heat index," movie star gabrielle union, confessing she was once a so-called mean girl. And now says she's not anymore. And abc's linsey davis has the story for us. Reporter: There's a reason... See More
heat index," movie star gabrielle union, confessing she was once a so-called mean girl. And now says she's not anymore. And abc's linsey davis has the story for us. Reporter: There's a reason gabrielle union is so convincing in her roles as a mean girl. Why do you have to be so mean? Reporter: The actress admits she wasn't just playing a role. She was a mean girl in real life. Something she acknowledged accepting the essence fierce and fearless award. I lived with the negativity inflicted on my sister actresses, or anyone who I felt shine diminished my own. Reporter: She was fueled by the limited number of roles for actresses. I took joy on their pain and tap danced thr own misery. Reporter: Oprah said she was so inspired by union's transformation, that she's going to talk to black actresses about the unique challenges in hollywood and the propensity to become mean. You're supported in tearing other people down. If there's a form for it, there's a huge spotlight on you to do that. Reporter: The mean girl spirit isn't a black or white issue. It's so pervasive in our society, there's a movie called "mean girls." Get in, loser. We're going shopping. Reporter: It's quite evident in reality tv. Tamara, still the queen of mean. Reporter: For african-american actresses and talent, there's not a lot of work. That can make people desperate. And that's where you get the not so kind behavior. Reporter: Union says she's changed hermine girl ways. I decided I wanted more. And that I deserved more. Reporter: She credits a.J. Johnson, her fitness trainer and life coach, for inspiring her to do it. As soon as we started to do the work, the mean started to dissipate. And the sweet, loving girl you know now is what came to be. Reporter: So, the next time you see gabrielle union acting like this -- we'll beat you. And we're going to be better. Reporter: Hopefully, it will be just that, acting. Gabrielle union will star in an original movie premiere of "being mary jane" on b.E.T. How courageous of union to speak out. She did it. She was at a party. And she had been tearing this other woman down. And a.J. Pulled her aside and said, what did you gain? Is your house bigger? Did you get the guy? And she was like, oh, true. She has a lot of power. She owned it. And the episode of oprah's next chapter, black women in hollywood, reairs this sunday on
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