Why do some men don't grow facial hair?

I've noticed that many boys don't grow facial hair in their teenage years. Some will only start to grow facial hair when in their early twenties, even when everything else in their body is well developed. Why's that? Is it normal? And shoud they go see a doctor?Why do some men don't grow facial hair?
some have higher male hormones such as testosterone which causes the hair to grow faster and no not a sign in seeing a doctorWhy do some men don't grow facial hair?
they shave...





I shave I'm turning 18 in 10 days, it's personal preference, I don't like scruff on my face, doesn't mean i cant grow facial hair, i just choose not to, like a lot of men my age.
I know a mexican guy and they are usually more hairy and he has hair on his head and that is about it. It is his genetics.
Absolutely normal. I wouldn't bother going to the docs for it, but if you are seriously concerned, you could maybe go, just to put your mind at rest
It's simply determined by ones genetic make up.
Because they are lucky! No they don't need to see a doctor, it's prety normal. Everyone is different. :)
cause theyre genetic mutations and dont have enough hormones to make em a dude... so offically theyre girls
genetics my friend started growing here on his leg this year at 10th of highschool
Maybe cuz of their genetics
maybe they just don't like it