Correction to: Behavior Genetics (2008) 38:476–483 https://doi.org/10.1007/s10519-008-9219-y

After the publication of original article, the Editor was notified by Duke University that they have determined the authorship to be incomplete. Consequently, Dr. Edward Suarez has been added as a co-author to this article to represent his contribution to the conception and design of the work and acquisition of the data.