MONTREAL - Children, especially girls, may be more likely to have sex before the age of 14 if they have been verbally abused by teachers, a new study suggests.

The study, which followed 312 children from kindergarten to age 23 in a rural Quebec town, also draws a link between peer rejection and girls engaging in early sexual intercourse.

"The girls seem to suffer more from these negative social experiences,'' said Mara Brendgen, the study's lead author.

"Girls, generally, are a bit more oriented towards social relationships and suffer more if these social relationships go sour.''

Researchers found children at elementary school who were shouted at, harshly criticized or embarrassed by teachers in the classroom had an increased risk of early sexual intercourse.

These students often disengaged from normal expectations and many turned to generalized delinquency, said Brendgen, a psychology professor at the Universite du Quebec in Montreal.

"(Often) it's the same children who are delinquent, who take drugs who also engage in risky sexual behaviour,'' she said.

Sexually active girls under 14 are more at risk of having multiple partners, which increases their chance of contracting a sexually transmitted disease or becoming pregnant, she added.

The study, published last week in the October issue of the American Journal of Public Health, also suggests that students who were criticized or laughed at by peers developed a lower self esteem.

Brendgen said some girls used sexual intercourse to give their battered self esteem a lift.

"Basically, it's a similar experience that they have from the teachers as they have from peers, in the sense that they are really publicly humiliated and exposed,'' she said.

Meanwhile, it's the disruptive students who were most frequently targeted, she added.

"It's not random,'' Brendgen said. "These children have certain behavioural characteristics that may provoke either their peers or the teachers into negative behaviour.''

Brendgen estimates between 10 and 15 per cent of children are regularly abused by teachers, while the same percentage are rejected by peers.

Neil Guilding, a co-ordinator at Head and Hands, a Montreal youth-assistance centre, said many adolescents complain about being singled out by their teachers.

"There are definitely situations where certain youths are being picked on all the time,'' he said.

Guilding believes rejection by teachers and classmates can increase the chance of drug use and criminal activity down the road.

"I think school can be a very lonely and scary place,'' said Guilding, who runs the centre's drop-in program.

Brendgen, meanwhile, said teacher training should highlight the potential consequences of negative behaviour toward students.

"Teachers need to have a lot more training, but also a lot more support in dealing with problem children,'' she said.

"On the side of the children, it is also important to maybe think about targeted interventions to help them develop positive relationships with their teachers and with their classmates.''

The study, which began assessing children in 1986, was funded by grants from the federal and Quebec governments.