As of the end of the twentieth century, the United States is run by rules that are congenial to people with high IQ and that make life more difficult for everyone else.Herrnstein & Murray, 1994, p. 541
The quotation from The Bell Curve: Intelligence and Class Structure in American Life, is a pretty strong statement about the importance of intelligence. When Herrnstein and Murray made it they were attacked as elitist and antidemocractic. Other people, with impeccable democratic credentials, had said similar things in a less contentious way. Just a few years before Herrnstein and Murray wrote, Robert Reich, a sociologist who had served as Secretary of Labor in the Clinton administration, wrote that work has shifted from emphasizing the manipulation of objects to the manipulation of abstract ideas, varying from programming a robot to analyzing a financial system. It follows that skill in manipulating abstract concepts, intelligence, has become progressively more valuable over time. To what extent do cognitive tests predict such skill?
Problems in Investigating the Relationship between Intelligence and Success
This chapter examines the relation between intelligence and success in three broad regions; academics, the workplace, and personal life. These studies are not easy to do, for several reasons. First, we have to specify what we mean by success in each arena. Next, we have to select quantitative measures of success. Observable measures, such as grade point average or money earned, are frequently only partially satisfactory measures for our criteria.