Cleve Backster

Cleve Backster (1924–2013) was an American polygraph (lie-detector) examiner who, in 1966, attached galvanic-skin-response electrodes to a houseplant and reported that the plant’s readings reacted to his intentions — most famously claiming a plant registered “fear” when he merely thought about burning a leaf.

He generalized this into the theory of “primary perception,” the idea that plants, bacteria, and even cells in a test tube are sentient and respond to human thoughts and emotions, connected through some nonlocal channel.

His claims were popularized by the 1973 bestseller The Secret Life of Plants. His experiments were not properly controlled, and when scientists attempted careful replication (notably Horowitz, Lewis, and Gasteiger in 1975, published in Science), they found no evidence of the claimed plant responses; the original readings were attributable to electrode artifacts, static, and uncontrolled environmental variation.

No mainstream evidence supports plant “primary perception” of human thought. Yet Backster remains a fixture of manifestation and “consciousness affects matter” literature, cited as proof that intention is detected by the living world. He is a clear example of the gap between a colorful anecdote and replicable.