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 Sikhism) have considered a full beard to be absolutely essential for all males able to grow one, and mandate it as part of their official dogma.Unlike them, the non-Semitic Sumerian men tended to shave off their facial hair (which is especially notable, for example, in the numerous statues of Gudea, a ruler of Lagash, as opposed to the depiction of the roughly contemporaneous Semitic ruler of Akkad, Naram-Sin, on his victory stele).
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.
However, in cultures where facial hair is uncommon (or currently out of fashion), beards may be associated with poor hygiene or a "savage", uncivilized, or even dangerous demeanor. Beard growth is linked to stimulation of hair follicles in the area by dihydrotestosterone (DHT), which continues to affect beard growth after puberty.
A metal false beard, or postiche, which was a sign of sovereignty, was worn by queens and kings.
This was held in place by a ribbon tied over the head and attached to a gold chin strap, a fashion existing from about 3000 to 1580 BC.
The anagen phase is the amount of time a hair follicle will grow before the hair falls out and is replaced by a new hair.
This in turn determines the length of the hair on that part of the body.
For example, a scientist who chose to remain anonymous spent several weeks on a remote island in comparative isolation.
He noticed that his beard growth diminished, but the day before he was due to leave the island it increased again, reaching unusually high rates of growth during the first day or two on the mainland.
The hairs of a bushy beard will have a relatively long anagen phase.
The hairs of some men have shorter anagen phases and consequently have sparser shorter beards.
The facial hair of most women and children has a very short anagen phase .