Children allowed an occasional sip of wine at the dinner table may be more at risk of drinking as teenagers.
Of 561 children in a US study, those given a taste of alcohol by the age of 11 were four times more likely to have been drunk or to have experienced binge-drinking by the time they were in high school.
Sips of alcohol at a young age may give young children a "mixed message", according to lead researcher Dr Kristina Jackson, from Brown University in Providence, Rhode Island.
"At that age, some kids may have difficulty understanding the difference between a sip of wine and having a full beer."
The findings, published in the Journal Of Studies On Alcohol And Drugs, are based on a three-year survey of school children in Rhode Island.
At the start of sixth grade, at around age 11, almost 30 per cent of the children said they had experienced at least one sip of an alcoholic drink.
In most cases the drink was provided by parents, often at a party or other special occasion.
By high school - when they were aged 15 to 18 - 26 per cent of the early "sippers" but only six per cent of "non-sippers" reported having "downed" a full alcoholic drink at least once.
Nine per cent also confessed to getting drunk or binge drinking compared with just two per cent of "non-sippers".
Dr Jackson said the popular idea that introducing children to alcohol early might lessen the "taboo" appeal of alcohol could be wrong.
"Our study provides evidence to the contrary," she said.
The researchers took account of factors that influence under-age drinking, including parents' drinking habits, parental history of alcoholism, and character traits such as risk-taking and impulsiveness.