The Magnitude and Components of Change in the Black-White IQ Difference from 1920 to 1991
A Birth Cohort Analysis of the Woodcock-Johnson Standardizations

The black-white difference in test scores for the three standardizations of the Woodcock-Johnson battery of cognitive tests is analyzed in terms of birth cohorts covering the years from 1920 through 1991. Among persons tested at ages 6-65, a narrowing of the difference occurred in overall IQ and in the two most highly g-loaded clusters in the Woodcock-Johnson, Gc and Gf. After controlling for standardization and interaction effects, the magnitude of these reductions is on the order of half a standard deviation from the high point among those born in the 1920s to the low point among those born in the last half of the 1960s and early 1970s. These reductions do not appear for IQ or Gc if the results are restricted to persons born from the mid-1940s onward. The results consistently point to a B-W difference that has increased slightly on all three measures for persons born after the 1960s. The evidence for a high B-W IQ difference among those born in the early part of the 20th century and a subsequent reduction is at odds with other evidence that the B-W IQ difference has remained unchanged. The end to the narrowing of the B-W IQ difference for persons born after the 1960s is consistent with almost all other data that have been analyzed by birth cohort.

Click here to read the full article as an Adobe Acrobat PDF.

Charles Murray is the W. H. Brady Scholar at AEI.

Also Visit
AEIdeas Blog The American Magazine
About the Author

 

Charles
Murray
  • Charles Murray is a political scientist, author, and libertarian. He first came to national attention in 1984 with the publication of Losing Ground, which has been credited as the intellectual foundation for the Welfare Reform Act of 1996. His 1994 New York Times bestseller, The Bell Curve (Free Press, 1994), coauthored with the late Richard J. Herrnstein, sparked heated controversy for its analysis of the role of IQ in shaping America’s class structure. Murray's other books include What It Means to Be a Libertarian (1997), Human Accomplishment (2003), In Our Hands (2006), and Real Education (2008). His most recent book, Coming Apart (Crown Forum, 2012), describes an unprecedented divergence in American classes over the last half century.


    Follow Charles Murray on Twitter.
  • Assistant Info

    Name: Caroline Kitchens
    Phone: 202-862-5820
    Email: Caroline.Kitchens@aei.org

What's new on AEI

image The Census Bureau and Obamacare: Dumb decision? Yes. Conspiracy? No.
image A 'three-state solution' for Middle East peace
image Give the CBO long-range tools
image The coming collapse of India's communists
AEI on Facebook
Events Calendar
  • 14
    MON
  • 15
    TUE
  • 16
    WED
  • 17
    THU
  • 18
    FRI
Wednesday, April 16, 2014 | 10:00 a.m. – 11:00 a.m.
Calling treason by its name: A conversation with Liam Fox

Join us at AEI as the Right Honorable Liam Fox sits down with Marc Thiessen to discuss and debate whether America’s intelligence agencies have infringed on the personal privacy of US citizens.

Thursday, April 17, 2014 | 4:00 p.m. – 5:00 p.m.
The curmudgeon's guide to getting ahead

How can young people succeed in workplaces dominated by curmudgeons who are judging their every move? At this AEI book event, bestselling author and social scientist Charles Murray will offer indispensable advice for navigating the workplace, getting ahead, and living a fulfilling life.

Event Registration is Closed
No events scheduled this day.
No events scheduled this day.
No events scheduled this day.
No events scheduled today.
No events scheduled this day.
No events scheduled this day.