 The prevalence of trichophilia (hair partialism or fetishism) is 7% in the population, and very long hair is a common subject of devotion in this group.Humans, horses, orangutans and lions are among the few species that may grow their head hair or manes very long.Humans are believed to have lost their fur 2.5–3 million years ago as hominids when transitioning from a forest habitat to the open savanna, as an effect of natural selection, since this development made it possible to run fast and hunt animals close to the equator without getting overheated.