What makes one brother a star and another a flop?
How to explain Bill and Roger Clinton? Dalton Conley, a sociology professor at New York University and the author of The Pecking Order: Which Siblings Succeed and Why (Pantheon) studied Census data and 175 siblings for answers. Conley points not to birth order but to family size and economic influences. "Inequality," he says, "begins at home." TIME spoke with Conley:
What is the family pecking order?
The pecking order is the hierarchy within the family based on the class or socioeconomic status of the adult kids. I define class by four...