Causes of Hair Growth

[Kinky Temples]

A silly question probably. I'm aware hair grows in the form of protien out of the follicle and whatnot, but what causes a baby's hair follicles to thicken until it reaches 2/3/4 years old?

I've been told hair growth is caused by testosterone, but how this is true when considering a 4 year old girl with perfect density is a mystery. From what I know testosterone/DHT is connected with bodily and facial hair, and has nothing to do with scalp hair.

[Dr. William Rassman]

A silly question probably. I'm aware hair grows in the form of protien out of the follicle and whatnot, but what causes a baby's hair follicles to thicken until it reaches 2/3/4 years old?

I've been told hair growth is caused by testosterone, but how this is true when considering a 4 year old girl with perfect density is a mystery. From what I know testosterone/DHT is connected with bodily and facial hair, and has nothing to do with scalp hair.

Hair characteristics are genetic and they are age dependent. Hair is made of protein, that is correct and it is tightly packed together to form the actual shaft.

Proctor and Gample's has an extensive book on hair that's on their website here. (http://www.pg.com/science/haircare/hair_twh_toc.htm)

That should answer quite a few of the questions you've got here.

[Kinky Temples]

The beginning sections talk about terminal hairs in babies. It doesn't explain what causes the thickening though...it's alright. I'll figure out eventually.