Human hair growth
The three stages of hair growth are the anagen, catagen, and telogen phases. Each strand of hair on the human body is at its own stage of development. Once the cycle is complete, it restarts and a new strand of hair begins to form. The rate or speed of hair growth is about 1.25 centimetres or 0.5 inches per month, or about 15 centimetres or 6 inches per year.
Hair theft
Hair theft has been a recurrent problem in various parts of the world where human hair is in demand either for commercial products such as wigs and hairpieces, or for sexual fetishes. As hair has a high commercial value – in the mid-19th century it was regarded as worth twice its weight in silver – opportunist thieves have targeted long-haired women, and less commonly men and children, with the aim of stealing their hair. Hair thieves have typically sought either to surreptitiously cut off hair in public places, or have mugged people and shorn their heads. The crime of hair theft has been widely reported in North America, Europe, Asia and Australasia over the course of at least 300 years.