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.
Big hair
Many people of various ethnicities throughout the world have naturally voluminous hair. For these people, "big hair" is not a deliberate fashion statement requiring any particular technique to achieve, but rather the default state of their hair. Some 60 percent of the world's population has naturally curly hair, which tends to be more voluminous than straight hair.