The Empathetic Behavior of Plants

Humans would not survive without the interdependent behavior of plants. The root connections of plants allow them to share nutrients, resources, and signals of distress. In turn, we rely on the resources they provide us, just as they rely on each other’s. The survival of plants is required for us to breathe oxygen, supply food, and create medicine. Their alliance helps them survive in harsh conditions, to the same degree that humans support one another. Plant, animal, and human each bare the weight that our counterpart cannot. That ideology supports the life of each species in the ecosystem.

Plants have a complex form of communication and an exchange of recourses that are hidden in the soil. It all sounds very bizarre, with their seemingly basic needs of survival. Yet, there is more to them than meets the eye.

Britt Holewinski explains their bond in the National Forest Foundation article, “Underground Network: The Amazing Connections Beneath Your Feet.” The author describes to readers that fungi create a “mycorrhizal network,” a web of roots that attach to trees and various plants. These roots allow them to share nutrients, water, and even communicate to one another through the webs.

The plants work as a community, giving and sharing resources to promote the survival of the ecosystem. The network allows for the benefit of all the living organisms attached. As Holewinski remarks, plants can interpret chemical distress signals in other plants and respond accordingly. They can even alert for danger, an action that doesn’t only benefit the individual plant.

Although their behavior may sound shocking, it makes sense that they have an almost caring nature for each other. They use each other to survive, similar to how humans do. We provide support for each other, not just for individual benefit, but for our community. The prosperity of the community then turns to help us when we need it.

In humans, we are driven to help by the motivation of emotion. Empathy is what pushes us to aid others in distress. The concept that plants can feel this emotion might be striking, but the behavior that plants display is so similar to empathy seen in human behavior. Recognizing what empathy is will help to better understand the behavior that follows it.

The topic and definition of empathy varies depending on the source. Benjamin M.P. Cuff in the article, “Empathy: A Review of the Concept,” shares his thoughts while debating the various components of the emotion.

To start, it must be triggered by a stimuli. This could be witnessing an expression, a situation, or signaled through communication. In addition, he explains how empathy is separate from sympathy. Sympathy requires understanding the others emotion or situation while empathy is feeling it for yourself. This could also be defined as cognitive empathy, the understanding side, and affective empathy, the ability to feel it.

However, empathy is not the exact replica of the emotion another person is feeling, but the similarity to it. The depth and ability of empathy ranges from person to person. This could cause a reaction and an act of altruism, but it is not required.

Overall, it is summarized as:

Empathy is an emotional response (affective), dependent upon the interaction between trait capacities and state influences. Empathic processes are automatically elicited but are also shaped by top-down control processes. The resulting emotion is similar to one’s perception (directly experienced or imagined) and understanding (cognitive empathy) of the stimulus emotion, with recognition that the source of the emotion is not one’s own.

In the case of plants, the feeling of emotion is not something that can be scientifically tested. Even people themselves can only truly express their feelings through verbal communications. The best way to interpret emotion in plants is through behavior. With their giving nature, the sharing of plant resources appears to be altruistic.

Altruism is a key to viewing behavior caused by empathy. In the Stanford Encyclopedia of Philosophy, author Karsten Stueber describes the link between empathy and altruism in their entry, Empathy. Stueber shares the findings of Social Psychologist C.D. Batson. He developed the “altruism-empathy thesis;” a theory stating that empathy causes altruistic tendencies. Stueber described that, “empathy/sympathy does indeed lead to genuinely altruistic motivation, where the welfare of the other is the ultimate goal of my helping behavior.”

Moreover, animals are seen as having these same traits. In a classic psychological experiment done by George E. Rice and Priscilla Gainer, albino rats were studied to see if they can express altruistic behavior. The 1962 journal, “Altruism” in the albino rat, narrates their experiment. The researchers used the following definitions for altruism:

Webster (1941) defines altruism as “regard for and devotion to the interests of others.” The authors felt that altruism could be operationally defined as “behavior of one animal that relieves another animal’s ‘distress.’”

The study was done by placing one rat in an elevated chamber with a system that shocked it periodically. A second rat was placed at the bottom with a bar that could be pressed to stop the shocks and lower the rat from the chamber. When the rat in the chamber was shocked, it would show signs of distress, and the rat at the bottom was tested for whether it pressed the bar or not. This would prove the second rat was alleviating the first rat’s distress.

One test group had rats trained to press the bar, and the second test group contained rats with no training. In both study groups, the rats pressed the bar nearly the same number of times. Rice and Gainer concluded that the albino rats had altruistic tendencies after seeing a fellow rat in distress.

Using Rice and Gainer’s definition of altruism, plants and rats have a very similar response to sensing one of their kind in danger. They each administer a response to alleviate their counterpart. Plants can be seen having the same idea of using their resources to aid a distress signal. In plants, it goes further, with even fungi and trees working together to promote the ecosystem’s health.

In addition, with both humans and animals, behavior is used as an identifier for emotion. A person may say what they are feeling, but it’s only their actions that truly prove it. You can view their expression, body language, and actions to help the person in distress. The albino rats were viewed in the same context.

As hard as it is to imagine, plants have nearly identical behavioral responses compared to these complex organisms. Plants even have shown levels of intelligence and caring behavior through their actions, further displaying what we call empathy in people.

Looking back at the National Forest Foundation article, “Underground Network: The Amazing Connections Beneath Your Feet,” can give us a deeper explanation of the mycorrhizal network. The mushrooms survive underground by connecting to the roots of nearby trees. They are fueled by the carbon and sugar, made by photosynthesis, from the trees, and, in return, supply the trees with minerals needed to survive.

Author Britt Holewinski explains that trees use this link to connect with other, neighboring trees as well. Trees that are lacking proper nutrients can send distress signals, allowing healthy trees to respond and send resources like carbon, water, and minerals to them. The mushrooms can benefit as well, taking a percentage of nutrients sent in these exchanges. Younger tree saplings profit from this link often, as Holewinski explains:

For saplings growing in particularly shady areas, there is not enough sunlight reaching their leaves to perform adequate photosynthesis. For survival, the sapling relies on nutrients and sugar from older, taller trees sent through the mycorrhizal network.”

As the saplings have nothing to provide for the full grown tree, the act appears to be selfless. The saplings without proper resources send distress signals to alert others of their unhealthy state, and healthy trees can immediately respond. It’s an incredibly helpful link. The well sustained trees have no other reason besides a helping hand to send support to the sapling. The idea is very endearing, picturing how nature works together.

The distress signals sent by plants seem to be selfless acts, too. Distress signals sent by plants is explained in more detail by Hirokazu Ueda in the journal, Plant Communication: Mediated by individual or blended vocs? The authors studied “volatile organic compounds,” defined as “airborne signals.” They can be used for a range of reasons, such as attracting pollinators or alerting nearby plants of incoming danger. The plants alerted of the danger can prepare for consequences, increasing the production of defensive chemicals.

After analyzing plant’s capacity to alert for danger and transfer resources, the plants sending information or nutrients have very little benefit for themselves. A plant that provides minerals to a plant in need has no gain, just as the plant alerting for danger has no benefit for themselves. In the far future they may be able to have an equal exchange of resources, yet there is no mutual benefit in the moment. In humans, this kind of selfless act is related to empathy. Behavior displaying generosity for someone in danger or a state of distress is an emotional response. It begs the question of what plants are capable of.

Plant intelligence is explored in “New Research on Plant Intelligence may forever change how you think about plants,” from The World. The author explains the findings of researcher and animal biologist, Monica Gagliano. She studied the mimosa pudica plant, a fern-like plant that closes it’s leaves when it senses contact. Gagliano repeatedly dropped the plant without harming it. At first, it would close on impact. After a few more falls, the plant would stop responding to being dropped. She shook the plant to see if it simply stopped reacting to any danger, yet it closed at this action. Weeks later, she repeated the dropping action again and the plant still refused to close.

The researcher concluded that the plant had a learning ability, a sign of intelligence required for an emotional capacity. It remembered that falling would not harm it, and stopped reacting to the action. Other forms of contact still triggered it to respond, so it must have learned that it was specifically safe when Gagliano dropped the plant. Even without neurons, they show behavior that is linked to processing information, remembering the information, and enacting it. It’s a learned response.

Plant intelligence and memory introduces a new perspective on their capabilities. Furthermore, the idea is another similarity to humans. It takes a level of intelligence to care for another being. Along with a plant’s selfless behavior, it appears to be so shockingly similar to people. It could be possible for plants to remember their own distress in the past, and reflect it on the current situations of their neighboring species.

Moreover, an individual plant may not have a brain, although, the entire system is strikingly like a human neural system. Suzanne Simard, author of Finding the Mother Tree, shares her findings from many her explorations, focused on studying the connections of plants. Her biggest finding was about Douglas-fir trees, or “Mother Trees.” Without the Mother Trees, the entire ecosystem would collapse. Their roots are a large source of nutrients for the surrounding environment. It’s the network it creates that is truly incredible. Simard says during one expedition:

I made a map, Mother Trees, saplings, seedlings. Lines sketched between them. Emerging from my drawing was a pattern like a neural network, like the neurons in our brain, with some nodes more highly linked than others. Holy smokes. If the mycorrhizal network is a facsimile of a neural network, the molecules moving among the trees were like neurotransmitters.

Simard continues to debate the abilities of plants after making the astounding discovery. She wonders of the limit of their intelligence, and how identical the network really is to the human brain. It opens a world of new questions and possibilities waiting to be discovered. With such an identical similarity, it’s possible the entire system could reach certain capacities of a human brain.

The behavior of plants and their potential for higher intelligence is in line with what people define as empathy. As bizarre as it sounds, plants match the characteristics we see as having empathy in humans. They each learn from past experiences and have a system of processing and sharing information, communicating what they learn. Both plant and human display acts of selflessness, sharing resources when they find one of their kind in harm. In both humans and plants, connections are used for the survival of the community. They help each other in order to have a thriving environment.

Furthermore, plants use this link to increase their rates of survival, and humans use their connections to improve life as well. We care about people for the survival of our loved ones and community, whether it’s conscious or not. Helping one another is a skill to defend our species against sickness and dangers in our society. That mentality can profit to the person sharing compassion, hoping it benefits them in the long run, with others having their back when they need it. Plants are not much different in their generous ways of life.

The consciousness of a plant is seemingly necessary for an emotional ability and access to empathic feeling. The consciousness of plants is discussed in the article “Plants Neither Possess nor Require Consciousness” by Lincoln Tiaz, Daniel Alkon, and many following authors who claim plants cannot be deemed conscious due to their lack of a brain and sensory systems. They explain that plants have not followed the process of evolution that animals go through to access higher levels of intelligence. While plants do lack the actual components that require a conscious mind, they have multiple cognitive abilities involved in learning, perception, and sharing tendencies. The behavior that plants display is surprisingly consistent with empathy in humans.

The article, “Multiple control levels of root system remodeling in arbuscular mycorrhizal symbiosis,” by Caroline Gutjahr and Uta Paszkowski explains a specific type of myccorhizal connection. They mention “arbuscular mycorrhizal symbiosis,” a type of fungi connection that penetrates the cells in the roots of plants, allowing them to exchange information and nutrients through this lifeline.

The plants and fungi, or mushrooms, each benefit greatly from this connection; it is seen as a healthy relationship to provide prosperity to an environment. The authors describe that the mushrooms collect nutrients from the plants, like carbon, taking a cut for themselves to ensure survival, then return phosphate and nitrogen to the plants. The elements aid plants in their growth, specifically with lengthening roots and creating more branches, allowing them to absorb even more minerals from the soil.

While this partnerships seems to be just a lucky deal, Suzanne Simard discovers the social side of this relationship in her book, Finding the Mother Tree. The author describes the community plants form from this link, providing each other with the proper nutrients when a plant sends a chemical distress signal through the mycorrhizal network.

Simard realized a strange relationship between two plants, studying the link between birch and fir trees. She found that they exchange carbon throughout the year. Fir will provide carbon to birch when the tree is in it’s best thriving season, and birch will do the same in it’s own best season. With research, she discovered that fir trees are mostly relying on birch, as birch could sustain itself, alone, without the help of fir trees. It seems that fir was only giving carbon to birch to return the favor. Simard questioned if the relationship has any extra benefits since this exchange appears to be more one-sided.

This inspired her further studies on how much aid trees will provide each other through the mycorrhizal connections. Simard’s next research focused on fir and pine trees. She infested a Douglas fir tree with spruce budworms, a species that attacks the tree, eventually killing it. Not only did she discover that the fir trees released a large amount of carbon to their neighbors, but the pine trees formed “defense-enzymes,” just as fast as the fir trees had to attack the infection.

The creation of defensive-enzymes in the pine trees is truly amazing, which Simard explains is used to create better resistance to disease, and could be passed down to offspring, ensuring their survival. This goes further than just a mutualistic relationship, or a simple chemical reaction. Humans create defenses such as this in the form of a vaccination. We want our new generations to be healthy and prepared for the sicknesses that affected us.

Not only that, but the discoveries brought up a lot of questions for Simard at the idea of a familial relationships in trees. The infected trees also sent carbon to specific neighboring trees, like younger saplings, as they were dying, which the author debates as an “inheritance.” The Douglas firs could be sending out the last of their resources as they decay, supporting younger trees to grow in their absence. She later finds that the Douglas fir trees can recognize their kin and “favor” them, sending extra carbon, iron, and other valuable nutrients to those connections. They can identify their “relatives” using “kin-recognition molecules.” The younger trees end up with more mycorrhizal connections and resources due to the help of their ancestors.

Simard remarks about both discoveries:

Over millions of years, they’d evolved for survival, built relationships with their mutualists and competitors, and they were integrated with their partners in one system. The firs had sent warning signals that the forest was in danger, and the pines had been poised, eavesdropping for clues, wired to receive messages, ensuring the community remained whole, still a healthy place to rear their offspring.

The forest remarkably resembles a human community. Some may argue it is just a survival mechanism, yet human care is displayed for the same reason. A community such as this supports one another for the benefit of neighbors and future generations, just like people. Plant behavior shows incredible signs of care and empathy for the struggling organisms in their environment.

The most astounding research for further intelligence and cognitive capabilities in plants comes from the Journal of Comparative Psychology. The text, “(Re)claiming plants in comparative psychology,” written by Umberto Castiello, explains the many similarities in human and plant intelligence. The author calims that plants have embodied cognition, or “a kind of situated cognition that assigns cognition to parts of the body other than to the central nervous system.” As well as extended cognition, or cognition that “extends beyond the physical boundaries of the organism,” and enactivism, the ability to engage with the environment and form relationships.

Even without a central nervous system, they have amazing capabilities. Castiello discusses these more in depth, acknowledging their abilities. As mentioned before, plants can recognize their own species and communicate with them, even creating family-like communities. Plants have been seen retaining a short-term memory, learning when stimulation is harmful or not. They make decisions based on risk factors in their environment, like choosing to grow roots in different types of soil or “moving” to more or less shaded area. Plants even interact and send signals to entirely other organisms, like pollinators, too attract them in yet another interdependent relationship.

Overall, the behavior of plants is so much more than just a series of instincts. They appear to have conscious abilities in recognizing when a neighboring tree is a relative, or knowing when they must protect their younger generations. In reality, at a base level, animals and humans can be seen as having simple chemical reactions just like the average perception of plant habits. Both plant and human display actions of caring for their counterparts, alerting for harm and sharing the extra profits they carry to those in need. The relationships that plants form is so alike to the communities of humans, and our families. The behavior is remarkably similar to human empathy.

References

Holewinski, B. (n.d.). Underground networking: The amazing connections beneath your feet. National Forest Foundation. Retrieved 13 October 2022.

Cuff, Benjamin M.P., et al. “Empathy: A Review of the Concept.” Emotion Review, vol. 8, no. 2, 1 Dec. 2014, pp. 144–153. Retrieved 13 October 2022.

Stueber, Karsten. “Empathy.” Stanford Encyclopedia of Philosophy, Stanford University, 27 June 2019. Retrieved 17 October 2022.

Rice, G. E., & Rainer, P. (1962). “Altruism” in the albino rat. Journal of Comparative and Physiological Psychology. Retrieved 17 October 2022.

Ueda, H., Kikuta, Y., & Matsuda, K. (2012, February 1). Plant Communication: Mediated by individual or blended vocs? Plant signaling & behavior. Retrieved November 7, 2022.

New Research on Plant Intelligence may forever change how you think about plants. The World from PRX. (2014, January 10). Retrieved November 7, 2022.

Simard, S. (2022). Finding the mother tree. Random House US.

Tiaz, Lincoln, et al. “Plants Neither Possess nor Require Consciousness – Sciencedirect.” Science Direct, Aug. 2019. Retrieved November 29, 2022.

Paszkowski, U., & Gutjahr, C. (1AD, January 1). Multiple control levels of root system remodeling in arbuscular mycorrhizal symbiosis. Frontiers. Retrieved November 21, 2022.

Castiello, U. (2021). (Re)claiming plants in comparative psychology. Journal of Comparative Psychology, 135(1), 127–141.