Carlos S. Alvarado, PhD, Research Fellow, Parapsychology Foundation

Several meta-analyses have beeen published about parapsychological experiments in recent years (click here and here). If you want to get a short overview of this see Lance Storm’s recent introductory online article on the topic (Meta-analysis in parapsychology. In R. McLuhan (Ed.), Psi Encyclopedia. London: Society for Psychical Research). The article opens explaining the topic:

“Meta-analysis is a statistical procedure that combines the results of a number of studies in a particular area of research in order to provide a more robust finding. The method has been embraced by parapsychologists since the 1980s, since the results of meta-analyses tend overwhelmingly to confirm the statistically significant findings of individual psi studies, underscoring the existence of psi as a genuine phenomenon. However, this apparent success has contributed to doubts about the value of meta-analysis among those who question the reality of psi, fueling controversy about its true worth.”

Lance Storm 2

Lance Storm

Summaries of several meta-analyses about ESP and psychokinesis experiments are presented. This includes ganzfeld, dream, presentiment, and dice throwing studies. Storm presents the results of meta-analyses that both support and do not support the existence of psi effects. He cautions readers that not all areas of research have been meta-analyzed, “these domains (perhaps up-and-coming in some cases) may as yet be represented by too few studies to warrant meta-analysis, or they have been subsumed by other domains (for instance, RV [remote viewing] in free-response), or they do not lend themselves to meta-analytic treatment . . . For most domains, experimentation continues, with experimental designs becoming increasingly sophisticated and innovative.”

Some studies cited by Storm:

Bem, D. J., Palmer, J., & Broughton, R. S. (2001). Updating the ganzfeld database: A victim of its own success? Journal of Parapsychology, 65, 207-218.

Bösch, H., Steinkamp, F., & Boller, E. (2006). Examining psychokinesis: The interaction of human intention with random number generators. Psychological Bulletin, 132, 497-523. Abstract

Honorton, C., & Ferrari, D. C. (1989). “Future telling”: A meta-analysis of forced-choice precognition experiments, 1935-1987. Journal of Parapsychology. 53, 281-308.

Milton, J. (1997). Meta-analysis of free-response ESP studies without altered states of consciousness. Journal of Parapsychology, 61, 279-319.

Milton, J., & Wiseman, R. (1999). Does psi exist? Lack of replication of an anomalous process of information transfer. Psychological Bulletin, 125, 387-391.

Mossbridge, J., Tressoldi, P. & Utts, J. (2012). Predictive physiological anticipation preceding seemingly unpredictable stimuli: a meta-analysis. Frontiers in Psychology, 3, 1-18. doi: 10.3389/fpsyg.2012.00390

Radin, D. I., & Nelson, R. D. (1989). Evidence for consciousness-related anomalies in random physical systems. Foundations of Physics, 19, 1499-1514.

Radin, D. I., & Ferrari, D. C. (1991). Effects of consciousness on the fall of dice: A meta-analysis. Journal of Scientific Exploration, 5, 61-83.

Schmidt, S., Schneider, R., Utts, J., & Wallach, H. (2004). Distant intentionality and the feeling of being stared at: The meta-analyses. British Journal of Psychology, 95, 235-247. Abstract

Sherwood, S. J., & Roe, C. A. (2003). A review of dream ESP studies conducted since the Maimonides dream ESP studies. In J. Alcock, J. Burns, & A. Freeman (Eds.), Psi wars: Getting to grips with the paranormal (pp. 85-109). Thorverton, UK: Imprint Academic.

Sherwood, S. J., & Roe, C. A. (2013). An updated review of dream ESP studies conducted since the Maimonides dream ESP program. In S. Krippner, A. J. Rock, J. Beischel, & H. Friedman (Eds.), Advances in parapsychological research 9 (pp. 38-81). Jefferson, NC: McFarland. Abstract

Stanford, R. G., & Stein, A. G. (1994). A meta-analysis of ESP studies contrasting hypnosis and a comparison condition. Journal of Parapsychology, 58, 235-269. Abstract

Steinkamp, F., Milton, J., & Morris, R. L. (1998). A meta-analysis of forced-choice experiments comparing clairvoyance and precognition. Journal of Parapsychology, 62, 193-218.

Storm, L., Tressoldi, P. E., & Di Risio, L. (2010b). Meta-analyses of free-response studies 1992-2008: Assessing the noise reduction model in parapsychology. Psychological Bulletin, 136, 471-485. doi:10.1037/a0019457.

Storm, L., Tressoldi, P. E., & Di Risio, L. (2012). Meta-analyses of ESP studies 1987-2008: Assessing the success of the forced-choice design in parapsychology. Journal of Parapsychology, 76, 243-273.