This article on the importance of workers taking vacation quotes Mark Ketterer, a professor of psychology at Wayne State University in Detroit . He says more people should take as much vacation as possible because, among many reasons, research shows that death by heart disease is 40 percent higher in people who shun vacations. Most folks who don\'t take all their \"due time\" aren\'t paranoid or nuts, Ketterer says, as much as they are hyperconscientious and committed. \"I think culturally, we\'re nuts,\" he says. \"A friend said the United States is the only country in the world that takes vacations in order to be able to work harder. Everywhere else people work so they can take vacations. The result is to work yourself into an early grave.\"