I'm not positive on why, although its strands are not as thick as red hair's.
I find it interesting that brown hair is thicker than blonde but red hair is even thicker.
I used to have bright red hair but as the years have gone by it has become more brown. Interesting, are you aware that you have the second most common hair color now? I wasn't but it doesn't concern me too much, I wonder if it can go black too from brown. The thing is, it can vary, so there's light brown as well as almost black hair. Oh neat, I may wait and see if it goes black then lol! I also notice that my friends brown hair is thicker than my blonde friend's why is that?
Its strands are thicker than those of fair hair but not as much as those of red hair.