The Soul of an Octopus: A Surprising Exploration into the Wonder of Consciousness

by Sy Montgomery

Jackie sniffs the water. “He smells stressed,” she announces. The water in the bag gives off the scent of geraniums. Jellyfish also smell like geraniums when distressed, Jackie explains. But that varies with the species. Stressed anemones give off a sour, salty smell.

Human tears of intense emotion are chemically distinct from tears produced by eye irritants; tears of both joy and sorrow contain prolactin, a hormone that peaks in men and women during sex, dreams, and seizures, and is associated in women with the synthesis of breast milk.