Both Gender And Friendship Can Influence Adolescent Alcohol Use / ScienceDaily 26 November 2007
http://www.sciencedaily.com/releases/2007/11/071126162602.htm
"Adolescents who drink alcohol, smoke and/or use drugs tend to have peers who do the same. A new study that looked at other factors which may moderate the influence of peers has found that gender, and gender of friends, can also affect this association."
Gender Differences in Friends’ Influences on Adolescent Drinking: A Genetic Epidemiological Study Alcoholism: Clinical and Experimental Research
Alcoholism: Clinical and Experimental Research, Volume 31 Issue 12 Page 2012-2019, December 2007
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1530-0277.2007.00523.x
Danielle M. Dick, Jason L. Pagan, Candice Holliday, Richard Viken, Lea Pulkkinen, Jaakko Kaprio, Richard J. Rose