The `Red Riding Hood` actress has admitted her restricted Pennsylvanian upbringing shaped a nervous attitude towards boys and relationships.
She said: "I grew up in a small town which wasn`t very open when it came to sex and as a teenager I was scared of having sex. In school, most of the girls I hung out with were very uptight about kissing boys, so that shaped my attitude towards sex in a negative way.
"It took a while to overcome that conditioning and feel truly free about my body."
The stunning blonde also confessed that although she is considered one of the most beautiful women in the world she is still to completely accept her body and its desires.
She explained in an interview with LOOK magazine: "I`m still learning how feel more in tune with my sensual side. It`s part of my battle with my own anxieties, but I`m on the right track."
Amanda first realised she had sex appeal when she played a seductress who tries to wreck a marriage in erotic thriller `Chloe`, which she described as "a rite of passage and a very liberating experience."
The 25-year-old star said: "It freed me from a lot of issues that had been holding me back in life. It made me embrace my sexual side and so I`ve felt a lot sexier since making that film."