College students reduced their drinking more if their assumptions about alcohol's benefits were challenged than if they were warned about its dangers, psychologists say.

"We're looking at this as an approach to prevention" of problem drinking, said researcher Renelle Massey of the University of South Florida at Tampa.Study results support a theory that one reason people drink is because they think it will make them funny, brave, more sociable, sexier, more assertive or better in some other way, she said.

Levels of such "expectancies" have been linked to alcohol consumption in previous studies, she said in an interview Sunday at the American Psychological Association's annual meeting.

Her study, done with Mark Goldman of the university, included female college students who said they drank moderately.

After the students recorded their normal alcohol consumption for three weeks, 25 were assigned to a program to lower their alcohol expectancies, 25 others to a more traditional program that focused on the dangers of excessive drinking, and 27 received no training at all.

For one activity in the expectancies program, students of legal age were given either an alcoholic beverage or a placebo, but they were not told which. Afterward, the group played charades.

Then, those students and the under-age members of the group were asked to guess who had gotten alcohol, on the basis of their performance.

"Everybody made mistakes," Massey said.

Their inaccuracy led to a discussion of how people have been led to believe through television, advertising and everyday conversation that alcohol can make people sexy, funny and so on.