Britney Spears grew up in a violent household, her uncle has claimed.
The 'Womanizer' singer - who famously shaved her head and spent time in rehab following a breakdown - reportedly witnessed her father Jamie Spears regularly flying into drunken rages at their family home when she was a small child.
Her uncle Willie Spears - who is Jamie's brother - revealed in Steve Dennis' new book 'Britney: Inside the Dream': "I was at the house and Jamie walked in drunk and called Lynne a bad name. She was in the kitchen drinking water and he grabbed the glass, walked into the lounge and just hurled it. It was rough, but the sad thing is that it became normal life."
Lynne filed for divorce from Jamie in 1980, the year before Britney was conceived after he allegedly cheated on her. Lynne sought a restraining order after fearing the start of divorce proceedings would spark his temper.
However, the pair did not legally separate until 2000.
Willie says the erratic behaviour of his brother - who sought treatment for his problems with alcohol in 2004 - became a "normal" part of his niece's childhood.
He continued: "One time Jamie was drunk and tried to drive off with Britney in the car. She was no more than five years old. I tried to stop him, so I reached into the truck to grab the keys from the ignition and he punched me.
"We got right into it there by the car, fighting in front of her. Britney was jumping up and down, crying. Lynne had to run out to get her inside. We Spears men are known for fighting. If Britney happened to be there, so be it."
As a youngster, the pop star reportedly dealt with the violence by blocking out the incidents.
Willie added: "At first Britney was a scared child and you'd catch her crying but she reached the stage when she just walked off, as if it wasn't happening. And as she got older, she would scream and curse at her parents to get them to stop fighting."
Meanwhile, Britney's former assistant Alli Sims - who has been barred from seeing the singer by Jamie - has spoken out about the singer's relationship with her "controlling" parents.
She said: "Yeah, he definitely said that I can't see her. You know, they're very controlling and that's fine and I just stepped back. I'm not going to fight nine lawyers and parents."