New York, Sep 11 (IANS): While verbal and physical bullying decrease as children age, cyber-bullying increases, especially among girls, says a study.

Bullying increases as students graduate from elementary to middle school and, overall, girls are more likely to experience verbal/relational and cyber victimisation than boys, the findings showed.

"Schools will only be free from bullying when interventions are gender- and culturally-sensitive and address all types of bullying," said Cixin Wang, an assistant professor at the University of California, Riverside in the US.

"School-based interventions need to address the differences in perpetrator and victim experiences," she added.

"The key is to use individualised specific interventions for bullying, not a one-size-fits-all approach," Wang noted.

The study is based on data about bullying obtained from 1,180 fifth- to eighth-grade students over three semesters at schools in a mid-western city in the US.

"Bullying decreased over time. However, there was an increase from fifth to sixth grade, which corresponds with the transition from elementary to middle school," the researchers emphasised.

The study appeared in the journal School Psychology Quarterly.