"It's hard to find people who don't feel like they're in competition with you," she tells Allure in its May issue.
But while Duff, 20, may try to stay out of the fray, she can't help but chat – a little, anyway – about some of her peers.
She dishes to Allure about Lindsay Lohan, Miley Cyrus and Avril Lavigne:
On Lindsay Lohan: "Supposedly, I stole Lindsay Lohan's boyfriend [Aaron Carter.] We were, like, 13! And I've never stolen anyone's boyfriend! I don't know how you do that! . . . She was talking about it and I wasn't. It made us both look bad and put up a big weirdness. Really she was just a girl my age. We are fine now, by the way."
On Miley Cyrus: "We don't have each other's phone numbers. But when she meets me, she's excited. It's cute – I see a lot of myself in her."
On Avril Lavigne: "I said something about how she didn't like her fans dressing like her, and how she should appreciate that because it's a compliment. She called me a goody-goody [Lavigne called Duff a 'mommy's girl' in Newsweek] Everyone is trying to prove who they are, and their position. So, I'm 'the good girl.' She's 'the bad girl' or 'the party girl.' Sarah Jessica Parker doesn't take her clothes off, but she's not a 'good girl.' [Adult actors] don't get tagged like we do."