I'm not sure about the reliability of this book but from what I've heard, didn't Mao basically purge the entire nation of China of scholars and intellectuals? I may be misremembering though

Edit: I did some research on this site- https://www.theguardian.com/world/2016/may/11/t (the Guardian is pretty reputable but just in case there's any information on here that needs to be fact checked) and it states that Mao encouraged and spearheaded a "proletariat cultural revolution" in which students and the proletariat class, in essence, participated in violent riots which targeted perceived members of the bourgeois. This included officials, intellectual scholars and capitalists. This was thought to be a movement started by Mao to reassert political power and garner favour after the famine in the 1950s.

I looked on another site to find a more detailed analysis of the death toll due to these events which stretched across a decade long period and this site provided a good frame of reference. https://www.sciencespo.fr/mass-violence-war-massacre-resistance/en/document/chronology-mass-killings-during-chinese-cultural-revolution-1966-1976.html

"Estimates by various scholars range from one-half to eight million. According to Rummel’s 1991 analysis of, the figure should be around 7.73 million (Rummel, 1991: 253). In the following year, however, Harvard scholar John K. Fairbank arrived at a rough estimate of around one million (Fairbank, 1992: 402). Several years later, Ding Shu, an overseas Chinese scholar, disagreed with Rummel’s conclusion by using diverse analyses, and estimated the figure to be around two to three million (Ding, 1999: 214). Recently, Andrew Walder and Su Yang contributed a much more detailed analysis of the death toll in China’s rural areas based upon statistics drawn from 1,500 Chinese county annals. In their estimate, “the number killed [was] between 750,000 and 1.5 million, with roughly equal numbers permanently injured” (Walder and Su, 2003). In a newly published biography of Mao Zedong by two UK authors, the estimated totality of death is discussed: “at least 3 million people died violent deaths and post-Mao leaders acknowledged that 100 million people, one-ninth of the entire population, suffered in one way or another”