Children who are allowed to sip alcohol are more likely to drink by the time they reach ninth grade, a new study finds.

Researchers at Brown University found children who had sipped alcohol by the time they were in sixth grade were five times more likely to have a full drink by the time they were in ninth grade, CNN reports. They were four times more likely to binge drink or get drunk, compared with teens who hadn’t sipped alcohol when they were children.

The findings appear in the Journal of Studies on Alcohol and Drugs.

Study co-author Kristina Jackson told CNN, “I think the most important thing is to make sure that children know when drinking alcohol is acceptable and when it is not.” She added, “I would say that it is advisable not to offer your child a sip of your beverage, as it may send the wrong message — younger teens and tweens may be unable to understand the difference between drinking a sip and drinking one or more drinks.”

The study of 561 middle school students surveyed over three years found overall, a little under one-third said they had sipped alcohol by the beginning of middle school. Most said they got the alcohol from their parents at a party or on a special occasion.

Of those who had sipped alcohol when they were young, 26 percent said they had a full drink by the time they were in ninth grade, compared with 6 percent of those who had never sipped alcohol. Of those who had sipped alcohol early, 9 percent said they had binged (had five or more drinks in one sitting), or gotten drunk by ninth grade, compared with less than 2 percent of those who hadn’t sipped alcohol.