Walla Zaman Ya Selahy Walla Zaman Ya Selahy "Walla Zaman Ya Selahy" () was the national anthem of the United Arab Republic (UAR), a federation of Egypt and Syria, from 1960. Though the UAR broke up in 1961, Egypt retained the official name of the union until 1971, and the official anthem until 1979. Prior to being adopted as the UAR anthem, it was a nationalist song performed by Umm Kulthum during the Suez Crisis in 1956, known in Egypt and the Arab world as the Tripartite Aggression, when Egypt was invaded by the United Kingdom, France, and Israel. Due to its strongly nationalist
Aggression frequent type in foraging primates. Other questions that have been considered in the study of primate aggression, including in humans, is how aggression affects the organization of a group, what costs are incurred by aggression, and why some primates avoid aggressive behavior. For example, bonobo chimpanzee groups are known for low levels of aggression within a partially matriarchal society. Captive animals including primates may show abnormal levels of social aggression and self-harm that are related to aspects of the physical or social environment; this depends on the species and individual factors such as gender, age and background (e.g. raised wild