Resolving the relationships between placebos, misattribution, and insomnia: an individual-differences perspective

In Storms and Nisbett's (1970) original study of therapeutic misattributions, insomniacs given a placebo "arousal" pill went to sleep faster, whereas insomniacs given a placebo "relaxer" pill took longer than usual to fall asleep. This reverse placebo effect has been difficult to replicate; indeed, in several instances significant placebo effects have been obtained. In the present study we reasoned that insomniacs who are more attentive to internal bodily processes would be more apt to yield a reverse placebo effect, whereas those attentive to external stimuli would be more likely to be directly influenced by the suggested effects of the placebo. Thirty insomniacs completed trait measures of private body consciousness, private self-consciousness, and self-esteem. The procedure of Storms and Nisbett was then replicated. As predicted, subjects with high private body consciousness exhibited a stronger reverse placebo effect than did those subjects low on this dimension. Subsequent analyses revealed that this effect was entirely attributable to the low- rather than to the high-self-esteem participants. The effect of private self-consciousness was nonsignificant in all analyses. Theoretical implications are discussed.