BIAS. “McConnell’s results are now attributed to observer bias. No blinded experiment has ever reproduced his results of ‘maze-running’. Subsequent explanations of maze-running enhancements associated with cannibalism of trained planarian worms were that the untrained flatworms were only following tracks left on the dirty glassware rather than absorbing the memory of their fodder.”
https://en.m.wikipedia.org/wiki/Planarian