Precognitive dreaming: Investigating anomalous cognition and psychological factors

Surveys of the general population show that reports of psi-related experiences such as apparent clairvoyance, telepathy, and precognition are common throughout the world. For example, a 1987 survey published by the University of Chicago's National Opinion Research Center canvassed nearly 1,500 adult Americans, of whom 67% claimed psi-related experiences (Greeley, 1987). Precognition--seemingly knowing about an event that has yet to take place--was reported by approximately one third of respondents in a recent survey of 1,000 Britons (Pechey & Halligan, 2012). Dreams seem to play a particularly important role in precognitive experiences. A review of the various surveys of spontaneous GESP experiences concludes that, if only precognitive cases are considered, around 60% involve dreams, with a further 10% involving "borderland" states (Van de Castle, 1977). Therefore, the vast majority of spontaneous precognitive experiences involve dreams or sleep-related states. Death is a predominant theme in precognitive dreams, followed by accident and injury; percipients are predominantly female (e.g., Green, 1960; Saltmarsh, 1934), although reporting bias may account for both of these trends. When considering possible explanations for spontaneous paranormal experiences, researchers often either consider a paranormal interpretation, or one of several possible psychological explanations, although these are not mutually exclusive categories. Researchers tend to turn to controlled laboratory settings to test the psi hypothesis. Only a minority of laboratory dream ESP studies have investigated precognition, which is perhaps odd given the prevalence with which spontaneous dream precognition experiences are reported. Controlled laboratory studies of dream ESP took off from 1962, after psychiatrist Montague Ullman established a dream laboratory at the Maimonides Medical Center in Brooklyn, New York (Krippner, 1993; Ullman et al., 1973, 1989). Thirteen formal dream ESP studies (11 telepathy, 2 precognition) were conducted at the lab before it closed in 1978, the majority of which obtained medium to large positive effect sizes (Sherwood & Roe, 2003). A review of the 21 post-Maimonides dream ESP studies identified that, for the majority of them, the research environment had moved from the relatively expensive and time-consuming sleep laboratory to participants' own homes (Sherwood & Roe, 2003). The studies had a modest combined effect size (r = .14)--significantly less than for the Maimonides studies, but still regarded as "successful" by Sherwood and Roe, who expressed the hope that dream ESP research would be "re-awakened. " Turning to possible psychological factors underlying paranormal experiences, Blackmore and Moore (1994) proposed that paranormal believers and disbelievers might have different cognitive styles. They tested this idea by presenting participants with ambiguous pictures and found that believers guessed the identity of the picture earlier than disbelievers, though the believers were more often incorrect in these guesses. In this study, therefore, believers tended to rapidly evaluate the ambiguous stimuli and, compared to disbelievers, set a lower criterion for identifying these patterns. This propensity seems related to intolerance of ambiguity, which is conceptualised as a form of premature closure achieved through a tendency to resort to clear-cut solutions in ambiguous situations (Frenkel-Brunswick, 1949). Houran and Williams (1998) explored the relation between ambiguity tolerance and specific paranormal experiences using Kumar, Pekala, and Gallagher's (1994) Anomalous Experiences Inventory and MacDonald's (1970) Ambiguity Tolerance scale. They reported that there was a small but positive correlation between experiences involving internal or physiological experiences, such as precognitive dreams, visual apparitions, and out-of-body experiences, and tolerance for ambiguity. This finding seems to be inconsistent with Blackmore and Moore's (1994) conclusion, leading Houran and Williams (1998) to suggest that variability in the measures used across different studies may contribute to the equivocal association between ambiguity tolerance and paranormal beliefs and experiences. …