Genome wide association studies use "phenes" or "traits" (symptoms) to distinguish groups in the human population. These groups are then employed to identify associations with genetic alleles that are more common in the symptomatic group than in the asymptomatic control group. Allen et al. report that with respect to Schizophrenia "Research in molecular genetics has focused on detecting multiple genes of small effect" This indicates the importance of discovering individual traits or "phenes" that are governed by single genes. Schizophrenia or bipolar disorder may be described as a phenotype but how many individual traits or "phenes" contribute to these phenotypes? Very large genome wide association studies have not found many significant gene linkages. On the contrary the results of these studies implicate a large number of gene alleles that have a very small effect (phene).