“…Animal Data Tactile behaviors may be used to signal positive (i.e., greeting and play) and negative affective states (aggression) in mammals (de Waal, 1989;Goodall, 1968;Nishida, 1970;Wilson & Kleiman, 1974). Head-to-head greetings as well as head-to-chest greetings and huddling have been observed in wild and captive woolly monkeys (Lagothrix; Defler & Stevenson, 2014). In chimpanzees, Goodall (1968) observed that greetings include touching of the hand, shoulders, back, groin, thigh or genital area of conspecifics, and these were contingent on the length of time the primates had been separated, mutual attraction and mood (Hiraiwa-Hasegawa, 1989).…”