But as order broke down, Mr. Xi, like many youths, spent little time in class. Mr. Xi and a friend “would hang out all day,” Ms. Qian said. After fleeing their home, he, his mother and his siblings took refuge at the Central Party School, an academy for officials. “We grew up in a highly abnormal environment,” Li Xiaobing, a classmate at the August 1 School, recalled on a school alumni website.

The purges, zealotry and mass strife that Mao unleashed during the Cultural Revolution left a lasting mark on every Chinese leader who has succeeded him. But Mr. Xi stands out because he is the first party chief from the generation of the Red Guards — the youths who served as Mao’s shock troops — and because he fell so far before beginning his trek to power, from a family in the party elite to an unmoored life as a teenage political pariah.

Some of Mr. Xi’s critics argue that his experiences during the Cultural Revolution inform his authoritarian ways. But the imprint of that time was more complex than that, said Patricia M. Thornton, a professor at Oxford who is researching the Cultural Revolution and its legacy.

Mr. Xi’s generation venerated Mao, she said, but his family suffered in the violence that Mao unleashed, and Mr. Xi’s outlook is rooted in an elitist rejection of that turmoil.

“Xi got to see both sides of that time, which is one reason I think he’s such an interesting character,” she said, “but that’s also why he’s so difficult to read.”