Let's pretend DNA matching and stuff like that doesn't exist for a moment. What things make you sure you're related to your relatives? For instance, I have curly hair in the front, and straight hair in the back; one of my uncles has incredibly curly hair, and one of my brothers also has curly hair, while the other brother has straight hair. I have my dad's laugh, his handwriting, and we cross our legs the same when we're sitting down. I worry like my mom. I have my grandma's quirky sense of humor and practical jokes, and my grandpa's fingernails and hairline.