When I was a teenager, I lived with a brown capuchin monkey. Among other games, we enjoyed trading: his poker chips for my food. When he was out of poker chips, he would improvise by finding pebbles, paper, toys, and other household detritus to trade. When all was traded into my pile, he would give me his tail, feet, and hands by placing them, one by one, in my mouth. These pieces of him were mine to keep until I chose to release them. While a part was in my mouth, his focus was diffuse and disconnected from me and from himself (perhaps similar to the “trancelike state” mentioned in the article). After I released him, he would refocus on me and begin to negotiate the next exchange. He was an acutely intelligent individual, and I am very grateful for Susan Perry’s field study of capuchins.