Defining hypnosis as a trance vs. cooperation: Hypnotic inductions, suggestibility, and performance standards

We compared participants' responsiveness to a standard administration of a hypnotic suggestibility scale (CURSS; Spanos, Radtke, Hodgins, Bertrand, Stam, & Moretti, 1983) that defined the ability to experience hypnosis in terms of cooperation (SI; standard induction, N = 27) with a version of the same scale administered with all references to cooperation removed (CR; cooperation removed, N = 34) and with a version of the scale with the "induction" removed (NI; no induction, N = 35). In a fourth condition, participants were informed that the ability to experience hypnosis depended on their ability to achieve an altered state of consciousness or "trance" (AS; altered state, N = 33). Removing instructions for cooperation had an effect on objective (CR < SI) but not on subjective hypnotic responding. Removing the hypnotic induction had no appreciable effect on any dimension of hypnotic responsivity. Consistent with predictions derived from performance standards theory (Lynn & Rhue, 1991), participants who received the altered state set responded to fewer suggestions than did participants who received the standard induction (SI). Estimates of suggestions passed that were assessed before and after test suggestions were administered were, respectively, weakly to moderately correlated with objective and subjective measures of hypnotic suggestibility.