Here is a study showing that early alcohol exposure may lead to early drinking and other problem behaviours. American researchers looked at 450 children aged 8-18 and found that children who had sipped alcohol by age 10 were twice as likely to start drinking by age 14 or younger, compared with their peers who had not tasted alcohol when they were 10. Interestingly, however, earlier this year we published a study suggesting that early drunkenness, rather than age of first drinking, appeared to be associated with other problem behaviours. The researchers also found ethnic differences showing European Americans were more likely to begin drinking alcohol earlier than African Americans which confirms the relative importance of ethnicity in early drinking.
Types of Alcohol Use Experience From Childhood Through Adolescence - Journal of Adolescent Health
Many 8-Year-Olds in U.S. Have Tasted Alcohol: Study - Health Daily
'Remarkable study' highlights risk of early drunkenness - Mentor Foundation