Princeton Engineering Anomalies Research

Robert G. Jahn was an aerospace engineer and Princeton's dean of the School of Engineering and Applied Science when, in 1979, a student's interest in psychokinesis experiments led him to open a small laboratory to test whether human intention could influence the statistical output of electronic random event generators, machines producing streams of random binary digits from electronic noise.

Jahn justified the project to a skeptical administration as a legitimate engineering anomalies question, arguing that if operators could reliably bias supposedly random hardware even slightly, the effect would matter for any system that depended on true randomness, a framing that let him house the lab within engineering rather than psychology. He recruited Brenda Dunne, a developmental psychologist trained at the University of Chicago, as laboratory manager, and the two directed PEAR together for its entire existence with a small permanent staff supplemented by students and visiting researchers. The lab's core protocol asked volunteer operators to try to mentally influence a random event generator's output toward a pre-specified direction across very large numbers of trials, on the reasoning that even a tiny, consistent statistical deviation from chance, if genuine, would accumulate into a detectable signal only across millions of trials rather than a handful of dramatic ones.

PEAR's published results, which claimed small but statistically significant operator effects accumulated across decades of trials, drew sustained criticism almost from the start. In 1988 a committee of the U.S. National Research Council reviewing parapsychological research examined PEAR's random event generator experiments, and the psychologist James Alcock's critical analysis for that review identified serious methodological problems, including weak controls, incomplete documentation, and results driven disproportionately by a small number of individual operators rather than a consistent effect across participants.

A large multi laboratory replication effort around 2000, conducted jointly by PEAR and two German research groups at Giessen and Freiburg using PEAR's own software and hardware under a shared protocol, produced positive but statistically non-significant trends at all three sites, a result widely read outside the lab as failing to confirm the effect under independent conditions. Princeton's administration, which had tolerated PEAR for nearly three decades as Jahn's personal project rather than a funded, peer reviewed research program, allowed it to close when Jahn retired in February 2007; a university spokesperson at the time noted that PEAR's research had fallen well outside the mainstream and had rarely been published in rigorously peer reviewed physics or psychology journals. Jahn and Dunne continued related work afterward through the International Consciousness Research Laboratories, a network of independent researchers, while PEAR itself ceased operating as a Princeton facility.