Parents do have an influence on teens’ decisions about drinking, according to a new survey by Mothers Against Drunk Driving (MADD). Teens are much less likely to drink if their parents tell them underage drinking is completely unacceptable, the survey found.

The online survey of 663 U.S. high school students found only 8 percent of teens who said their parents thought underage drinking was unacceptable were drinkers themselves, HealthDay reports. In contrast, 42 percent of teens who said their parents believed underage drinking was somewhat unacceptable, or completely acceptable, were drinkers.

Teens whose parents told them underage drinking is completely unacceptable are 80 percent less likely to drink, compared with those whose parents give their teens’ other messages about drinking, the survey found.

“Decades of research show that there is no safe way to ‘teach’ teens how to drink responsibly,” Robert Turrisi, a professor and researcher at Pennsylvania State University, said in a MADD news release. “A clear no-use message is the most effective way for parents to help keep teens safe from the many dangers associated with underage alcohol use. This issue is too important to leave to chance and hope for the best.”

In conjunction with the survey, MADD launched a new campaign that encourages parents to tell their teens not to drink if they are under 21. Not everyone agrees with MADD’s message, including John McCardell, former president of Middlebury College. In 2008, McCardell joined with more than 100 other college presidents to demand reconsideration of the national drinking age in 2008, U.S. News & World Report notes.

“Are they saying that drinking on the day one turns 21 is OK? Are they saying that they expect everyone under 21 to abstain and to wake up on their 21st birthday prepared to make responsible decisions about alcohol consumption?” McCardell said. “Do they really believe it is that simple? Many of those who turn 21 will no longer be at home or under parental influence. To whom, then, do they turn, to learn about responsible alcohol consumption?”