Jessica Chastain felt "invisible" during her difficult upbringing.
The 48-year-old actress - whose single mother Jerri raised her five children alone as she had to move to different homes - has recalled "living in extreme conditions" and the way her family were treated by society as a whole.
Reflecting on how feminism has "always been present" in her life, she told ELLE Spain magazine: "Maybe it's due to my childhood: being raised by single mothers, living in extreme situations where we often didn't even have enough to eat or faced eviction.
"I remember the feeling of being invisible, of feeling like society didn't see us, as if our lives didn't matter.
"I couldn't accept how my grandmother was treated, the burdens and responsibilities placed on her without anyone acknowledging her."
She saw inequality "everywhere", including wages, job opportunities and education.
She added: "From a very young age, I was taught that this wasn't fair, and that idea sank in so deeply that it became part of who I am.
"When I see a form of discrimination, I can't stay silent. My voice comes out; I can't help it. It's what drives me, and it will be an integral part of my work."
Jessica wants to encourage young women to keep working, and not lose sight of how they deserve the "same rights and responsibilities" as men.
She said: "Young women in their formative years right now logically believe they have the same rights and responsibilities as boys.
"However, as they grow up, society will begin to teach them a different story, one that we of my generation have already experienced.
"These girls need to see role models in the media of women who are successful, ambitious, prepared, and, above all, complex professionals."
She noted the importance of girls looking up to "women who demonstrate that their value doesn't depend exclusively on what they see on the outside, but on what they carry within".
She added: "These examples are essential to inspire them, to make them believe that what they want to achieve is possible and that being themselves is their greatest strength."
