As the economy sinks and investors buckle over, the behavior buffs are rising up. From the lesser-appointed corners of academia, psychologists, sociologists and a youthful breed of economists scoff at the revered mathematical models that have driven economic thought and snared Nobel Prizes. These preachers of “behavioral economics,” including some on President-elect Barack Obama’s economic team, argue that humans cannot be relied upon to obey the efficient, orderly tenets espoused by free-market thinkers.