Why increase the age to 21?
The National Minimum Drinking Age Act 1984 was passed by the US Congress on July 17th, 1984. This law required states to create laws setting the minimum age to purchase or publicly posses alcoholic beverages to 21. Did you know that states that do not comply lose 10% of their federal highway funds? Some states also ban the private consumption of alcohol by those under the age of 21, although this is not required by the Act. It was also determined by several studies that a youth's brain is not fully developed until about 21 years of age, and that because of that, alcohol affects youth's brains differently than it does an adults.
Sources:
http://voices.yahoo.com/what-legal-drinking-age-united-states-116132.html
Sources:
http://voices.yahoo.com/what-legal-drinking-age-united-states-116132.html