of course it's not a guarantee. the women in my family are all below 5'4" and I'm 5'7". all my cousins' hair started out blonde and turned auburn, my hair is nearly black. there are no guarantees in genetics.
Absolutely not! Environmental factors are huge in determining this sort of thing (or any thing at all for that matter)
Besides, every condition that can progress can also regress. Losing an arm might be pushing this principle, but with medical science and the rapidly-improving human condition, even a bald man today has plenty of reason for optimism that his hair may one day be full and lush.
who's hair is yours more like?
my dad's family's hair gets nappy, and they all had afro's (80's Black traditional).
mom's had straight black hair.
my hair is straight when its short, but when it gets long it starts curling up. I'm gussing I'm more like my dad's hair.