The Secret Life of Plants is a quite possibly one of the most engrossing books pertaining to biology and symbiotic relationships between plants and humans. The book, written by Peter Tompkins and Christopher Bird, provides evidence that shows plants can sense the emotions of all living things—whether it’s other plants, fish, animals or humans. Highlighting the famed experiments conducted by Cleve Backster, the book explains that a lie detector and related apparatus was affixed to a plant. The detector measured the plant’s responses to positive emotions, negative emotions, intent-to-harm, and even pain that was inflicted to another organism. To accompany the book, a soundtrack was produced by Stevie Wonder, as well as full-documentary, which you can watch below.