Skip to main content

Thinkstock

Miley Cyrus. Starter manicures. And all that fuschia. Parents of tween girls who fret over the intensification of girl culture have every reason to wish for a little co-ed influence in their daughters' lives. But a new study suggests they should be careful what they wish for.

In a new wrinkle to the common wisdom that peers have a big impact on behaviour, it turns out that male and female peers can operate very differently.

When it comes to substance abuse, girls appear to have a positive effect on boys, but boys have a negative effect on girls.

Girls who initiate friendships with boys in early adolescence are more likely to develop substance-abuse problems later in their teens, compared to the boys and girls who initiate those friendships later, according to new research by François Poulin of the University of Quebec at Montreal.

His study appears in the current Journal of Research on Adolescence.

Prof. Poulin and his colleagues followed about 400 adolescents (58 per cent of them girls) aged 12 to 18 for seven years, and regularly asked them about their friendships and their use of alcohol and drugs.

He found that unlike girls with male friends, boys who become friends with girls in early adolescence were not more likely to develop substance-use problems as older teens.

The reason? It may, paradoxically, have something to do with the emotional support girls offer. Boys who are friends with girls benefit; the girls lose out.

"Boys reported receiving higher levels of emotional support from their other-sex friends, whereas girls receive more support from their same-sex friends," Prof. Poulin said in a statement. "It is possible that having other-sex friends is protective for boys because they gain emotional support and are therefore less likely to engage in problem behaviour."

Among girls, antisocial behaviour and early puberty were also linked to the increase in the proportion of male friends they had.

Compared to their same-sex friends, girls also tended to form friendships with older males outside of the school environment. This could be significant because those older teens could be purchasing alcohol for them.

There's some good news, however. As girls age, the negative impact of other-sex friendships become less powerful as co-ed networks become the norm.

And before you ban all boys from your daughter's life until she's 30, know that the researchers are calling for more studies to examine the context of these friendships, including the settings in which they occur, a child's entire friendship network and, yes, the role of parental supervision on their children's friendships.

Interact with The Globe