Response to Commentaries: Meta-Analysis of Probability Samples and Other New Evidence
I am happy to respond to the eight interesting and thought-provoking Commentaries on my recent meta-analysis of the fraternal birth order effect (FBOE), that is, the finding that older brothers increase the odds of homosexuality in later-born males (Blanchard, 2017). Some of the Commentaries focused on my empirical evidence for the reliability of this statistical effect; other Commentaries focused on my theoretical explanation for the existence of the effect, namely the maternal immune hypothesis. The maternal immune hypothesis(MIH) is the hypothesis that the FBOE reflects the progressive immunization of some mothers to male-specific antigens and the consequent effects of anti-male antibodies on sexual differentiation in the brain in male fetuses. As one might expect from the authors’ diverse academic backgrounds and research specialities, some of the Commentaries addressed matters that fall outside the two foregoing headings. In what follows, I try to address the main...
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