Between ages 5 and 7, being the victim of a bully at school uniquely contributes to a child's behavioral and emotional problems, according to observations of children before and after 2 years of bullying.
Youngsters targeted by bullies often enter school already showing signs of maladjustment, but those problems worsen and expand over 2 years of bullying, say psychologist Louise Arseneault of the Institute of Psychiatry in London and her colleagues.
The researchers studied 2,232 English and Welsh children born in 1994 and 1995. The sample consisted of pairs of healthy identical and fraternal twins. Experimenters obtained reports from mothers and teachers about the children's behavior problems and school adjustment at age 5 upon entry into school and again at age 7.