The actress Jennifer Lawrence spoke out against gender pay inequality in an essay on Tuesday, describing how she felt when leaked documents exposed by the Sony Pictures hack showed that she had been paid less than her male colleagues on the film “American Hustle.”

In the essay, published in Lena Dunham’s newsletter Lenny, Ms. Lawrence acknowledged that her experience was not exactly relatable — she is the world’s highest-paid actress, according to Forbes — but said that her decision to do nothing was at odds with negotiating tactics used by her male colleagues.

“When the Sony hack happened,” she wrote, “I didn’t get mad at Sony. I got mad at myself. I failed as a negotiator because I gave up early.

“Jeremy Renner, Christian Bale, and Bradley Cooper all fought and succeeded in negotiating powerful deals for themselves,” she wrote of her co-stars. “If anything, I’m sure they were commended for being fierce and tactical, while I was busy worrying about coming across as a brat and not getting my fair share.”