WHERE DID i GET MY CURLY HAIR FROM?

Why do most of my family members and I have curly hair and lighter skin if we are mexicans? Almost other mexican families have stick straight indian hair and are tan and mine have curly puffy hair and light skin with some light eyes why is that? Don't aztec indians or native american's (which mexicans are) basically in general have very straight hair then why is mine big n curly?