Moving the Goalposts for Plant Intelligence

What Cleve Backster’s research into plant intelligence reveals about the attunement of living things.


| Summer 2016



Plant Intelligence

Cleve Backster could name the moment the focus of his life changed forever, from lie detection to plant intelligence: early in the morning on February 2, 1966, at 13 minutes, 55 seconds of chart time for a polygraph he was administering. He had threatened the subject’s well-being in hopes of triggering a response. The subject had responded electrochemically to this threat. The subject was a plant.

Photo by Miguel Perez/www.flickr.com/photos/116158297@N06/

Almost 20 years ago I interviewed Cleve Backster about plant intelli­gence. No, he wasn’t a botanist. He was one of the world’s experts on the use of polygraphs, or lie detectors. I know that sounds like an odd con­nection, but listen to his story, and the connection will become clear. Just after World War II he was a CIA interrogation specialist, and founded The Agency’s polygraph school. In 1960 he left the CIA and formed the Backster School of Lie Detection, to instruct police officers. This school is the longest running polygraph school in existence.

Backster could name the moment the focus of his life changed for­ever, from lie detection to plant intelligence: early in the morning on February 2, 1966, at 13 minutes, 55 seconds of chart time for a polygraph he was administering. He had threatened the subject’s well-being in hopes of triggering a response. The subject had responded electrochemically to this threat. The subject was a plant.

Here’s his story: “I wasn’t particularly into plants, but there was a going-out-of-business sale at a florist on the ground floor of the building, and the secretary bought a couple of plants for the office: a rubber plant, and this dracaena cane. I had done a saturation watering — putting them under the faucet until water ran out the bottom of the pots — and was curious to see how long it would take the moisture to get to the top. I was especially interested in the dracaena, because the water had to climb a long trunk, and then to the end of long leaves. I thought if I put the galvanic-skin-response detector of the polygraph at the end of a leaf, a drop in resistance would be recorded on the paper as the moisture arrived between the electrodes. … I noticed something on the chart resembling a human response on a polygraph: not at all what I would have expected from water entering a leaf. Lie detectors work on the principle that when people perceive a threat to their well-being, they physiologically respond in predictable ways. If you were conducting a polygraph as part of a murder investigation, you might ask a suspect, ‘Was it you who fired the shot fatal to so and so? If the true answer were yes, the suspect will fear getting caught lying, and electrodes on his or her skin will pick up the physiological response to that fear. So I began to think of ways to threaten the well-being of the plant. First I tried dipping a neighboring leaf in a cup of warm coffee. The plant, if anything, showed what I now recognize as boredom — the line on the chart just kept trending downward.

“Then at 13 minutes, 55 seconds chart time, the imagery entered my mind of burning the leaf. I didn’t verbalize; I didn’t touch the plant; I didn’t touch the equipment. Yet the plant went wild. The pen jumped right off the top of the chart. The only new thing the plant could have reacted to was the mental image.

“I went into the next office to get matches from my secretary’s desk, and lighting one, made a few feeble passes at a neighboring leaf. I real­ized, though, that I was already seeing such an extreme reaction that any increase wouldn’t be noticeable. So I tried a different approach: I removed the threat by returning the matches to the secretary’s desk. The plant calmed right back down.

“Immediately I understood something important was going on. I could think of no conventional scientific explanation. There was no one else in the lab suite, and I wasn’t doing anything that might have provided a mechanistic trigger. From that split second my consciousness hasn’t been the same. My whole life has been devoted to looking into this.”