Kelsey Bennett had her first drink when she was 13. She doesn't think she was pressured by her peers. She doesn't think she was swayed by advertising. She just had a few friends over one night and opened some bottles in her parents' liquor cabinet.
"The older kids are drinking and having a good time, so why not, you know?" says Kelsey, now a student at the Berklee College of Music in Boston. "When you start drinking, it's kind of this mystery, something you can't do."
It's something that young people have long been forbidden to do, and done anyway. But the reality has been changing, with evidence that it is now girls such as Kelsey, not boys, who constitute the majority of youths using alcohol.
The gradual shift, which has only emerged over the past few years and has not been widely reported, raises questions about whether society understands enough about the different forces motivating boys and girls as they move from grade school to college.
Some factors affecting both sexes are obvious: Start with alcohol's huge presence in American culture, add more absent parents and rising rates of stress and depression among youths, and you have a cocktail of reasons explaining underage alcohol use.
Beyond that, many girls "want to be one of the boys," says Joseph Califano, president of the National Center on Addiction and Substance Abuse at Columbia University in New York. Also, in the center's studies of 12- to 17-year-olds, girls report far higher stress levels than do boys. That, along with more spending money, correlates with a greater propensity to drink.
Moreover, alcohol's disinhibiting effects can be alluring as a shortcut to girls who "feel enormous pressure to have sex." The push to be sexy often goes hand in hand with the pressure to drink. Experts say that's a factor that advertisers exploit, often to the detriment of girls more than boys. "Bad girls make good company," reads one ad for Cuervo rum. In a Martell Cognac ad, a sultry woman is on display with a plea to "Be at least capable of bad."
To be sexy, goes the logic, is to drink, says Jean Kilbourne, a visiting research scholar at the Wellesley Centers for Women. And more subtly, alcohol goes beyond being a tool of seduction, promising empowerment, liberation.
The role that ads may play is highlighted in a study released this week by the Center on Alcohol Marketing and Youth at Georgetown University in Washington. The group looked at the advertising content and readership ages of popular magazines such as Vogue, Cosmopolitan, Maxim, and Sport Illustrated. The study found that underage youths saw more alcohol advertising than did adults in 2002 - and that teen girls were far more likely to be exposed to that advertising than teen boys.
For example, while underage boys saw 29 percent more beer advertising in 2002 than legal-age men, underage girls saw 68 percent more such advertising than legal women. The disparity is just as striking in the "malternative" market (malt-based drinks), where boys saw 37 percent more such ads than legal-age men, while girls saw 95 percent more advertising than legal-age women.
Ashleigh, a teenager who recently graduated from a New Jersey boarding school, says marketing definitely plays a role in her friends' decisions to drink. "I don't think it's considered unladylike to drink a lot," she says. "Look at college girls. They are always depicted in the media as getting trashed and they look cool."
The numbers don't surprise Susan Foster of Columbia's center on addiction. "Targeting women is nothing new," she says. "The alcohol industry, just like the tobacco industry, knows that if you want a lifetime heavy drinker, the best way is to start them early."
Watchdog groups have long criticized the industry's marketing tactics, which are self-regulated. Georgetown issued a report less than a year ago finding that up to 60 percent of visitors to alcohol company websites were minors, citing games and music on the sites that may be most alluring to an audience younger than 21.
Jim O'Hara, executive director of the Center on Alcohol Marketing and Youth, says his study measured ad practices that precede the industry's promise to market to an audience of 30 percent minors or less - a big step from the 50 percent limit imposed prior to 2003.
Estimates of alcohol use among teenagers have ebbed and flowed over the years. The number of high school seniors who said they had taken five or more drinks in a row during the past two weeks, for example, fell from about 37 percent in 1975 to 28 percent in 1993, but edged back up to 29 percent in 2002, according to Monitoring the Future at the University of Michigan at Ann Arbor.
In a shift since 2002, girls now outnumber boys in using alcohol. The group Leadership to Keep Children Alcohol Free, for example, cites 2002 research showing that 38.5 percent of ninth-grade girls reported drinking in the past month, versus 34 percent of boys. Some 21 percent of girls and 19 percent of boys reported binge drinking. Until that year, girls had reported consuming alcohol at rates less than or nearly equal to boys.
The factors influencing young people go far beyond advertising. For teenagers in particular, alcohol can be inextricable from the transformed climate of sexual experience, including an emphasis on "hooking up" for casual encounters. "One reason girls are drinking so much is that it's pretty hard to have these kinds of relationships sober," says Ms. Kilbourne. "It's easier to have meaningless sex when you're drunk."
With many teenage girls already losing confidence - studies show that girls' self-esteem plummets in adolescence - Kilbourne and others point to alcohol as a means of short-lived escape. "Most teenage girls have been led to feel terrible about themselves, and alcohol can make you feel beautiful, witty, all kinds of things - or at least make you not care."
There is strong evidence, too, that alcohol abuse is far more common among those with eating disorders, the Columbia center announced in December - and most such disorders develop among teen girls. Also, peer pressure to drink appears to sway teen girls more than it does boys, according to a study released the following month by the National Institutes of Health in Washington.
The impacts can be far-reaching. Youths who start drinking in their mid-teens are more likely to become alcoholics, and alcohol is a factor in leading causes of teen deaths: accidents, murder, and suicide.
Particularly among girls, heavy drinking can launch a perilous cycle. One drink for a teenage girl has roughly the same impact as two drinks for a teenage boy, due to lower body weights and different metabolisms, says Mr. Califano.
Adult women still drink less than men do, and are less likely to drink heavily, but that gap is closing among young girls, Dr. Foster says.
One answer, some argue, involves holding parents more accountable. "Advertising is one thing, but just the prevalence [of alcohol] itself is normalizing," says Bruce Simons-Morton, who led the NIH study on peer pressure last year. "So those parents who continue to be highly involved with their kids, to monitor their behavior - their kids are less likely to" drink.
Meredith Maran, author of "Dirty: A Search for Answers Inside America's Teenage Drug Epidemic" and a mother of two, is concerned but also seeks to avoid alarmism. "How many decades are we going to study drug use instead of looking at what causes kids to do drugs?"
• Carly Baldwin in New York contributed to this story.