"The question is really why do so many women's careers take off just as they have children?" Pike, 35, tells Glamour for its October cover story, in an interview conducted by Gone Girl author Gillian Flynn.
"Is it because you are risking everything in your relationship and the risk-taker in you carries through into your professional life? You have less time to worry and overanalyze – maybe that's it," she says.
Or maybe not.
"Or the huntress instinct to provide for your family is awoken," she adds. "[Either way], with children you spend so much time re-experiencing the world as a child experiences it, and that has a nourishing effect on your imagination – in my job, imagination is key."
The British-born actress had plenty of practice flexing the darker aspects of her imagination while playing Amy Dunne in Gone Girl, which hits theaters Oct. 3.
The film centers on Amy's disappearance and the subsequent belief that her husband, played by Ben Affleck, killed her.
Newlywed Neil Patrick Harris, who plays Amy's ex-boyfriend, also emerges as a suspect – and Pike says the former How I Met Your Mother star was unsurprisingly good at lifting everyone's spirits after some intense filming.
"Ben and I would have these scenes that were very giggly and sort of romantic. And then we'd go to this very dark place," she admits. "I tried to get us out of that. Neil was incredible at that. We were in hysterics in the editing room."
Pike and Harris also filmed a prolonged sex scene together – which ended up not being quite so funny.
"[Director] David [Fincher] left Neil and me alone on that set for like two hours to make sure we could do it," she says. "But when it's just two of you, basically kind of f–––ing on a bed, it feels so inappropriate."