Early male friendship as a precursor to substance abuse in girls

The findings show that girls tend to initiate the transition to a mixed-gender friendship network earlier than boys, and continue this transition at a faster pace during adolescence. As a result girls who experienced this transition early and fast were more likely to develop substance abuse problems during late adolescence.

Researchers followed a sample of almost 400 adolescents (58% girls), aged twelve to eighteen, from a large French-speaking school district in Canada. They were interviewed annually over a seven-year period about their friendship network and their use of alcohol and drugs.

Lead author Dr. François Poulin, "Peer relationships are considered to be one of the main risk factors for substance use. However, for boys, the formation of other-sex friendships is not associated with later substance use problems. Boys reported receiving higher levels of emotional support from their other-sex friends, whereas girls receive more support from their same-sex friends. 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 behavior."

The study finds that among girls, antisocial behavior and early pubertal maturation accelerated the increase in the proportion of other-sex friends. Compared to their same-sex friends, girls tended to form friendships with older males in out-of-school contexts. Since the legal drinking age is 18 in Canada, it may simply be more difficult for younger girls to purchase their own alcohol, thus older boys become one point of access for this substance. The study findings imply that parents may wish to take a more active role in monitoring their daughters' friendships, especially with older boys.

The authors maintain that by middle adolescence, once this transition has been completed, the impact of other-sex friendships on girls' maladjustment fades away. Mixed-gender networks then become more normative and girls are more likely to form romantic relationships with their male peers. The influence of boys on girls' substance-using behavior might then operate in the context of these romantic relationships.

The authors suggest that future studies should also examine the longitudinal associations between other-sex friends and other outcomes such as educational achievement and antisocial behavior. Finally, aspects of these other-sex friendships in early adolescence should be more carefully investigated, including the setting in which they take place, their linkages with the rest of the youth's friendship network, and parental supervision of these new emerging relationships.