One interesting topic that came up in yesterday's coalition meeting was the need to educate parents and others about the reason for the age 21 drinking limit. Evidently, people did a poor job explaining the science behind our attempts to delay young people's exposure to alcohol and drugs, but there is good reason.
Brains under construction: Neuroscientists have determined that the adolescent brain is going through a specific "pruning" process, wherein the myriad of underused connections that were established in childhood are being severed. This process makes adult brains function much more efficiently than those of adolescents and children. The thing is, this process is development--it is akin to mixing up cake batter for a recipe, albeit a recipe that takes about 12 years to complete. Adding substances to the mixture can have pretty serious consequences. Messing with the brain chemistry of youths by overstimulating their dopamine receptors, etc., can have unpredictable, negative outcomes.
Additional vulnerability: Brains mature from the back/bottom (the brain stem area from where fundamental processes arise) to the top/front (where judgement lives). This bit of trivia means that young people are often more likely to experiment and disregard consequences than they would be after the full development of the frontal cortex.
Correlation between early exposure and later alcohol problems: The average age of first use of alcohol in Texas is 13.5 years old. Statistically, the later a person begins using alcohol, the less likely he or she is to develop an alcohol abuse problem later in life. In the chart below, you can see that youth who begin drinking prior to age 15 have a 40% likelihood of having serious alcohol issues in adulthood. But the later we can delay their exposure to alcohol, the better their odds become, with young people beginning to drink around age 21 having only a 10% chance of serious alcohol issues.
Basically, any one of these points is reason enough for responsible community members to rally against youth access to alcohol and other substances. From a public-health standpoint, the 21 drinking age is well justified.
References
Sequeglia, L. M., et. al. "The Influence of Substance Abuse on Adolescent Brain Development."Clin EEG Neurosci. 2009 January ; 40(1): 31–38.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2827693/pdf/nihms177745.pdf
SAMA Foundation. "The Effects of Drugs and Alcohol on the Adolescent Brain." http://samafoundation.org/youth-substance-addiction/effects-of-drugs-on-adolescent-brain/
US Department of Health and Human Services. "Alcohol and the Developing Brain." http://www.toosmarttostart.samhsa.gov/families/facts/brain.aspx
