Spanos and Hewitt (1980) have recently argued, on the basis of an experiment they report, that Hilgard's "hidden observer" phenomenon is pure laboratory artifact. This report reviews their claim and concludes on the following grounds that their experiment does not warrant so sweeping a conclusion: (a) Spanos and Hewitt have posed the issue as fact versus fiction and do not appear to be aware of a third alternative, namely, that the hidden observer effect is a phenomenon encountered in hypnosis that may be influenced both by demand characteristics and by the social-psychological context. (b) They appear to obtain the effect 100% of the time, unlike Hilgard, who has emphasized the phenomenon's differential incidence. (c) In contrast to Hilgard, who furnishes abundant verbal reports of his subjects' phenomenal experience as buttressing evidence for the "genuineness" of the effect in subjects who report having it, Spanos and Hewitt do not. (d) Two major procedural aspects of their experiment are discussed. Either or both may have inadvertently influenced the outcome of their experiment in the direction of their hypothesis that the responses of subjects are entirely the product of experimenter-induced expectations.

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