~ r y c h o l o ~ i c aReports, l 1976, 38, 1181-1182.
@ Psychological Reports 1976
STATE AND TRAIT CORRELATES OF SLEEP STAGES1 WILSE B. WEBB, MICHAEL H. BONNET University of Florida
A N D ROYCE M. W H I T E Man'rt
College
St~nzmury.-36 Ss completed a series of trait personality scales and rwo state scales immediately prior to sleeping in a sleep laboratory. Fewer significant correlations than would be expected by chance were found between scores on the state/trait measures and the stages of sleep as defined by the EEG. The stages of sleep, as defined by EEG criteria, have bccorne the standard descriptors of the sleep process. They have been shown ro be related to aspects of the sleep process such as the presence of dreams, sleep onset, and depth of sleep. Further, they have been found responsive to such variables as age, prior wakefulness, sleep length, and variations in sleep onset time. However, only limited explorations have been made of the relationship of the wide range of individual differences in sleep stages to personal characteristics. That is the concern of this paper. Thirty-six University of Florida undergraduates, aged 18 to 22 yr., spent one night in the sleep laboratory. They were given no prior instructions regarding their conduct during the previous day. Before the appointed experimental night, Ss completed five questionnaires related to personality trait variables including the Marlowe-Crowne Social Desirability Scale ( 2 ) , the Wiggins Social Introversion Scale ( 6 ) , the Zuckerman Sensation-seeking Scale ( 7 ) , the Spielberger Trait Anxiety Scale ( 5 ) , and the depression scale of the MMPI. Ss reported to the laboratory in groups of four (four males or four females in each group) at 1 0 p.m. They completed two state-variable scales: the Nowlis Mood Scale ( 3 ) as it applied to their day in general and the Spielberger State-Anxiety Scale. Electrode placements were made to record two channels of EEG and one channel of EOG. After Ss got into bed, they were given the Nowlis Mood Scale again, as it applied to that moment. Ss were then allowed 8 hr. of sleep. The sleep records were scored according to the method of Agnew and W e b b ( 1 ) . Besides stage amounts (Stage 0, 1, 2, 3, 4, and REM) several additional sleep measures such as latency to the various stages, the number of stage changes, alpha production, REM burst density, and the amount of Sragc 4 after 5 hr. of sleep were also recorded. There were six trait personal~tymeasures, 20 state personality measures, and I 5 within sleep measures. Pearson product-moment correlations and Spearman rank-order correlations were applied to the data to determine the relarion of sleep events to state and trait personality variables. An examination of the correlation matrices' ( 2 6 state and trait variables x 15 sleep measures) showed the following: ( a ) There were a total of 8 state personality measures which correlated significantly with the various sleep measures ( p = .05). About 20 significant correlations should have been found by chance alone. ( b ) An individual examination of each sleep measure showed that no sleep measure was correlated ( p = .05) with more than one state personality measure. At least one signifi'We gratefully acknowledge the support of NASA Grant N G R 10-005-057. 'The matrices are on file in Document NAPS-02777. Order from Microfiche Publications, 440 Park Avenue South, New York. N.Y. 10016. Remit $3.00 for microfiche or $6.00 for photocopy.
1182
W . B. WEBB, ET AL.
cant correlation would be expected by chance. ( c ) Only one correlation was significant ( p = . 0 1 ) . The amount of alpha produced prior to sleep onset correlated -.47 with the rating of "concentration at bed time." Four significant correlations would have been expected by chance. ( d ) N o trait variable was correlated significantly with any sleep event
( 9 = .05). Our conclusions are, of course, limited by the validity and range of out measures. W e recognize that the tests were not perfect and all aspects of personality were not assessed. However. they were the best we could find and were as broad ranging as possible. Sleep stages were measured as fully as possible. Also, since the completion o f our study, a srudy ( 4 ) relating various sleep measures to rhe Freiburg Personality Inventory has come to our attention. This inventory gives scores on 12 different personality traits including drpression, extraversion and several traits not measured in the present srudy. A casual glance at the correlation matrix of Schubert and Jovanovic indicates fewer correlations than would be expected by chance with no compelling pattern evident in the significant correlations. These results corroborate our trait personality findings with different measures and strengthen our conclusion that in normal healthy young adults individual differences in state or trait variables are not strong determinants of characteristics of sleep stage. W e must add a cautionary statement. W e are not saying that personality disturbances or extreme mood states have no effect on sleep. Anxieties, depressions, indeed elationsin either trait o r srate dimensions-can and do intrude on the sleep process. Any variable, whether internally or externally generated, that serves as a source of continuing engagement with the waking world ho!ds a potential threat for sweet sleep. W e are saying that our data indicate that, short of sharp deviations, our sleep stages are little determined by our personal states and traits. REFERENCES 1. AGNEW,H. W., JR.,6: WEBB,W. B. Sleep srage scoring. ]ournu/ Abstract Supplement of American Psychological Association, 1972, Manuscript No. 293. 2. CROWNE.D. P., & MARLOWE, D. A new scale of social desirability indcpendenr of psychopathology. Journal o f Conrrrlting Psychology, 1960, 24, 349-354. 3. NOWLIS,V. Research with rhe Mood Adjective Check List. I n S. S. Tomkins & C. E. Izard (Eds.), Affecs, cognijion, and personality. New York: Springer, 1965. Pp. 352-389. 4. SCHUBERT,F. C., & JOVANOVIC.U. J. Sleep behavior--especially falling asleep and awakenings during the night-in adults in relation to personality variables. In U. Jovanovic ( E d . ) , The nature o f d e e p . Stuttgart: Fischer, 1973. Pp. 123-126. C. D., GORSUCH,R. L., & LUSHENE,R. E. STAl manrial for the State5. SPIELBERCER, Tfait Anxiety Inventory. Palo Alto: Consulting Psychologists Press, 1970. 6. WIGGINS,J. S. Substantive dimensions of self-report in the MMPI item pool. Psychological Monographs, 1966, 80, No. 22 ( W h o l e No. 6 3 0 ) . 7. ZUCKERMAN,M., & LINK, K. Construct validity for the sensation-seeking scale. lourndl of Consulting and Clinical Psychology, 1968, 32, 420-426.
Accepted April 13, 1976.
@ Psychological Reports 1976
STATE AND TRAIT CORRELATES OF SLEEP STAGES1 WILSE B. WEBB, MICHAEL H. BONNET University of Florida
A N D ROYCE M. W H I T E Man'rt
College
St~nzmury.-36 Ss completed a series of trait personality scales and rwo state scales immediately prior to sleeping in a sleep laboratory. Fewer significant correlations than would be expected by chance were found between scores on the state/trait measures and the stages of sleep as defined by the EEG. The stages of sleep, as defined by EEG criteria, have bccorne the standard descriptors of the sleep process. They have been shown ro be related to aspects of the sleep process such as the presence of dreams, sleep onset, and depth of sleep. Further, they have been found responsive to such variables as age, prior wakefulness, sleep length, and variations in sleep onset time. However, only limited explorations have been made of the relationship of the wide range of individual differences in sleep stages to personal characteristics. That is the concern of this paper. Thirty-six University of Florida undergraduates, aged 18 to 22 yr., spent one night in the sleep laboratory. They were given no prior instructions regarding their conduct during the previous day. Before the appointed experimental night, Ss completed five questionnaires related to personality trait variables including the Marlowe-Crowne Social Desirability Scale ( 2 ) , the Wiggins Social Introversion Scale ( 6 ) , the Zuckerman Sensation-seeking Scale ( 7 ) , the Spielberger Trait Anxiety Scale ( 5 ) , and the depression scale of the MMPI. Ss reported to the laboratory in groups of four (four males or four females in each group) at 1 0 p.m. They completed two state-variable scales: the Nowlis Mood Scale ( 3 ) as it applied to their day in general and the Spielberger State-Anxiety Scale. Electrode placements were made to record two channels of EEG and one channel of EOG. After Ss got into bed, they were given the Nowlis Mood Scale again, as it applied to that moment. Ss were then allowed 8 hr. of sleep. The sleep records were scored according to the method of Agnew and W e b b ( 1 ) . Besides stage amounts (Stage 0, 1, 2, 3, 4, and REM) several additional sleep measures such as latency to the various stages, the number of stage changes, alpha production, REM burst density, and the amount of Sragc 4 after 5 hr. of sleep were also recorded. There were six trait personal~tymeasures, 20 state personality measures, and I 5 within sleep measures. Pearson product-moment correlations and Spearman rank-order correlations were applied to the data to determine the relarion of sleep events to state and trait personality variables. An examination of the correlation matrices' ( 2 6 state and trait variables x 15 sleep measures) showed the following: ( a ) There were a total of 8 state personality measures which correlated significantly with the various sleep measures ( p = .05). About 20 significant correlations should have been found by chance alone. ( b ) An individual examination of each sleep measure showed that no sleep measure was correlated ( p = .05) with more than one state personality measure. At least one signifi'We gratefully acknowledge the support of NASA Grant N G R 10-005-057. 'The matrices are on file in Document NAPS-02777. Order from Microfiche Publications, 440 Park Avenue South, New York. N.Y. 10016. Remit $3.00 for microfiche or $6.00 for photocopy.
1182
W . B. WEBB, ET AL.
cant correlation would be expected by chance. ( c ) Only one correlation was significant ( p = . 0 1 ) . The amount of alpha produced prior to sleep onset correlated -.47 with the rating of "concentration at bed time." Four significant correlations would have been expected by chance. ( d ) N o trait variable was correlated significantly with any sleep event
( 9 = .05). Our conclusions are, of course, limited by the validity and range of out measures. W e recognize that the tests were not perfect and all aspects of personality were not assessed. However. they were the best we could find and were as broad ranging as possible. Sleep stages were measured as fully as possible. Also, since the completion o f our study, a srudy ( 4 ) relating various sleep measures to rhe Freiburg Personality Inventory has come to our attention. This inventory gives scores on 12 different personality traits including drpression, extraversion and several traits not measured in the present srudy. A casual glance at the correlation matrix of Schubert and Jovanovic indicates fewer correlations than would be expected by chance with no compelling pattern evident in the significant correlations. These results corroborate our trait personality findings with different measures and strengthen our conclusion that in normal healthy young adults individual differences in state or trait variables are not strong determinants of characteristics of sleep stage. W e must add a cautionary statement. W e are not saying that personality disturbances or extreme mood states have no effect on sleep. Anxieties, depressions, indeed elationsin either trait o r srate dimensions-can and do intrude on the sleep process. Any variable, whether internally or externally generated, that serves as a source of continuing engagement with the waking world ho!ds a potential threat for sweet sleep. W e are saying that our data indicate that, short of sharp deviations, our sleep stages are little determined by our personal states and traits. REFERENCES 1. AGNEW,H. W., JR.,6: WEBB,W. B. Sleep srage scoring. ]ournu/ Abstract Supplement of American Psychological Association, 1972, Manuscript No. 293. 2. CROWNE.D. P., & MARLOWE, D. A new scale of social desirability indcpendenr of psychopathology. Journal o f Conrrrlting Psychology, 1960, 24, 349-354. 3. NOWLIS,V. Research with rhe Mood Adjective Check List. I n S. S. Tomkins & C. E. Izard (Eds.), Affecs, cognijion, and personality. New York: Springer, 1965. Pp. 352-389. 4. SCHUBERT,F. C., & JOVANOVIC.U. J. Sleep behavior--especially falling asleep and awakenings during the night-in adults in relation to personality variables. In U. Jovanovic ( E d . ) , The nature o f d e e p . Stuttgart: Fischer, 1973. Pp. 123-126. C. D., GORSUCH,R. L., & LUSHENE,R. E. STAl manrial for the State5. SPIELBERCER, Tfait Anxiety Inventory. Palo Alto: Consulting Psychologists Press, 1970. 6. WIGGINS,J. S. Substantive dimensions of self-report in the MMPI item pool. Psychological Monographs, 1966, 80, No. 22 ( W h o l e No. 6 3 0 ) . 7. ZUCKERMAN,M., & LINK, K. Construct validity for the sensation-seeking scale. lourndl of Consulting and Clinical Psychology, 1968, 32, 420-426.
Accepted April 13, 1976.
