Skarsgard, 25, is son to Stellan (Thor) and brother to actors Alexander and Gustaf (TV's Vikings) but he wasn't exactly dying to join the family business.
"I wanted to be an actor ever since I was a little kid," he tells PEOPLE in the magazine's new issue, on newsstands now. "But as I got into my teenage years I thought, is it really me wanting this or because I want to follow in my dad's footsteps?"
Skarsgard studied science in high school before deciding he couldn't deny his own passion for acting any longer and that he wanted to pave his own way.
"I've always felt a very strong need to do it myself," he says. "The association with my brothers and my father is already so big, I didn't want them to have anything to do with what I did. I needed them to feel that I am completely responsible for what I do."
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For more from Skarsgard, pick up the latest issue of PEOPLE, on newsstands now
Bonus Skarsgard fact: their family name is wholly original and relatively new.
"We're the only ones with our last name," says Skarsgard. "My grandfather and his brothers came up with it, so we're the only ones who are named Skarsgard, our family and our cousins and stuff like that. A lot of people think that Skarsgard happens to be a common last name, but it's just us."
The Divergent Series: Allegiant arrives in theaters March 18.