Journal of Consulting and Clinical Psychology 1979, Vol. 47, No. 1, 213-215 Self-Deception, Other-Deception, and Self-Reported Psychopathology Harold A. Sackeim Columbia University Ruben C. Gur University of Pennsylvania Inventories designed to assess self-reported psychopathology, other-deception (lying), and self-deception were administered to a group of 250 subjects. Substantial negative correlations were found between self-deception and psy- chopathology scores, and the relationships between the self-deception and psychopathology scores were stronger than those between the other-deception and psychopathology measures. The findings support the view that self-decep- tion significantly contributes to the invalidity of self-report inventories and more so than does other-deception. The possibility is raised that self-deception is a moderating variable contributing to the lack of agreement between clin- ical and actuarial forms of assessment. Considerable theoretical and experimental at- tention has been devoted to examining the influ- ence of other-deception, or lying, on personality measurement. Despite the fact that the signif- icance of self-deception in producing non-con- tent-based responding on self-report personality inventories has been emphasized (e.g., Anastasi, 1961), the relationship of self-deception to per- sonality measurement has not been systemati- cally investigated. Indeed, Meehl and Hathaway (1946) in discussing the limitations of lie scales claimed, "What is much more important, they [lie scales] are mainly directed at the sort of conscious falsehood which most writers have stressed, while ignoring the more subtle tend- encies to self-deception which are probably of even greater importance in affecting scores" (p. 528). The lack of empirical research con- cerning the influence of self-deception on as- sessment may be attributable to the absence until recently of a criterion-validated measure of self-deception. 1 Sackeim and Gur (1978) have demonstrated that a specific phenomenon, that is, misiden- tifications of audiotape voices of self and others, fulfills the criteria that are necessary and suf- ficient for ascribing self-deception. In establish- ing that these errors are instances of self- deception, they showed that while making- such Requests for reprints should be sent to Harold A. Sackeim, Department of Psychology, Schermer- horn Hall, Columbia University, New York, New York 10027. misidentifications, subjects simultaneously make correct identifications at processing levels out- side of awareness, that subjects are not aware of committing errors, and that the commission of errors is under motivational control. They also constructed a questionnaire intended to assess individual differences in tendencies to engage in self-deceptive behavior. The Self- Deccption Questionnaire (SDQ) consists of 20 items, the positive endorsements of which were judged to be universally true but psycho- logically threatening, for example, ''Have you ever enjoyed your bowel movements?" and "Have you ever made a fool of yourself?" Items are rated on 1 to 7 Likert-type scales for fre- quency or intensity of the behavior in question, and ratings of 1 or 2 on items are scored as instances of self-deception. In a sample of 55 undergraduates, the SDQ had a test-retest reliability of .81 with 4- to 10-week intervals between administrations. Subjects who dis- played self-deceptive behavior by committing errors in identifying voices of self or others scored higher on this measure than subjects who did not commit errors. The purpose of the present study was to examine the relationships 1 It should be noted that the K (Test-Taking Attitude) scale of the MMPI was originally offered as a general measure of clefensiveness (Meehl & Hathaway, 1946). However, particularly in regard to normal populations, there is considerable evi- dence that high K scores do not reflect defensive- ness or self-deceptive behavior but rather psycho- logical health (e.g., Heilbrun, 1963). Copyright 1979 by the American Psychological Association, Inc. 0022-006X/79/4701-0213$00.75 213