Behavior Genetics

, Volume 28, Issue 6, pp 429–441

Correcting Estimates of Shared Environmental Variance for Range Restriction in Adoption Studies Using a Truncated Multivariate Normal Model

  • Mike Stoolmiller

DOI: 10.1023/A:1021685211674

Cite this article as:
Stoolmiller, M. Behav Genet (1998) 28: 429. doi:10.1023/A:1021685211674


A model is presented for the truncated trivariate normal distribution that arises in behavior genetic adoption designs that focus on sibling similarity to estimate shared environmental effects. The model estimates the point of truncation and shared environmentality. Both moment and maximum likelihood estimates are obtained numerically. Simulations indicate that the model and the numerical procedures perform well when they are most needed, that is, when shared environmentality is large, truncation is extensive or both. When applied to published data from the Texas Adoption Project, results indicate that the point of truncation is at about the 63rd percentile of the family environmental quality distribution (i.e., the bottom 63% is missing) and shared environmentality is about 55%. Implications for current views on the importance of shared environment for child developmental outcomes such as antisocial behavior and IQ are discussed.

Adoptionshared environmentIQtruncated distributionssibling resemblance

Copyright information

© Plenum Publishing Corporation 1998

Authors and Affiliations

  • Mike Stoolmiller
    • 1
  1. 1.Oregon Social Learning CenterEugene