With their supersize brood — six children between the ages of 3 and 10 — it’s no wonder that Brad Pitt, 47, and Angelina Jolie need professional help. But In Touch has learned that one of the nannies regularly seen trailing the clan is, in fact, a therapist, tasked with helping 7-year-old Pax deal with his aggression. “He’s become something of a bully,” a family insider reveals. “He picks on [5-year-old] Shiloh, and even on his big brother, Maddox. He’s really having a tough time getting along with his siblings.”

It’s possible, of course, that some of Pax’s behavioral problems stem from his difficult early childhood. Unlike Zahara, 6, and Maddox, 10, who were adopted as infants, he was more 3 years old when he was adopted, and is still able to recall his hard-knock life in a Ho Chi Minh City orphanage in Vietnam. In the past, Angelina’s been open about the difficulty Pax once had adjusting to his new life. “We’re slowly beginning to build his trust,” she said. “It will take him a while to realize he has a family.”

But his chaos filled current lifestyle is likely also a factor. “He’s having a difficult time with the constantschedule changes,” the insider says, “and with the fact that people stare at him whenever he’s with his parents.” relationship expert Dr. Gilda Carle advises Angelina, 36, to focus on Pax and attempt to discover the source of his anger. “It seems like it’s attention, and maybe answers, that he wants,” she says.