Pax was adopted in 2007 at the age of 3 when Angelina and Maddox had been traveling to Vietnam. As Pax grew older, Angelina shared that Maddox and Pax had developed a close bond. At the time, she told People, "Pax is a great kid. When we first met him, we thought he was really shy but after two days at home we discovered he is the loudest member of the family. We don’t know if it’s because he has freedom he’s never had before, but he’s doing great."

As of this writing, Pax is 18 years old and prefers to keep his personal life on the private side. However, he did have a small cameo in 2016's Kung Fu Panda 3, which also starred his mother. In 2015, at just 12 years old, he served as a set photographer for Angelina Jolie's documentary First They Killed My Father.