IOWA CITY (AP) - University of Iowa President Sally Mason says she won't support an initiative to study lowering the drinking age.

Presidents from about 100 well-known American universities have signed on the plan, known as the Amethyst Initiative. They hope it will help control binge drinking.

The plan is aimed at asking lawmakers to consider changing a federal law making 21 the defacto drinking age.

Mason told the initiative's founder that she will not endorse lowering the drinking age from 21 to 18. She says that because 19- and 20-year-olds can enter Iowa City bars, many underage patrons are drinking alcohol and getting drunk.