"I'm a very excited person I think, and I laugh a lot, so maybe that's it," Fanning tells PEOPLE.
The two spent the past few days in Europe as they launch their press tour for the movie Maleficent, out May 30.
Jolie plays the evil sorceress who curses Fanning's Aurora when she's an infant. (Young Aurora, by the way, is played by Jolie's youngest daughter, Vivienne.)
Perhaps it's not surprising, then, that Jolie would act almost maternally toward the 16-year-old star. "When we first met, she gave me this huge hug," says Fanning.
And now? Any secret handshakes?
"I wish!" she says laughing. "I think we're huggers. That was how it all started."