to future work evaluating similar hypotheses for endophenotypes. For the moment, however, we caution that we are not aware of studies that show developmentally heterogeneous genetic effects for our chosen endophenotypes at the ages we examined. For the one endophenotype that we have studied developmentally, P3 amplitude, the evidence suggests that the same genetic influences span adolescence to young adulthood (from age 17 to 24; Carlson & Iacono, 2006).
