Periodicities in Archived Card-Guessing Data: Preliminary Report on a Large Database

• Published in: The Journal of parapsychology 2000-09, Vol.64 (3), p.240-241
• Main Authors: Broughton, Richard S, Spottiswoode, S James P
• Format: Article
• Language: English
• Subjects: Experiments; Human performance; Laboratories
• ISSN: 0022-3387

Previous investigations by Spottiswoode have shown that (a) anomalous cognition or ESP is gready enhanced during a narrow window of local sidereal time (LST), an astronomical measure that indicates which slice of heavens is overhead at that time, and (b) an expected negative correlation between ESP and geomagnetic fluctuation (the ap index) is significantly strengthened during that same window of LST time. Less dramatic effects in the data indicate possible additional periodicities, such as a reduction of scoring during other LST periods. These findings suggest that there may be physical moderators of ESP performance of unknown but possibly celestial or solar/geomagnetic origin. These findings were based on a database of nearly 3,000 trials of free-response data from remote viewing and ganzfeld experiments. To follow up on these findings the authors drew on the archives of the Duke University Parapsychology Laboratory to compile a database of good-quality, relatively standard ESP experiments that exhibited strong overall evidence of ESP. Sixteen data sets from recognized card-guessing experiments of the 1930s contributed a total of 7,167 runs, mostly from two laboratories. The combined z score for these data is 18.79. Effect sizes were calculated and plotted in LST space using a sliding 2-hr window as in the previous investigations. Similarly, Spearman's rank correlation was calculated in a 2-hr sliding window and plotted in LST space. The effect size (ESP scoring) data revealed two periods of significantly enhanced scoring and 2 periods of depressed scoring that were similar, but not exactly the same as those found in the free-response data. The correlation with ap was rs= .036, p - .002, two-tailed. This positive correlation is contrary to the expected weak negative correlation found in other ESP data; however, the plot in LST space revealed that the correlation turns negative opposite the main peaks of ESP scoring, similar to what Spottiswoode observed earlier. These findings do not confirm Spottiswoode's specific finding of a high-scoring window centered on LST 13.5±1h, but they do suggest the presence of an LST-related influence on ESP performance that needs further elucidation. Several additional analyses made possible by the large database explored more common periodicities, such as the month, day of the week, and hour of the day in which the tests were conducted. May and September stood out as the best months for ESP testing, whereas January and Fe