Both Gender And Friendship Can Influence Adolescent Alcohol Use

"Several studies have found that peer drinking has more of an influence on an adolescent's drinking than his or her own parent's drinking," said Danielle Dick, corresponding author for the study. Now at Virginia Commonwealth University, Dick was an assistant professor at Washington University, St. Louis when this study was conducted.

"We wanted to more closely examine the role that gender may also play, because even though there are profound differences that occur in development between girls and boys during adolescence, little is known about how influences on alcohol use may differ between the sexes during this developmental period," said Dick.

Researchers used data from a population-based, longitudinal twin study of behavioral development and health-risk factors from Finland (n= ~ 4,700 individuals). They analyzed the association between friendship characteristics and alcohol use, testing for interaction with gender and gender of friends. They also used the twin structure of the data to examine the extent to which similarity in drinking behaviors between adolescents and their friends was due to shared genetic and/or environmental pathways.

"Our findings suggest that girls may be more susceptible to their friends' drinking," said Dick, "and that having opposite-sex friends who drink is also associated with increased drinking, for both sexes. Furthermore, genetically based analyses suggest that the correlation between adolescent/friend drinking was largely attributable to shared environmental effects across genders. This suggests that the association between an adolescent's alcohol use and that of his or her peers is not merely a reflection of genetic influences on the adolescent's own alcohol use that cause them to select drinking peers."

In other words, said Kenneth J. Sher, Curators' Professor in the department of psychological sciences at the University of Missouri, the influence of risk factors associated with the peer network appeared to be stronger in girls.

"Those who design and implement prevention approaches should take gender into account as a potentially critical moderator of prevention outcomes," said Sher. "We need to better understand the 'why' of sex differences in risk in order to shed important light on the nature of risk processes. For example, are girls potentially more 'vulnerable' to peer-related effects at this stage of life because they are likely to be more intimately involved with their closest friends than are boys" That is, does gender simply serve as a 'proxy' of a variable such as intimacy or closeness during this time of their lives?'"

Both Dick and Sher cautioned parents to be very aware of their child's friends, as well as how they spend their time together. "This awareness," said Dick, "is particularly important for girls, and when the friendship group consists of members of the opposite sex."

Sher suggested that future studies look more closely at how friendship networks change over time, and how that may affect alcohol use among peers.

"These investigations need to carefully consider the ages being studied because the extent that alcohol use is deviant changes rapidly over the course of adolescence, the relative importance of genetic and environmental factors appears to change, and the degree of gender differences in risk factors might also vary as a function of age," he said.

Results are published in the December issue of Alcoholism: Clinical & Experimental Research.

Co-authors of the ACER paper, "Gender Differences in Friends' Influences on Adolescent Drinking: A Genetic Epidemiological Study," were: Jason L. Pagan and Candice Holliday of Washington University, St. Louis; Richard Viken and Richard J. Rose of Indiana University; Lea Pulkkinen of the University of Jyväskylä, Finland; and Jaakko Kaprio of the University of Helsinki and the National Public Health Institute, Finland. The study was funded by the National Institute on Alcohol Abuse and Alcoholism, the Academy of Finland, and the Finnish Centre of Excellence Programme.