Behavior Genetics

, Volume 35, Issue 2, pp 211–217

Reformulating and Simplifying the DF Analysis Model


DOI: 10.1007/s10519-004-1020-y

Cite this article as:
Lee Rodgers, J. & Kohler, HP. Behav Genet (2005) 35: 211. doi:10.1007/s10519-004-1020-y


DeFries-Fulker (DF) Analysis for unselected populations is reformulated as a no-intercept model with centered variables and only two independent variables. The reformulation serves three purposes. First, the original formulation implicitly estimated two different values for c2 and two values for h2 . The new formulation resolves this ambiguity. Second, because the original formulation estimated h2 with the coefficient from a regression-interaction term, whether to center the interaction variables was unclear. The new formulation explicitly resolves this issue. Finally, the new formulation estimates fewer parameters, and therefore improves estimation efficiency and statistical power.


Biometrical modeling DF analysis heritability estimation 

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  1. 1.Department of PsychologyUniversity of OklahomaNormanUSA
  2. 2.Department of SociologyUniversity of PennsylvaniaPhiladelphia

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