A beard is the hair that grows on the face of a human, but excludes the head, eyebrows and moustache. The ability to grow a beard is a secondary sexual characteristic of males, which develops at puberty due to the release of testosterone from the testes. The rate of growth is related to testosterone production, and as testosterone levels drop in old age with the andropause, beard growth and its density also decrease.
It is not possible to judge a man’s potency by the thickness of his beard as different genetic and racial factors also affect its growth, but the more a man thinks about sex, the faster his facial hair grows. Thinking about sex increases testosterone production, which increases beard growth.
The attitude towards beards differs amongst cultures, religions and personal tastes. Beards can also come and go with fashion trends. There are many different ways of styling the beard and accompanying moustache that have been named, such as goatee or soul patch. Certain professions require a man to be clean shaven whilst others generally expect it. Some men require daily shaving to remain clean shaven. Stubble is beard hair one or two days after shaving. It is long enough to be seen but not thick enough to cover the skin underneath.
A beard in females is due to a hormonal imbalance, particularly around the time of menopause.