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Shirley MacLaine Explains Why She Believes in 'UFOs and Reincarnation': 'I'm Just Ultra-Curious'

Nigel Smith

At 85, Shirley MacLaine believes in what she believes in — and doesn’t care what anyone thinks.

The Oscar-winning actress is just as known for her bestselling books as she is for her roles, having authored 10, including the 2016 memoir Above the Line, in which she detailed her firm belief in reincarnation. In it, she goes into detail about her past life in Atlantis 2 million years ago.

“I’m studying what it means to be human,” MacLaine, who also believes in aliens, tells PEOPLE in this week’s issue. “That’s why I’m so interested in UFOs and other civilizations. They’re there! So what can we learn from them?”

“Sometimes I’ve [been mocked], especially my discussions about UFOs and reincarnation. But, okay, let’s discuss it,” she continues. “The more we discuss it, the less grounds for humiliation it serves. That’s never bothered me much anyway… I just love the study of it. I’m just ultra-curious about everything.”

RELATED: Shirley MacLaine Says She Has a ‘Perfect Life’ at 85: ‘I Eat What I Want, I Sleep When I Want’ 

Shirley MacLaine | Chris Pizzello/Invision/AP

For more about MacLaine, pick up this week’s issue of PEOPLE, on stands Friday.

That curiosity also extends to her acting career, which she says keeps her “bright.”

Most recently, MacLaine’s starred opposite Amanda Seyfried in 2017’s indie drama The Last Word, and traded jokes with fellow Oscar winner Jessica Lange in 2016’s comedy Wild Oats.

“I learn so much about what I don’t really know every time I’m on a movie,” she says.

She continues, “I don’t want to quit acting — I really don’t. Even at my age, I have four pictures to do next year. I think [some] costars are surprised I’m still walking upright.”