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Excerpt from The Myth of Human Supremacy

Can Plants Learn? (p. 86)

From chapter "Complexity and Its Opposite"

The Enlightenment and the Scientific Revolution are based on seeing the world as a giant machine, and nonhumans as “beast machines,” as Descartes put it. Modern scientific discourse is, as would be expected considering the basis of modern science, based on machine language. But machines are a uniquely human-made project. You can’t get more anthropomorphic than to describe the world in mechanistic terms, to project a human construct onto the real, living world. This is one reason I do not speak, for example, of ecosystems, but rather natural communities.

Their use of the word anthropomorphizing is even more ironic and absurd than I’ve so far made it seem: isn’t it just a tad anthropomorphic to require that everyone else’s intelligence, response to pain, sorrow, joy, and so on, resemble one’s own?

Or maybe it’s just narcissistic.

Michael Pollan asked plant neurobiologist Stefano Mancuso “why he thinks people have an easier time granting intelligence to computers than to plants. ([Prominent botanist] Fred Sack told me [Pollan] that he can abide the term ‘artificial intelligence,’ because the intelligence in this case is modified by the word ‘artificial,’ but not ‘plant intelligence.’ He offered no argument, except to say, ‘I’m in the majority in saying it’s a little weird.’) Mancuso thinks we’re willing to accept artificial intelligence because computers are our creations, and so reflect our own intelligence back at us. They are also our dependents, unlike plants: ‘If we were to vanish tomorrow, the plants would be fine, but if the plants vanished . . .’ Our dependence on plants breeds a contempt for them, Mancuso believes. In his somewhat topsy-turvy [sic] view, plants ‘remind us of our weakness.’”

Mancuso’s point is a good one, to which we will return.

The evolutionary ecologist Monica Gagliano wanted to determine whether plants are capable of learning. Given that industrial humans have destroyed or are destroying every natural community they try to manage (read, steal from and try to control), yet they still continue to try to manage (steal from and try to control) every natural community they can find instead of leaving them alone; and given that industrial civilization is killing the planet, and yet most industrial humans don’t seem interested in even acknowledging that industrial civilization is killing the planet, much less getting rid of it, and thereby allowing life on this planet to continue, I’d be more interested in determining whether industrial humans are capable of learning. Be that as it may, she came up with a fascinating way to conduct her experiment.

Pollan writes, “She focused on an elementary type of learning called ‘habituation,’ in which an experimental subject is taught to ignore an irrelevant stimulus. ‘Habituation enables an organism to focus on the important information, while filtering out the rubbish,’ Gagliano explained to the audience of plant scientists. How long does it take the animal to recognize that a stimulus is ‘rubbish,’ and then how long will it remember what it has learned? Gagliano’s experimental question was bracing: Could the same thing be done with a plant?

Mimosa pudica, also called the ‘sensitive plant,’ is that rare plant species with a behavior [and I love the fact that he used the word behavior] so speedy and visible that animals can observe it; the Venus flytrap is another. When the fernlike leaves of the mimosa are touched, they instantly fold up, presumably to frighten insects. The mimosa also collapses its leaves when the plant is dropped or jostled. Gagliano potted fifty-six mimosa plants and rigged a system to drop them from a height of fifteen centimetres every five seconds. Each ‘training session’ involved sixty drops. She reported that some of the mimosas started to reopen their leaves after just four, five, or six drops, as if they had concluded that the stimulus could be safely ignored. ‘By the end, they were completely open,’ Gagliano said to the audience. ‘They couldn’t care less anymore.’

“Was it just fatigue? Apparently not: when the plants were shaken, they again closed up. ‘“Oh, this is something new,”’ Gagliano said, imagining these events from the plants’ point of view. ‘You see, you want to be attuned to something new coming in. Then we went back to the drops, and they didn’t respond.’ Gagliano reported that she retested her plants after a week and found that they continued to disregard the drop stimulus, indicating that they ‘remembered’ [and I see no need for scare quotes] what they had learned. Even after twenty-eight days, the lesson had not been forgotten. She reminded her colleagues that, in similar experiments with bees, the insects forgot what they had learned after just forty-eight hours. Gagliano concluded by suggesting that ‘brains and neurons are a sophisticated solution but not a necessary requirement for learning,’ and that there is ‘some unifying mechanism across living systems that can process information and learn.’”

As Cleve Backster said, “It seems impossible, given the sophistication of modern instrumentation, for us to keep missing this fundamental attunement of living things. Only for so long are we going to be able to pretend it’s the result of ‘loose wires.’ We cannot forever deny that which is so clearly there.”

He underestimated the power of denial. By now we can predict the response of the supremacists. One scientist’s reasoned response was “Bullshit.” And the tautologies. Oh, the tautologies. Only animals can learn because, well, only animals can learn. Plants can “evolve adaptations” but never learn. Never mind that we don’t normally talk about beings evolving adaptations within a single generation, unless you want to say that children, uh, evolve an adaptation into reading when parents read to them, in which case we’re back to learning, only using fancier words. Further, as Gagliano said, “How can they be adapted to something they have never experienced in their real world?” She noted that some plants learned faster than others, evidence that “this is not an innate or programmed response.” Another scientist said that there’s nothing to discuss, because no matter what happened, “it’s not learning.” And why is it not? Evidently because, well, it just isn’t. So there.

The relevant question is whether these scientists are capable of learning. Perhaps we can devise an experiment where we drop them from a height of fifteen centimeters every five seconds until they change their behavior.

Pollan continues, “Someone objected that dropping a plant was not a relevant trigger, since that doesn’t happen in nature. Gagliano pointed out that electric shock, an equally artificial trigger, is often used in animal-learning experiments. Another scientist suggested that perhaps her plants were not habituated, just tuckered out. She argued that twenty-eight days would be plenty of time to rebuild their energy reserves.”

Gagliano has been trying to get the article published, but so far ten journals have rejected it. Pollan quotes her saying, “‘None of the reviewers had problems with the data.’ Instead, they balked at the language she used to describe the data. But she didn’t want to change it. ‘Unless we use the same language to describe the same behavior’—exhibited by plants and animals—‘we can’t compare it,’ she said.”

This makes me happy.