Comments on Immune Aspects of the Geschwind-Behan-Galaburda Model and of the Article of Bryden, Mcmanus, and Bulman-Fleming

The goal of this article is to reconsider the links among immune disorders, testosterone, and left-handedness made originally by Geschwind and Behan (1982) and by Geschwind and Galaburda (1985). We demonstrate that an excess of testosterone in utero is not a prerequisite for immune disorders, because of its destructive action on thymus, and that allergy and autoimmune disorders are not primarily thyme-dependent but B-lymphocyte-dependent. We furthermore study the HLA proposed by Yeo and Gangestad (1993) and retained by Bryden, McManus, and Bulman-Fleming as a possible variable that could explain, in replacement of testosterone, the link among allergy, asthma, and ulcerative colitis. We conclude that the HLA of lefthanders and the meta-analysis of Bryden et al. do not fit together as well as hoped for.