Donald Trump claims that he is very much the same person he was when he was a child. This is probably true as Trump was a rather “nightmare” child who enjoyed bullying his classmates, punched teachers, and threw fits if he didn’t win any game. Pictures of him as a child bear a strange resemblance to the man he is now, the anger and hairstyle of course.

A new biography from Washington Post reporters examines Trump’s life through dozen interviews with people who knew him over the years. According to the biography, a lot of Trump’s behavior can be attributed to his father, Trump Sr, who was a grumpy, authoritarian patriarch who wore suits and ties even when he was at home. Trump Sr. was a very wealthy workaholic before Trump was even born.

And from a young age, Donald Trump try to make neighborhood kids jealous, showing off his Italian racing bikes and elaborate model trains. And those neighbors remembered him well, sharing stories about how he would threaten to call his father and the police if a ball happened to bounce into his parents’ yard.

Dennis Burnham, an old neighbor of Trump, recalled that when he was a toddler, his mother put him in a playpen in their garden. When she returned, she found six-year-old Donald Trump hurling rocks at her son.

Steven Nachtigall, another child from Trump’s neighborhood, said that Trump was a “loudmouth bully” that once jumped off his bike to pummel another boy. The incident was so disturbing it stayed with him for decades. “It was so unusual and terrifying at that age,” Nachtigall, now 68, said.

Trump even admits to being a problem child in school. “I liked to stir things up and I liked to test people,” he proudly said. “It wasn’t malicious so much as it was aggressive.” Trump stated that when he was eight, he was almost expelled for giving his music teacher a black eye ‘because I didn’t think he knew anything about music.”

Charles Walker, his music teacher, denounced that claim. And while on his deathbed,  when Trump was running for President last year, still recalled Trump being a “little s**t.”