|Rachel McAdams & Martin Sheen|
She said: "Am I still friends with my old boyfriends? Yes, absolutely. There's no one who's ever been significantly in my life for whom I don't have a sort of tenderness because they helped to shape who I am.
"However long someone is in your life, they're there to teach us something and I try to make the most of any relationship."
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The 33-year-old beauty values humor most in a boyfriend and she thinks it is particularly important to be able to laugh at problems.
She added to Britain's HELLO! magazine: "First and foremost, a sense of humor [is attractive]. You can have passion, you can have interests in common and all the other good things. But if it's to be a long-term relationship, then you're going to need something to get you through the trials and tribulations.
"The ability to laugh together and not take anything too seriously is essential. It's a way to connect that forgives a lot of other things and it allows you to move on much more quickly if there's a problem."