Pessimism = Advantageous

"Pessimism appears to have its advantages. A recently published paper observes that over the last three decades, the people of Denmark have consistently scored higher on life-satisfaction than any other Western nation. Why? Because, say the authors, the Danes are perennial pessimists, always reporting low expectations for the year to come. They then find themselves pleasantly suprised when things turn out rather better than expected."

"Research shows that we systematically exaggerate our chances of success, believing ourselves to be more competent and more in control than we actually are...this may help explain why hawkishness so often prevails at the national level."

You Are What You Expect
by Jim Holt
http://www.nytimes.com/2007/01/21/magazine/21wwln_lede.t.html?_r=1&oref=slogin