Are plants intelligent? Science is beginning to think so

In 2013, The New Yorker published an article that set the plant sciences world on fire, forever changing the way both the public and researchers looked at and studied the plant kingdom. The article, introduced the world to the idea that plants may not be the benign organisms we all thought they were, but could exhibit intelligent behavior.

“The Intelligent Plant,” is a deep dive into the science of plant intelligence, postulating that despite an absence of a brain, plants are capable of certain levels of intelligent behavior that was previously unheard of. At the time, this was considered a hot take, bordering on outrageous. The plant biology community wasted no time proclaiming that the claim was completely baseless.

Fast forward to 2019. There are now dozens of research papers, hundreds of articles, and hours of video prepared and published by plant biologists and neurobiologists discussing the many facets of plant intelligence. Through rigorous research and experimentation, the following behavioral characteristics have now been established and can be attributed to plants:

• Communication
• Learning
• Problem Solving
• Memory & Memory Recall

Let’s talk about plant communication

One key area of interest gaining quite a bit of support recently is the idea that plants have the ability to communicate with one another, and have the ability to share information and resources between organisms.

There is a growing body of evidence that suggests that plants, trees in particular, can communicate with one another. This communication occurs through underground Mycorrhizal networks, or cobweb-like networks of mushroom mycelial growth that grows around the root structures of trees. These Mycorrhizal networks have affectionately been dubbed the “Wood Wide Web,” and scientists hypothesize that they can be used for anything from nutrient transportation to signaling that a potential threat such as a caterpillar, is nearby.

Essentially, these Mycorrhizal networks are creating an internet-like communication network between trees. These networks may even allow an entire forest to communicate.

Evolutionarily speaking, it makes sense why plants might pursue communication methods. Plants are stationary and don’t have the luxury of running away when predators are near. Nor do they have the ability to go spread their seeds or pollinate the area in which they occupy. In order to combat their mobility limitations, communication would be an incredibly useful adaptation.

With this in mind, the idea of plants forming a symbiotic relationship with nearby fungi to exchange messages and resources is an incredible way of circumventing what some might consider an evolutionary hindrance. But that’s evolution for you…

If you have more questions about communication between trees, we highly recommend this TED talk by ecologist Suzanne Simard

Plants and classical conditioning

Intelligence can’t solely be determined by two or more plants interacting with one another. But what if plants can learn from experiences like Pavlov and his dogs? Can plants be taught?

To find out, a research team from Western Australia University designed an experiment to test pea plants’ ability to respond favorably to a stimulus and reward system. They began by conditioning the plants to associate the breeze from a fan (stimulus) with light (food). Each day the team would turn on the fan at the same time they turned on the lights. This created an association with the plants that the fan’s breeze means food is coming.

Within four days, researchers were 100 percent successful in teaching the plants to respond to the fan without turning on the lights. This means that the plants leaned towards the fan when they felt the breeze without the lights having been turned on. The stimulus alone was enough to cause a response,  just as Pavlov was able to teach his dogs to salivate to the ringing of a bell without providing food – thus discovering classical conditioning.

The goal of the experiment was to prove whether plants could learn through experience, an idea that seemed implausible. Ultimately, the researchers succeeded in not only their experiment, but also in proving that plants can actually learn.

Read all about the research in the world-renowned scientific journal: Nature.

Plant memory

As research and experimentation continue into the mechanisms of plant memory, you can’t help but ask the question, how can something without a brain have memories? Now that studies have determined that plants can indeed learn and create memories, figuring out the “plant brain” question is the logical next step.

But how do we know that plants can generate memories, or better yet, remember things in general? A study published in 2014 took on that very question. It determined that plants can, indeed, make memories, and can display their memory recall though learned response. Better yet, they were able to learn quickly – in as little as one day.

Lack of nervous system aside, the mimosa pudica, or “sensitive plant,” started displaying learned responses in as little as one day. To understand the experiment, you need to familiarize yourself with the mimosa pudica plant and its unique “reflex” that causes its leaves to fold into the stem. This reaction serves it well when grazing animals are nearby, as it can disguise itself.

The experiment was conducted by dropping the mimosa plant 60 times at 5-second intervals using a custom-built elevator-like system, resulting in the plant’s unique folding reflex. After dropping 60 times, the plant stopped folding its leaves. It was as if it knew that the drop would cause it no harm. The experiment included 56 different mimosa plants, most of which exhibited a learned response to stop curling. In essence, the plant was able to memorize the fall and the outcome. It learned that it no longer needed to curl or fold its leaves in response to the action.

Click here to find out more details about the “Plant Drop” experiment.

So, are plants intelligent?

The question as to whether plants are smart is still a hotly debated topic. However, as more research comes in, the more it seems to indicate plant intelligence as a very real possibility. As it stands now, there’s strong enough evidence available right now to suggest further investigation, which means more research is on the way.

So, are plants intelligent? Stay tuned.

If you enjoyed learning about the research behind plant intelligence, then we think you’ll enjoy learning about how plants positively affect people in “Is Biophilia Enough?: Why workplace well-being isn’t just about design.” To discover what plants can do for your space, contact Ambius today.

Article Sources:

1. Plants talk to each other using an internet of fungus
2. The Secrets of the Wood Wide Web
3. The Intelligent Plant
4. Pavlov’s Dog and Pavlovian Conditioning Explained
5. Learning by Association in Plants
6. Sensitive Plant (Mimosa pudica) Leaves Folding Up Video
7. Experience teaches plants to learn faster and forget slower in environments where it matters
8. Can a Plant Remember? This One Seems to- Here’s the Evidence