I voted No.
My mom relaxes, but I've seen pictures of her from the 60s and 70s with a big, gorgeous fro (and mini-dresses; she looked so fly!) and I'd type her as a 4a/b I guess... and my dad kept his hair very short most of the time, but also from old pics I know that it is not stick straight. I'd guess he's a 2a.
My siblings and I go in order of age from most curly to least curly. I'm the middle kid. My sister relaxes though. If I had her curls I'd be wearing them out all the time. She has these tiny springy coils like another curly on here whose name I can't remember. And my brother lost his hair. So I'm the only actively curly one in the family.
"It is wrong to use moral means to preserve immoral ends." MLK, Jr.