Assessing the legacy of the GBG model

A critique of the article by Bryden, McManus, and Bulman-Fleming ("Evaluating the empirical support for the Geschwind-Behan-Galaburda model of cerebral lateralization") is presented. Bryden et al. expose some of the principal weaknesses of the cerebral lateralization model put forth by Geschwind and colleagues and contribute an important meta-analysis of findings concerning the model's predicted relationship between immune disorders and handedness. Nonetheless, the theory put forth by Geschwind and colleagues retains an important legacy despite a multitude of faulty assumptions and predictive failures. Also offered is a brief synopsis of a new model that explains the many positive relationships found among various neurodevelopmental disorders and medical conditions, as well as why abnormal handedness distributions occur in some but not other neurodevelopmental disorders.