Stalking was often an extension of bullying, researchers said
Stalking by children and teenagers tends to be significantly more violent than that carried out by adults, Australian research has suggested.
Psychiatrists looked at nearly 300 so-called juvenile stalkers and found they rarely acted because of infatuation for their victim, as often assumed.
Instead stalking was an extension of bullying, or a reaction to a perceived injustice - including sexual rejection.
The findings are reported in the British Journal of Psychiatry.
The team, led by Rosemary Purcell at the University of Melbourne, looked at 299 restraining orders from the city's children's court that met the criteria for stalking.
A significant minority of the juvenile stalkers (36%) were female - a far higher proportion than found among adult stalkers, researchers found.
Bullying, retaliation and rejection were among the main reasons for juvenile stalking, with sexual predation accounting for just 5% and infatuation for 2%.
Three-quarters of the victims reported being threatened.
These ranged from veiled threats such as "watch your back", to explicit threats to harm, rape or kill.
In 15% of cases, threats of violence had been made against the victim's family or friends as well.
While male adolescent stalkers mainly pursued girls, female stalkers tended focused their harassment on other girls.
They also often recruited their friends as accomplices to the stalking.
The report said: "Stalking behaviour in juveniles has traditionally been trivialised as uncommon and innocuous. This study provides the first systematic examination of juvenile stalkers.
"Juvenile stalking is characterised by direct, intense, overtly threatening and all too often violent forms of pursuit," the authors wrote.
"The seriousness that is afforded to adult forms of stalking should similarly apply to this behaviour among juveniles, given the even greater risks of disruption to the victim's life and risks of being attacked."
Dangerous form of bullying
Emma-Jane Cross, chief executive of Beatbullying, said: "The research further proves that juvenile stalking is a very dangerous form of bullying and one that is likely to escalate to youth-on-youth violence.
"Early intervention and on the ground bullying prevention work in schools and local communities needs to be part of the solution, with young people at the heart of implementing change."
Dr Emma Short, an expert on stalking at the University of Bedfordshire, said the research demonstrated the importance of recognising the physical, social and psychological impact that harassment can have adults and children.
She said: "The risk of lasting trauma and disruption is evident, and to some extent may be increased for children.
"One consistent finding that has emerged from research with adult survivors of stalking is that the majority report enforced lifestyle changes, such as job change, moving house, even changing times and routes of travel.
"Children have much less power over the shape of their lives and may encounter further difficulties by trying to keep themselves safe without the involvement or agreement of adults responsible for their care."