A beard is the hair that grows on the jaw, chin, upper lip, lower lip, cheeks, and neck of humans and some non-human animals. In humans, usually pubescent or adult males are able to grow beards. Some women with hirsutism, a hormonal condition of excessive hairiness, may develop a beard. Throughout the course of history, societal attitudes toward male beards have varied widely depending on factors such as prevailing cultural-religious traditions and the current era's fashion trends. Some religions (such as Islam and Sikhism) have considered a full beard to be essential and mandate it as part of their observance. Other cultures, even while not officially mandating it, view a beard as central to a man's virility, exemplifying such virtues as wisdom, strength, sexual prowess and high social status. In cultures where facial hair is uncommon (or currently out of fashion), beards may be associated with poor hygiene or an uncivilized, dangerous demeanor. In countries with colder climates, beards help protect the wearer's face from the elements. Biology The beard develops during puberty. Beard growth is linked to stimulation of hair follicles in the area by dihydrotestosterone, which continues to affect beard growth after puberty.