Are plants conscious and do they feel pain? | The Economist

TL;DR

Plants likely have sentience and intelligence but probably don't feel pain, as pain offers no adaptive benefit to immobile organisms.

Key Points

• 1.Plants display surprising sensory capabilities that suggest intelligence. They can mimic the leaf shape of host plants, detect caterpillar sounds and release toxins, hear water in pipes, and may use echolocation to locate poles before touching them.
• 2.Plants can be anesthetized just like humans. A Venus flytrap placed in xenon gas stops responding to stimuli, raising the question of what state is lost — suggesting plants have at least two modes of being, one of which resembles consciousness.
• 3.Plants can learn and remember for up to 28 days. Mimosa pudica, when repeatedly shaken without harm, stops reacting defensively and retains that learned response for a month, challenging the assumption that neurons are required for memory.
• 4.Bioelectric fields, not neurons, may store plant memory and behavior. Scientist Michael Levin at Tufts demonstrated this using planarian worms: conditioned lessons survived decapitation and head regrowth, proving information can be held in the body, not the brain.
• 5.Plants probably don't feel pain because pain isn't adaptive for immobile organisms. One plant neurobiologist argued that pain evolved to trigger escape responses — useless for plants — so while they may sense being eaten, it likely doesn't hurt them.