What were you doing when you were 13? New surveys and research show that the younger generation of teens has become a global trend. This is true of developed countries, as well as developing countries, including China. Take a look at the relevant research and surveys.Sexual behavior becomes younger, and China catches up with the world's "trend"In 2019, a study published in the journal JAMA Pediatrics found that 3.6% to 7.6% of boys had had sex before the age of 13. In San Francisco, 5 pe...