Other facts confirm the role of a large penis as a threat or status display toward other men. Recall all the phallic art created by men for men, and the widespread obsession of men with their penis size. Evolution of the human penis was effectively limited by the length of the female vagina: a man's penis would damage a woman if it were significantly larger. However, I can guess what the penis would look like if this practical constraint were removed and if men could design themselves. It would resemble the penis sheaths (phallocarps) used as male attire in some areas of New Guinea where I do fieldwork. Phallocarps vary in length (up to two feet), diameter (up to 4 inches), shape (curved or straight), angle made with the wearer's body, color (yellow or red), and decoration (e.g., a tuft of ur at the end). Embarrassed male anthropologists interpret the phallocarp as something used for modesty or concealment, to which my wife had a succinct answer on seeing a phallocarp: "The most immodest display of modesty I've ever seen!"

Diamond, Jared, the Third Chimpanzee, HarperPerennial, 1992, p. 76.