An experiment tested whether mental coherence entrained in groups would affect sequences of data generated by truly random number generators (RNGs) in the vicinity of those groups. Coherence was entrained by having groups listen to a prescribed series of binaural beat rhythms during a 6-day workshop. Two RNGs based on electronic noise and one on radioactive decay latencies were located in the building where the workshops took place. Random data were continually collected from these RNGs during 14 workshops. As controls, (...) the same RNGs generated data in the same locations and times but during 8 weeks when no workshops took place. Other RNGs in two distant locations were run as additional controls. An exploratory hypothesis predicted that fl uctuations in entrained mental coherence associated with the workshop activities would modulate the random data recorded during the workshops. This was predicted to result in positive correlations between random data streams collected from one workshop to the next. Results showed that during the workshops the overall correlation was positive, as predicted (p =.008); during control periods the same RNGs produced chance results (p =.74). Random data generated in distant locations also produced results consistent with chance. (shrink)