Those who attack The Bell Curve and its claim that IQ is the most important factor behind economic and social success in America are getting new ammunition. A National Bureau of Economic Research paper by Sanders D. Korenman of the University of Minnesota and Christopher Winship of Harvard University reanalyzes the data behind the late Richard J. Herrnstein and Charles Murray's conclusions--and throws cold water on their judgment.
The NBER study argues that The Bell Curve's estimates of the impact of IQ are overstated because Herrnstein and Murray rely on too narrow a measure of parental social and economic status--based on education, occupation, and income only. Winship and Korenman add other important elements to family background, such as whether a child grew up in a single-parent household and lived in an urban neighborhood. Their expanded measure finds a dramatically bigger effect from family background on socioeconomic outcomes. Korenman and Winship go on to estimate that the effects of family background could be as much as two to four times as large as the effect of IQ. The result: Native intelligence is only one of several factors determining who gets ahead.