Wild man syndrome experiencing the condition. Some theorists believe that emotions are produced by culture and are not biological. Their emotional diversity across cultures and the way individuals think is based on their social environment and on past and future experience and expectations. Wild Pig syndrome is unusual by Western standards; however, it is common and normal in the Gururumba tribe. This syndrome got its name from the occurrence of domesticated pigs going through a temporary state in which the pig will run wild. With appropriate measures the pig can return to the domesticated pig life among the villagers. This is similar to
Wild horse taxonomists considered domesticated and wild horse two subspecies of the same species, the valid scientific name was "Equus caballus" Linnaeus 1758, with the subspecies labeled "E. c. caballus" (domesticated horse), "E. c. ferus" Boddaert, 1785 (tarpan) and "E. c. przewalskii" Poliakov, 1881 (Przewalski's horse). However, in 2003, the International Commission on Zoological Nomenclature decided that the scientific names of the wild species have priority over the scientific names of domesticated species, therefore mandating the use of "Equus ferus" for the horse, independent of the position of the domesticated horse. Przewalski's horse occupied the eastern Eurasian Steppes, perhaps from the Urals