More bad news for the global economy: Men - who run everything, still - are so beholden to fluctuations in their ever-volatile, often-zany hormones they may doom the whole system through their inevitable, stupid, testosterone-fueled mistakes. So says a new book on biology's role in market behavior, based on research that analyzed traders' spit during market sessions and found, essentially, that men are having their periods all the time, so beware.

"Market participants aren't the rational automatons of most financial theory. They are biological organisms responding with a neural and physiological apparatus designed millions of years ago" - and possibly, not so well.