Studies in the NDL use a family-study approach, which include individuals affected by autism and fragile X, as well as in relatives who themselves do not have these conditions. By studying how different complex traits run in families, we are learning how these different abilities may relate to genes associated with autism and fragile X, and also interact with environmental influences. Several of our studies also examine specifically how the FMR1 gene may contribute to language and other abilities in carriers of the FMR1 gene in its premutation state, and in the general population. As many as 1 in 150 women carry the FMR1 premutation, which has been shown to relate to subtle language and personality traits. The goal of this work is not only to understand the role of this gene in autism and fragile X, but also to help us understand the genetic basis of complex human traits that we all share.