using different indices of alcohol use and problems may help increase power to identify shared genetic influences, but may introduce noise if the gene under study is more specific to a particular aspect of AC. Creating multivariate genetic factor scores that take into account the extent to which different indices of alcohol use are reflective of the underlying genetic predisposition allows researchers to capitalize on all available information, while taking into account the differential informativeness of various indices of use. This illustrates 1 of the ways in which twin studies remain informative in the evolving era of gene identification.
