"I was told every day at school that I was ugly. And that no one wanted to be my friend. The most cruel things," Chastain tells Glamour in its November cover story. "If I can do anything to help young girls and to be a cheerleader for people who sometimes have low self-esteem, I want to do that."
Chastain, 37, is also directing this supportive energy to fellow actresses and female writers in the business.
"I'm really, really supportive of women in Hollywood. I love Meryl Streep. She's such an incredible actress. But I feel like she's the only one in her age group who gets those parts," the Zero Dark Thirty star says. "Why isn't Viola Davis a lead in a film? She's one of the greatest actresses alive. And where are the Asian actors and actresses? I'm not saying, ‘We don't want movies about men.' I'm just saying, 'Come on, all the men I know love women. So let's also have some stories about these women.' "
Tom Munro / Glamour
The actress herself hasn't had too much trouble landing powerful parts in her short screen career. Chastain didn't receive her first movie role until 2008. In six short years, she has starred in memorable movies like Tree of Life and The Help, and has earned two Oscar nominations. While some may call Chastain a late bloomer to film acting, the actress wouldn't want it any other way.
"I would have been a disaster. If I was 19 and I had the attention that I'm getting now, I would have just said stupid things. I would have partied more," Chastain says. "All these expensive dinners and people giving me champagne? All these stupid things that we criticize 19-year-olds for doing when they're famous, I would have done."
A more mature Chastain is now preparing for one of her busiest years yet, and she shows no signs of stopping. Chastain has another three films slated for 2015 and is looking forward to bringing more strong, realistic women to the big screen in the future.
"I think to play a female hero without faults is actually doing a disservice to women. I think it's more interesting to see women on-screen with flaws," she says. "Then it's not this unreasonable expectation that society then would put on you: 'Well, a strong woman can't be like this….' "