On this day, 35 years ago, August 6, 1990 (June 16, 1990 in the lunar calendar), China's first large-scale survey of sexual civilization ended. On August 6, 1990, the overseas edition of "Outlook" weekly announced that China's first large-scale sexual civilization survey was successful in mainland China. This survey proved that the physiological precocity of mainland teenagers is very obvious. About 54.2% of men under the age of 14 have first seminal emission, and 91.5% of women under the age of 14 have menarche. The precocious puberty of sexual physiology brings about sexual psychology: According to surveys in Beijing, Shanghai, Chengdu, Guangzhou and Xiamen, about half of middle school students have friends of the opposite sex. The survey sampled 8000 urban and rural couples, and only 23% were dissatisfied with their sexual life. However, further investigation and analysis found that in fact, 60-70% of couples are dissatisfied with the process and feelings of their sexual life. Relevant experts believe that this contradictory state is a reflection of the coexistence of conservatism and openness in people's concepts, which shows that there are low expectations for the quality of sexual life and marriage, but potential dissatisfaction has formed. On the one hand, 27% of couples in cities and 50% in rural areas adopt a "let it go" attitude towards discordant sexual life. On the other hand, sexual issues are being paid attention to by more and more people in marriage. The survey involved 15 provinces, cities and autonomous regions across the country, and sampled a total of 23000 cases. The answer sheet recovery rate reached 96%, and the pass rate was 99%. The survey was called "another peak in the history of world science" by overseas sex experts.