What about plants?

By Daniel K. Wilson

There are some people, in an attempt to discredit vegetarians and vegans, who argue that plants have feelings too and it’s just as cruel to eat them as it is to eat animals. Of course, these people don’t abstain from eating plants themselves; quite the opposite. They raise the issue to justify eating animals. In other words, it doesn’t matter what you eat because something had to die, so why worry about any of it?

It may sound ridiculous (or like something from a sci-fi movie) to say that plants are intelligent and cringe at the thought of being eaten but it’s worth remembering that not so long ago people scoffed at the idea of animal sentience, likening the screams of tortured dogs to a clock striking twelve. And while I’ve never heard of anyone protesting the mistreatment and slaughter of carrots (vegetable rights activists?), I’d still like to give them the benefit of a doubt.

The idea of plant sentience was first recorded in 1848 by Dr. Gustav Fechner, who believed plants were capable of emotions just like humans and animals, and would grow big and strong if only they were spoken to with love and affection. Even early Buddhists and some present-day Jains consider plants to be at least borderline beings, meaning they are partly sentient, and apply the principle of ahimsa, or non-violence, to them.

Perhaps the most famous advocate of plant sentience is Cleve Backster, a polygraph expert and founder of the FBI’s polygraph unit. In 1966, Backster decided to hook up a lie detector to his Dracaena Massangeana and measure the electrical impulses of the leaves. He thought to himself, “I am going to burn that plant leaf, that very leaf that's attached to the polygraph,” and immediately the machine “went into a wild agitation.” Backster was convinced that the plant was reading his mind and reacting to his intent to burn it.

His partner at the polygraph school was able to get the same results, so long as he intended to burn the plant leaf. If his partner only pretended to intend to burn the leaf, it wouldn't react, leading Backster to the conclusion that the plant could distinguish between real intentions and made-up ones.

Backster’s findings were published in the International Journal of Parapsychology in 1968 and he wrote a book on the subject called Primary Perception. He also believes the bacteria in yogurt are conscious and that plants can communicate with humans and other life forms.

Supporters claim that his experiments have been reproduced thousands of times with exactly the same results, thus “proving” that plants are sentient. Backster’s work was also the inspiration for the best-selling book, The Secret Life of Plants, which promotes the idea that plants are telepathic and experience emotions such as fear and love.

But Backster’s experiments were heavily criticized by the scientific community because he had not used proper controls during his research. When a group of scientists in the late 70’s conducted their own tests under controlled laboratory conditions, the plants did not react to thoughts or threats of violence and it was concluded that the readings Backster had recorded could have been the result of a number of factors including static electricity, movement in the room, changes in humidity, etc.

More recently, the idea of primary perception was put to the test on an episode of Mythbusters (to prove if plants are telepathic). A polygraph machine was connected to a number of plants, and then the “busters” inflicted both physical and imaginary harm to the plants, and other plants nearby. The polygraph recorded some kind of reaction, but it wasn’t consistent, occurring only about a third of the time. The researchers concluded that “if it’s not repeatable, it’s not science,” and plants are NOT telepathic.

As far as we know, all living beings need to have a brain to experience emotions and a central nervous system to feel pain. Plants have neither. A plant can react and respond to stimuli, such as light, gravity and touch, but whether they feel pain, are conscious and have interests is doubtful.

Some believers however, argue that just because plants don’t have brains, they may still be sentient, and note that animals need hearts to live but plants do not. They say that plants may be alive through different principles that we currently don’t know about and therefore could have senses that don’t rely on the same systems that animals do, including a brain. Plants may be conscious through different principles as well.

But if plants are sentient, their existence would be the cruelest joke of nature or God; beings capable of suffering yet possessing no means whatsoever of escaping that suffering. Animals have adapted to feel pain and fear to avoid dangerous situations, something plants are unable to do. It simply wouldn’t benefit plants to possess these characteristics.

So is it possible that plants are sentient? Sure, anything’s possible. Is it likely? No, I don’t believe it is. But if it turns out that vegetables are sentient, I guess I will have to become a fruitarian (someone who eats only raw fruits and seeds). I went vegan when I found out that animals, even dairy cows and egg-laying chickens, suffer and die simply because we like the taste of their flesh. If vegetables also suffer, then as a pacifist, I would have to stop eating them as well. Right now, there’s no convincing evidence that they do.