(Investigator 112, 2023 September)

What would the world be like without plants, flowers and trees? The answer is simple, we wouldn’t be around to find out. The importance of plant life to man’s survival tends to be overlooked by many and taken for granted by others. They take in carbon dioxide and expel the oxygen necessary for us to breath, they synthesize food out of air, soil and sunlight to feed man and beast, provide us with a variety of drugs, intoxicants and medicines, and directly and indirectly supply us with all that is necessary to sustain life, health and shelter.

Despite their value and because of their slower pace than humans, we tend to regard them as relatively inanimate, devoid of sensations, emotions or sense. To associate psychic intelligence with plants would in the normal course of events invite ridicule, but before we look at that aspect and one of its principal proponents, Cleve Backster, let’s take a brief look at some of the miracles plants are capable of in their everyday life.

The great nineteenth century botanist Charles Darwin proved that every one of a plant's multitudinous tendrils had the power of independent movement seeking out that which is to their advantage. There are carnivorous plants that trap and consume insects, shrubs that live in salt water changing it through osmosis to fresh water, flowers that grow petals to imitate the female of a species of fly to entice it to pollinate, and so on through a fascinating and almost unbelievable variety of ingenious accomplishments. So it seems logical to raise the question, are plants guided by some innate intelligence?

Cleve Backster, a polygraph (lie-detector) examiner seemed to think so. A basic component of the polygraph is a galvanometer, an instrument used to measure the human body’s electrical potential. As this potential fluctuates under the stimulus of thought and emotion, carefully structured questions have been used by police to question suspects and by monitoring the fluctuations on a graph were able to identify deception. The most effective way to trigger a reaction in a human being is to threaten their well-being, this prompted Backster to initiate experiments to see whether the same reaction occurred in plants. In 1966, on impulse, he attached the electrodes of a lie detector to a leaf on a dracaena plant to see if there was any reaction when he poured water on its roots. To his surprise the galvanometer didn’t show less resistance as would have been expected, but instead, a sawtooth motion on the graph paper showing a reaction similar to that of a human being experiencing an emotional stimulus. He then conceived the idea of threatening the leaf by burning it, but before he could even light the match there was a dramatic change in the pattern on the graph. Could it be that the plant had somehow sensed danger? Further experiments convinced Backster that plants were not only capable of an affinity between them and its keeper, but had some sort of cellular consciousness and even a memory. The results of Backster’s experiments were published under the title "Evidence of Primary Perception in Plant Life" in the winter of 1968 in Volume X of The International Journal of Parapsychology.


One scientific safeguard against the promulgation of bogus findings, errors or fraud, is the replication of an experiment by independent researchers. In Backster's case all attempts by others to replicate Backster's experiments have produced negative results. Further, the results obtained with the use of an instrument such as a polygraph is totally unreliable.

Further reading

Horowitz, K.A. et al. 1975. "Plant Primary Perception: Electrical unresponsiveness to brine shrimp killing." Science. 189:478-480.

Johnson, R.V. 1972. "To the Editors." Journal of Parapsychology. 36:71-72.

Shneour, Elie A. 1990. "Lying About Polygraph Tests" Skeptical Inquirer. 14 (3):292-297

From: Edwards, H. 1994 Magic Minds Miraculous Moments, Harry Edwards Publications