I have fake plastic hair?

So my mum and my grandma have hair that looks and feels like plastic and so does my 2 children and I. I'm a 23 year old black lady. All the women in my family have plastic like hair and I don't know why. It's been passed on from generation and over. Great grandma had it and all the greats there have ever been. It's been passed on for 100's of years. It's not like we can't use shampoo, moisturise or brush it. But if I try gelling my edges, within 15 min, my hair would just shoot up again. It literally can't stay down. It's too curly. And when you pull a strand of my hair, it makes the same noise of when you're wiping/cleaning a window. It feels almost fake. The way it looks as well, is very different from others who have the same hair type. I have 4B hair and I know it'll be harder for people with 3C and lower hair types to understand but if someone tells me why this is then I'll be more than happy