Central to this proposal are the general genetic background and environmental perturbations that combine developmentally via epigenetic processes leading to the schizophrenic phenotype. Developmental instability (DI), the degree to which an individual's developmental trajectory is disrupted due to environmental perturbation, is associated with increased degrees of genomic homozygosity. DI is indexed by fluctuating asymmetry of bilateral traits and deviations from anticipated asymmetries of lateralized traits. Data collected on the MZ twins discordant for schizophrenia studied by an NIMH study include neuroanatomical, dermatoglyphic, minor physical anomaly, neuropsychological, and electroencephalogram measures, all of which can be transformed into markers of DI. Up to the present, the data sets from the twins have not been combined across sub-investigators for multivariate analyses. This project proposes multivariate analyses to draw these independently collected data sets together into a cohesive etiological explanation by examining them under a developmental instability framework. Positive results from this project will form the basis for the incorporation of these genetically informed concepts with further training experiences and collaborative efforts at other research centers conducting neurodevelopmental investigations of schizophrenia and related neuropsychiatric phenotypes.