Note: As Mike Yassa, the lead author on the study, pointed out to me, the study did not actually test whether consuming caffeine before a task enhances memory, the problem being that other confounding factors can then lead to difference in performances on the test.
The US debt is more than $20.1 trillion, the largest in the world. Here are the 3 reasons it grew so large, and how it damages U.S. economic growth. The US debt is more than $20.1 trillion, the largest in the world.
As of 2009, there was $50.7 trillion of debt owed by US households, businesses, and governments, representing more than 3.5 times the annual gross domestic product of the United States. As of the first quarter of 2010, domestic financial assets totaled $131 trillion and domestic financial liabilities $106 trillion.