Birth Cohort Effects, Regions Differences, and Gender Differences in Chinese College Students' Aggression: A Review and Synthesis.

Lei et al. (2019) pooled every Chinese study that measured aggression in college students. They tracked how scores changed from 2003 to 2017.

The team looked at physical fights, verbal attacks, anger, and hostility. They split the data by birth year, region, and gender.

Aggression scores dropped hard. The average student in 2017 scored one whole standard deviation lower than a 2003 student.

The fall was sharpest for hitting and yelling, for men, and for students in eastern cities.

Zhao et al. (2024) and Kang et al. (2015) both built new Chinese rating scales. Their work says the tools are sound, so the drop Hao saw is probably real, not a measurement glitch.

The older tools still work, but you now need local norms. A score that looked average in 2005 looks high today.

No other meta-analysis has tracked college aggression this long in China. The downward slope lines up with global youth-violence trends.

If you screen Chinese college students for behavior problems, dust off the 2005 norms and you will over-flag kids. Use the 2017 means instead. The same score that once marked risk now sits at the new average, so you save time and avoid false positives.