Charlize Theron and Seth MacFarlane
05/16/2014 at 03:00 PM EDT
Even though she now has a young child, Charlize Theron
says won't be sheltering him from the darker things in the world, nor will she be shying away from taking tougher roles that allow her to explore them.
"I think it's a personal thing, but for me having a child only emphasizes how much more I want to explore real issues and things that really matter, and darkness is one of those things that I don't think that I can veer away from just because I have a child," Theron, 38, told reporters Thursday at the world premiere of her latest film
, A Million Ways to Die in the West
in Westwood, California, where she walked the red carpet with steady date Sean Penn
by her side.
Theron, who stars in the raunchy comedy western, and who adopted son Jackson
, now 2, in 2012, says becoming a mother makes her want to have a stronger understanding of why people behave the way they do.
"There are things that he's never, never going to see, but I feel like that creativity and that interest – when you have a child you become almost more obsessed with wanting to know why people do bad things," she said, laughing. "It doesn't at all make me want to go, 'I'm just going to close my eyes and be naïve about it.'"
For now, the South African-born actress and Academy Award winner
says her priorities are parenting, which far outpaces her acting. She will leave her work and character exploration on the set.
"Obviously he's not going to see any of that stuff until he's way older, and my work really is my work and then he's that priority," Theron told PEOPLE. "My work comes way below him so, even though I have all of those interests and I want to go and explore all of that stuff, it's when I have time for that."
Reporting by REAGAN ALEXANDER