Violent behaviour dramatically increases during puberty,
according to a study of almost 6000 adolescents in Victoria,
Australia and Washington State, USA.
Students in Years 5, 7 and 9 were asked in a survey how many
times in the past year they had either attacked someone with the
idea of seriously hurting them or beaten up someone so badly that
the person required medical treatment. Adolescents in the late
stages of puberty were almost four times more likely to admit to
such behaviour than those in early puberty.
The study, by the Murdoch Childrens Research Institute in
collaboration with the University of Washington, has prompted calls
for prevention programs targeting youths during puberty to reduce
violent and antisocial behaviour.
"There is a common perception that violence and antisocial
behaviour increases during puberty but this is the largest study to
date to confirm the link," said lead researcher Professor Sheryl
Hemphill, of the Murdoch Childrens Research Institute.
"The rise in violence during puberty may be explained by
biological changes and social changes in adolescent peer groups,
and demonstrates the need to implement prevention programs through
schools, with families and in communities to reduce violence during
this time."
The study, published online today in American journal
Pediatrics, found that of students who admitted to violent
behaviour, 47 per cent were going through late puberty, 43 per cent
were in mid-puberty and just 10 per cent were in early puberty.
Overall, 10.8 per cent of Victorian boys reported violent
behaviour compared with 6.5 per cent of Washington State boys.
Violent behaviour was significantly lower among girls in both
Victoria (3.2 per cent) and Washington State (4.5 per cent).
Problems at home and associating with violent peers increased the
odds of violence among adolescents in mid and late puberty.
Meanwhile, boys and girls in early puberty were more likely to
resort to bullying including starting rumors about peers or
excluding students from their group of friends.
The findings form part of the International Youth Development
Study, an ongoing collaboration between the University of
Washington, Murdoch Childrens Research Institute, University of
Melbourne, Deakin University and the Royal Children's Hospital's
Centre for Adolescent Health.