Why can't i grow facial hair?

Well i'm 19 years old, I have pretty big side burns(haven't gotten a hair cut in awhile) but i've never had to shave a day in my life. I have a goatee that's coming along, it's not peach fuzz, but not a full fledged goatee...but no hair ever grows on my cheeks or around my cheek bones. I couldn't grow a beard even if i wanted to, and yet all of my friends have facial hair, why is this?