At the 2005 Meeting of the Society for Scientific Exploration in Gainesville, Florida, Dr. Edgar Mitchell, the 6th man to land on the moon and co-founder of the Petaluma, California-based Institute of Noetic Sciences (IONS) mentioned the psi blocker effect. He described noticing that the famous "psychic" Uri Geller would have a difficult time demonstrating his abilities when certain individuals were in the laboratory at Stanford Research Institute at Stanford University. When the individuals in question were sent off to get coffee or the like, this blocking effect was lifted.
Could those who are convinced psi phenomena are impossible and that they are not even worthy of study use their own consciousness to affect experiments without even realizing it? Or is this a convenient excuse for psi phenomena proponents to explain some experiments that fail to produce sufficiently convincing data or physical effects? If this is the case, when the closed-minded are involved in replicating experiments performed by open-minded ones, their results will simply meet their expectations. Might their data conform "too much" to this expectation to the point that it represents a statistical anomaly?
We leave you with some studies (1, 2) that speak to these matters. In a meta-analysis of research on distant mental influence on living systems (DMILS), we find reference to a study performed by a scientist open to the psi phenomena (Schlitz) and then repeated with the same conditions and protocol by a psi scoffer (Wiseman). Schlitz's data set represented a p-score of 0.02, whereas Wiseman's translated to a p-score of 0.32. The difference in the statistical significance is tremendous. One says that there is a 2 in 100 chance that the effects are due to chance, where as the other indicates a nearly 1/3 chance that the effects are due to chance. In the 2006 SSE Meeting, another paper, made reference to this effect: "Kevin Walsh, Effect of Subject Bias on Psi: Self-Fulfilling Prophecies." The psi blocker effect could lead scientists to rule out a real phenomenon as unlikely (this is referred to as a Type II Error). Note that neither experimental result "proves" or "disproves" DMILS. Science does not prove. It refutes, but still has a margin for error.
At the same conference subtle energy researcher William Bengston presented "Placebo Effect, Type II Errors, and Resonance: Some Implications from Healing Research for Experimental Methods." Here, Dr Bengston related a case whereby the control groups of sick mice that were not treated with exteriorizations of bioenergy (vital energy, chi) were similarly healed as sick mice that received chi treatment. One could dismiss the effect by seeing that there was no significant difference in outcome between the experimental and control groups. However, both performed better than when there was no treatment at all.