My hair was straight when I was a child and my dad has 4c hair. I am not into curl typing but just to give you an idea....he has very tiny curls. My mom has straight hair naturally. It did get curly as I grew older. My son's hair is also straight and when it had a bitmore length to it it was still straight unlike my daughter...her hair has a bit of curl and wave to it on the ends. With scrunching she has 2 type curls.