The Bonobos of the Congo Bonobos demonstrate a wide variety of sexual interactions, including face-to-face copulation, kissing, and sexual interaction among same-sex pairs (Fruth & Hohmann, 2006; Parish & de Waal, 2000). Sexual behavior is not limited to reproduction; it seems to play an important role in maintaining peaceful relations among members of the bonobo group. As Frans de Waal (1995) wrote, “For these animals, sexual behavior is indistinguishable from social behavior.”
FINBARR O’REILLY/Reuters/Corbis