School victimisation and perpetration rates change in frequency with age. However, findings vary by study, gender, and type of bullying, especially offline and online. We provide a comprehensive analysis of age trends by analysing data from 3 large-scale surveys: Health Behaviour in School-age Children (HBSC), EU Kids Online (EUKO), and Trends in International Mathematics and Science Study (TIMSS). Age trends were classified as U (up), S (same), D (down), P (peak), or V (trough). Findings from HBSC and TIMSS confirm a general D trend for victimisation, especially for boys, with rather more P findings for girls. Findings from HBSC and EUKO confirm mainly P (more girls) or U (more boys) trends for bullying perpetration. For both victimisation and perpetration the gender differences are most marked in the last 2 survey periods of 2013/14 and 2017/18. Age trends online are more varied than online, Cyber victimisation appears to decline less often than general victimisation, but girls more than boys show a P (peak) age trend at 13 years in HBSC data. Findings are discussed in relation to theories about the age changes, and the gender differences in relation to both timing of puberty, and interest in social media sites.

学校受害和犯罪率随着年龄的增长而变化。然而，研究结果因研究、性别和欺凌类型而异，尤其是线下和线上。我们通过分析 3 项大型调查的数据来提供年龄趋势的全面分析：学龄儿童健康行为 (HBSC)、欧盟儿童在线 (EUKO) 和国际数学和科学研究趋势 (TIMSS)。年龄趋势分为 U（上升）、S（相同）、D（下降）、P（峰值）或 V（低谷）。HBSC 和 TIMSS 的调查结果证实了受害的总体 D 趋势，尤其是男孩，而女孩的 P 发现更多。HBSC 和 EUKO 的调查结果主要证实了欺凌行为的 P（更多女孩）或 U（更多男孩）趋势。在受害和犯罪方面，性别差异在 2013/14 和 2017/18 的最后两个调查期最为明显。网络上的年龄趋势比网络上的年龄趋势更加多样化，网络受害似乎比一般受害的下降频率要低，但在 HBSC 数据中，女孩比男孩更多地表现出 P（峰值）年龄趋势，即 13 岁。研究结果与有关年龄变化的理论以及与青春期时间和社交媒体网站兴趣相关的性别差异进行了讨论。