review). We decided to use the factor structure reported by Millon (1983) as a reference because of research reported by Helmes (1989). He found the degree of co h gruence between the factor solution presented by Millon (1983) and other published factor analy$es of the MCMI to be quite good. The last column in Table 4 summarizes important aspects of the factor structure reported by Millon (1983) for the MCMI. For each scale, it shows the factor (Fl, F2, F3, or F4) on which the scale had its highest loading. It also indicates the sign of the factor loading. As you can see, of the seven scales that produced the same significant results in both studies, five of them load on Factor 1 (scales 2,8, 12, 18, and 19) and the other two load on Factor 4 (scales 3 and 16). The five scales that produced similar patterns of means and a significant difference in one of the two studies (scales 7, 9, 10, 14, and 15) all loaded on Factor 1. Overall, 10 of the 11 scales that load highest on Factor 1 and two of the four scales that load highest on Factor 4 produced similar patterns of means and a significant difference in, at least, one of the two studies. None of the scales that loaded on Factor 2 or Factor 3 produced any significant effects.
SUMMARY
AND CONCLUSIONS
All of the results indicate clearly that hallucinators score higher than non-hallucinators on Factor 1. According to Millon (1983) those scoring high on Factor 1 can be characterized as showing more “depressive and labile emotionality expressed in affective moodiness and neurotic complaint” (p. 49). In addition, there is some indication that hallucinators also scored higher on Factor 4.* Millon (1983) has argued that those who score high on Factor 4 tend to show “. . . social constraint and conformity as opposed to social aggression and rebellious behavior” (p. 50). These considerations suggest the hypothesis that hallucinators and non-hallucinators differ along one, and possibly two, fundamental personality dimensions. One dimension is emotional in nature (Factor 1) while the other is social in nature (Factor 4). Emotionally, one might characterize hallucinators compared to non-hallucinators as being more depressed, anxious, and not satisfied with their life. Their self-image might be characterized as one in which they feel relatively misunderstood and unappreciated which leads to feelings of isolation and rejection by others. Socially, hallucinators might be described as more passive and submissive than non-hallucinators. They may be more afraid of social conflict because they see themselves as relatively powerless and , incompetent. This sort of hypothesized mix of negative affect and feelings of social isolation and incompetence suggests that verbal hallucinators will, over the course of their life, be more likely than non-hallucinators to experience serious behavioral, cognitive, and/or emotional problems for which professional help might be necessary. If this hypothesis is correct, it suggests that the presence of verbal hallucinations in young adulthood could be used as an early indicator of such problems. This hypothesis is similar to that proposed by Junginger and Frame (1985). Another hypothesis we would like to suggest is that the cognitive mechanisms responsible for verbal hallucinations may be shaped by the same constellation of genetic, environmental, and *Millon’s Factor IV has not been consistently replicated in other studies. In fact, analyses conducted by Helmes (1989) suggested that of the 10 studies he compared, only four of them suggested that Factor IV should be retained. Consequently, we suggest that caution be used in interpreting our results regarding Millon’s Factor IV.
62
TERRYR. BARRETT and JANE B. ETHERIDGE
psychological factors that determine certain styles of behaving, understanding, and relating to others; that is, forces that mould relatively dysfunctional patterns of personality. In particular, we would suggest that verbal hallucinators may have grown up in relatively negative family environments. It is generally presumed that dysfunctional family interactions are a major contributing factor to disorders of personality (Millon, 1981). In addition, there is some evidence that, at least, one dysfunctional family interaction during childhood, sexual abuse, may be predictive of hallucinations during adulthood (Ellenson, 1986). Just how those family interactions might lead to the set of cognitive mechanisms responsible for verbal hallucinations, however, has not yet been seriously investigated. Acknowledgements-The from the Committee
research reported here was supported by Grant 2-12869 and Grant on Institutional Studies and Research at Murray State University.
2-12901
to the first author
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