The 'Hero' singer - whose mother is Irish-American and her father was an African-American of Venezuelan descent - claims she never fitted in at school because of her heritage, leaving her very insecure about the way she looks.
She said: "I am very insecure about my looks, and I always have been because of being mixed race. It's not so weird now, and everyone's accepting it in a big way, but as a child I felt very, um, out of place and didn't feel pretty.
"When you grow up with that type of insecurity you don't always feel pretty."
Mariah began to realise she was different from other children when she took her white best friend on one of her weekly visits to see her father.
She told Observer Woman Magazine: "She got out of the car and went up the stairs to his house and he was over 6ft tall and very handsome, but to her he must have really been scary because I don't know that she'd ever seen a black man before. And she looked at him, her mouth went open and she started screaming and crying.
"I think he was trying to make me feel better and calm her down, but it didn't work. You never know what people say in their houses about different races. So my mother took her home and I went up the stairs with my father."