Conscientiousness isn't a measure of objectivity, it's a measure of reliability, the capacity to work diligently and adhere to rules. It correlates with income well because we're living in a very institutionalized society that rewards people who adhere to rules and follow expectations.
In the US it's basically what upper middle-class WASP culture is and it sustains a large share of income because it's very good at reproducing itself and managing organisations, it's all the lawyers, and bureaucrats, politicians and administrators and so on, it's all the people who're really good at making schedules.
In the US it's basically what upper middle-class WASP culture is and it sustains a large share of income because it's very good at reproducing itself and managing organisations, it's all the lawyers, and bureaucrats, politicians and administrators and so on, it's all the people who're really good at making schedules.