The evolutionary genetic underpinnings of schizophrenia: the developmentalinstability model

The importance of genes in the etiology of schizophrenia is well known, but the manner in which the relevant genomic factors influence neural developm ent and the nature of selection forces operating on these factors are poorl y understood. In several prominent papers, Crow has provided a unique and c omprehensive theory that attempts to deal with these issues. A central aspe ct of his theory is that a single gene leads to reduced cerebral lateraliza tion, increased ventricular size, and risk for developing schizophrenia. He relies greatly on Annett's right shift theory of individual variation in h andedness. An alternative approach, based on the construct of developmental instability, provides a different way to conceptualize genetic influences, selection forces, and atypical lateralization in schizophrenia. We suggest that the developmental instability model has stronger empirical support an d is better grounded in contemporary evolutionary genetics. (C) 1999 Elsevi er Science B.V. All rights reserved.