Moreover, even if heritability by itself does not translate into successful gene finding, the fact that a valid endophenotype reflects genetic risk can be used in novel ways. For instance, longitudinal designs can characterize trajectories of change in endophenotypes and factors that influence such trajectories, including environmental factors, which may improve our ability to predict who is going to develop a disorder as well as enhance our understanding of the genetic risk captured by the endophenotype. Understanding the potentially dynamic relationship between endophenotype and clinical phenotype and the parameters affecting it is important. Anxiety appears to relate to increased ERN differently in young children relative to older ones (Meyer et al., 2012). The reduction in P300 amplitude characteristic of children and youth at risk for substance abuse appears to become attenuated in early adulthood (Carlson & Iacono, 2008; Hill et al., 1999), suggesting that the utility of this endophenotype may be limited in this developmental period. Because gene expression is itself dynamic, it is also important to consider age and development when searching for genetic variants influencing a candidate endophenotype;
